Model Engine Maker

Engines => From Plans => Topic started by: mikehinz on September 18, 2022, 10:29:16 PM

Title: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 18, 2022, 10:29:16 PM
I've long admired the Jerry Howell designed Farm Boy.  Last year i completed an Upshur hit-n-miss engine and got that to run so I thought I might possibly have enough skill to get this engine built, even though it's more complicated in many respects.  So I ordered the plans and started going through them carefully. 

The front and rear frames and the water hopper weren't completely clear to me so i decided to start by modeling those pieces in Fusion 360.  That helps me to visualize how everything should go together and also starts to clarify in my mind, the Order of Operations, work holding, etc.  The JE Howell plans are excellent and I found almost no mistakes or omissions.  Any CAD modeling I did was really not necessary except to enhance my understanding of a particular part and/or to develop a drawing with ordinate dimension which I generally prefer. 

I THOUGHT I had some scrap bit of AL laying around that would be big enough for the major frame elements, but I was wrong.   So the first step was to get some material.  That will be in the next post.

I do want to explain something.  I've already gotten through most of the build, so I'll post the built log and photos fairly quickly until I catch up with where I'm actually at now.  So don't take the pace of posting as how fast I work!  I'm actually quite slow!   

I'll post fairly detailed photos and descriptions of what I found to be tricky so hopefully this build log will help others should they decide to tackle this very interesting engine.

Enjoy!

Mike. 
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 18, 2022, 10:57:47 PM
Since I needed some larger aluminum bar stock than anything I had on hand, and I live on the outskirts of Wichita, KS I took a trip to the famous Yard Store and spent an hour or so with measuring tape in hand, to find a suitable chunk of Al.  Here's a picture of just a small part of this metal supplier.

(https://lh3.googleusercontent.com/pw/AL9nZEWKb-PZwIAR8KrRjhymCCfgwpBQVwkhG3IpuwQfjHmasVxuONFBTU9eINbBDxnSZ6c-VH0evTPtGrqZmTxoV5kOm7S9I2rKZ_AL6ZEvsn8s2GeQJNx5tdBkpLX6kzd0iCAq_gA6gwEjEt32eD7pImGhnQ=w1274-h956-no?authuser=0)

Surely there's a Farm Boy lurking in there somewhere! 

The Yard does stock some new material, mostly round bar stock, but the majority of the material is Al drops and off cuts from the local aircraft industry.  I think the cost of the drops is around $2/lb, so it's by far the cheapest place to purchase stock.  Most of it is 6061 with some 7075 and 2024 thrown in occasionally.  The only downside of purchasing the cheap stuff is that it's almost never square or to standard dimension or it even has a clean face. 

After some searching I selected this piece, somewhere around 2 1/4 x 4 1/2 x 30".  Plenty for this engine plus some left for future projects. 

(https://lh3.googleusercontent.com/pw/AL9nZEVRVhPX2rvwM-z620J5mK9V5NMZi72L0_CFYBjlIjXeHiFaUi23MT0RCKatDPCPXS_2Ucmn4GM38ambusDuxCfhtGL_zuQQCeQgU2DfGWO-1BSGUr7Hbumzr-S52tgwyXh1tj8opBFBk-MK9rRZepVwmA=w1274-h956-no?authuser=0)

Then over to the horizontal bandsaw to cut off 3 slightly oversize chunks.

(https://lh3.googleusercontent.com/pw/AL9nZEXpvm6n6yY9ha1I8RuqY59FePVb-lXhabyHzSZYNxiP2um1Dm7S1PAkE7up8CA7vV2A7JOohQZZgH1-qL0E5LaLnKqiAxi5hAdf4z5sBLqKIMsysgXIXpu2Kp85aANjYjkDaqzXX4R-8tymRpa9BBMBtA=w781-h1041-no?authuser=0)

Starting to square up and bring to size one of the chunks.  I think I was using a 3/4" 2 flute end mill along with running my Unist mql system to avoid chips welding to the cutter.

(https://lh3.googleusercontent.com/pw/AL9nZEUrG2UGPUv3FKpgLXo5kO-HXyseBD_nfeMqn2jEN60U48AtIjqBysf5QjC_Pon-dnBHO4qtGkWuRAXERgoojzABsb-peqc4mBcDKzUlhO-ZmeWmn2OcmNuyr6GB_-2rcbUHW8x8wIZOXPMWmU4uJCtyag=w781-h1041-no?authuser=0)

I used a fly cutter for the final finishing passes in order to leave a good finishing on all sides.

(https://lh3.googleusercontent.com/pw/AL9nZEWi8Yixtwfb9_pQmtEqzd39v3yq0pGSds9cmO7XuYB51S89zN7O5hiLA_jAhTH2D4HE2jP1Wp_74Q3t6IxSM_zSb1aSiYp_5FutXY-baqLP4droZHXqdOTt4Gjl2S9Su6OeE6R-LEj6hKarFqKssbwA2w=w781-h1041-no?authuser=0)

And after a considerable amount of time and a lot of chips produced, I ended up with 3 properly sized blocks of Al that will become the front frame, the rear frame and the water hopper.

(https://lh3.googleusercontent.com/pw/AL9nZEVq0Ov1lfi7cVCX-uGMgPCGvFVSmECiNqzYGF8xUiCTXxR6YNDSKHhF0hA1gYwS_A9ZYfiY43cdwNTu0QU0CvQnznh2xWY2xUn3EHRDVRwFdAfIwawyj9m0nxLdEVq4wsJywwWFEEFQ2SGjynPFL1NMIw=w1274-h956-no?authuser=0)

That's it for today's posting.  Next will be starting to machine the frame and water hopper. 

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Bearcar1 on September 18, 2022, 11:07:12 PM
Mike, I just recently took ownership of a set of drawings for that engine and will be following along with great interest. That yard store looks like someplace I could spend an afternoon browsing around in. Good luck...


BC1
Jim
Title: Re: Farm Boy #876 - Mike's Build
Post by: RReid on September 19, 2022, 03:27:36 AM
Looking forward to seeing this one come together, Mike.  :ThumbsUp:
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 19, 2022, 10:03:53 PM
So on to some further work on the front and rear frames and the water hopper.  There's a LOT of work in these 3 pieces so I'll probably post this across several entries.  You'll also see some skipping around between pieces as I tend to do whatever work I can whenever I have a particular setup.  For example, if I have my 4 jaw chuck installed on my lathe, I'll do as much work as possible before I change over to collets or the 3J. 

I'm terrible at marking out, so I tend to use my mill to do whatever marking out I need to do.  Here I'm putting a small center hole in one of the pieces.  DRO's, edge finders, and DTI's are wonderful thing to achieve some pretty high accuracy!

(https://lh3.googleusercontent.com/pw/AL9nZEUXdgg4k3e9qvrmRRVxvtxV4FDE2hLMh5ZFstpdhpf8RTD57ESM3uGr2f69_o_VHR4lYq_YbMlbJOGyfK9ARaDxGgSnWUt065oCmORSAnI6WswzbF92kiMrOf_KgdxeT3ENfrQuru7D9-_gPT8TruhnXA=w784-h1041-no?authuser=0)

Here's the water hopper and front frame with the center holes positioned for reference for the next ops.  For the stock for the water hopper you can see a center hole on the front and on the top.  You can no doubt visualize what's coming next. 

(https://lh3.googleusercontent.com/pw/AL9nZEW66_KfidSYkVJXX4sfkSsh4el0AF_uXmo1P8UkVvCBy5OYsJfc_NwVzqAkGb6AqQ_uSxzl9wgcAnNeXfx8vQ2p2BVgDZgfq1nxtqxuTIB5FDQiYkvRUG7Y_ZOPRVxruDZMmK5CUXZTmAQ8k8Dw8zcKLQ=w784-h1041-no?authuser=0)

Over to the lathe with the 4j chuck installed.  You can see the general way i center an offset feature in the 4J.  The device in the tail stock is home made.  It's a thin rod about 14" long with a 60 degree point on the end and is held in a spring loaded base that's secured in the tail stock drill chuck.  Then I use a dial indicator to get the rod to run true near the stock.  I find that this method works well.

(https://lh3.googleusercontent.com/pw/AL9nZEVOhaYbLjzlZeWlOIBBFG6HhtJITGYmO9OdWbsn4g4cGclVIqhvYY1vybpcp_-4slSJJ3vGS8XzgpNnEHHoUMp04knBr2cjwnPjSmhomb9vYX_AfI3fi8KQiKvxvXxOPa6v785kQsK-ICR4jlWtUUemaQ=w784-h1041-no?authuser=0)

Once the center of the feature is found, I drilled thru up to 1"

(https://lh3.googleusercontent.com/pw/AL9nZEVFAvG1eaGMioUKgqLDTX0jo2-Q5vga_MAu_m_A8FsNQkV0QHX73dwR0UH0ZfZwK7u5l52m47unOVAsWd_OIMfkcxcO7R4VBZcKSOE_WbTht4SncH9CiWOiMhpbw79nbDEUVuUOEJC0V-1DWMZU_Ra8OA=w784-h1041-no?authuser=0)

Then I switched to a boring bar and bored all the way thru to 1.202" as per the drawing and then counter-bored to 1.50" ID to the depth spec'd on the drawing.  This is all done from the 'rear' of the front frame and this creates the first feature required.  The CAD model I built was really helpful as I added dims from whatever surface(s) that I used for reference 

(https://lh3.googleusercontent.com/pw/AL9nZEWnijKIbZJYMNkfRzngqwZbFfNrVatMTL6d9fTmG0DZ6-1iFvlVSyGMyDegz71bw4v9hWDF-a3k3TUtnD-y9hw37TKfppyNNiBkMaLolF9B_Umwva4V97TO_C2hUBgP4FNYhgUV6y2TUcUN0GzFEZSfjw=w784-h1041-no?authuser=0)

And here's the part with the lathe work done laid on the drawing.  You can see what the just created feature is when comparing to the isometric view on the drawing I made of the part.

(https://lh3.googleusercontent.com/pw/AL9nZEXihFeOr-qKBwZ7wGNfOPv8HH3fXgsMHZJpcg_mTXjZlv59aLZMPqlOrusaGa3oqUMa4nr0wgrwGTSFku72bTF1JU5im38iDFlgEPxRKJ8M6CN3sV4oAYi0IjkJ7BhHnoKi7LV18MgnvBPjU70ND2aBLA=w784-h1041-no?authuser=0)

Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 19, 2022, 11:15:22 PM
Next up is the water hopper top.  I wanted to make this now as I want to check the fit on the water hopper whenever I make that vs the other way around. 

I had some 2' "Al bar stock so I chucked a bit of it up and turned the OD to 1.782" as per the drawing.  I also drilled a .750 hole thru the center of the stock and here I've set the compound to 20 degrees and am starting to form the internal taper of the top.

(https://lh3.googleusercontent.com/pw/AL9nZEVLqyQ9HS9-vo17AN6dy3N8kK_JsP_zCF3ySOwJ-5dJH-9qCB9w_t4M7O1iGJ95RxKhPCawm4NPU6eg_8hIXukz4dSNDTjAeNcwMpBTTlan09VGjnkofnnjVsFRFmkukrJUodnBYOMItPVKe2Kqh5vWMQ=w784-h1041-no?authuser=0[img]

Here's another view of turning the internal taper using the compound. 

[img]https://lh3.googleusercontent.com/pw/AL9nZEVBPwdtdMPHg4Ij9FvYCE_veNKTVhW16wkgp7Hd7oXxuT0njk1HixntID7O5VB1Oze3m_Xum53oQwsRJ3BdtmbquhASGMxnPHST0idC3xXK709mtvGElebTIcibZdcGMRAlMr2F34wr0QEZ6vZEFkjEtA=w784-h1041-no?authuser=0)

Next I switched to a 3mm carbide round grooving tool and started forming the outside taper.  The compound angle stayed the same and simply progressed the cut until I got to the specified wall thickness of .100".  This tool also left a nice radius at the root of the cut very much like JE Howell's drawing. 

(https://lh3.googleusercontent.com/pw/AL9nZEU4hswLrWRbnUnPNKofeNxA0upfzjb7fy1BqVfFYBTjIo1a5yEM2YA4gKmB9WogGm9VBpMF9j2SInJkhW-D67qAWjdfmdabRFpczKW2vjyM3zN9xyLlWBPmAb4fT258eq2I8QXLDyMV--z9AsIo7A9TOg=w784-h1041-no?authuser=0)

Parting the hopper top off using a 2mm carbide parting/grooving tool.

(https://lh3.googleusercontent.com/pw/AL9nZEXh8G5maCw4FdSJPBd2Ua8KIYdx8wqSOvXtxspU9vgTxmRbTigoEq5aUw6TtZvlmcR0vl-hgQZ-3o4j5d-Jt1dwWwRxkRf4zVqn4Wd1bZ1ML-cpu0flLYaO0Gzvwlg8KNFiXveNExWzn1Kadc4WlHqZig=w784-h1041-no?authuser=0)

And here's the finished hopper top on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEWj-ADnlt8_KjdOR8iUFS9zu6bukbJAALHg8dALR13oDPky1sX3T2YYtksN9_vGN_x62Hno_cZy8ZswXgZ39pBivyOvVRve2ynNf4uTAJwL6kvIGz3qMZ_gynLbb1qxzQyghJ_sRZrs1x2i8tcvhiL1rQ=w784-h1041-no?authuser=0)

Then back to the body of the water hopper.  I centered on the previously made center hole and then using a 1" drill to remove as much material as I could from the block.  Here I'm finishing up with a boring bar, creating a 1.720" hole and then putting in a slight counter bore of 1.780" to .170" depth. 

(https://lh3.googleusercontent.com/pw/AL9nZEWKI0hhlxJKHt_l87hmwTH-BOmttzHT8gg90RTFYz3ohCgLZ5BU_TK0Z3iiQRAQEyKaP0Jbub-Xr0VEXa5rpGE0Vj_bGkfZ5ZLoLVNTjJ8ylnUAewjKMTvSDAuUgac7V93_2yaJ_DULMCyBtC8RAiIGUg=w784-h1041-no?authuser=0)

Here's the top feature of the part laid on the drawing next to the isometric view.  You can see the other center hole on the front of the part which will be used to reference the thru hole and counter bore(s) for the cylinder sleeve. 

(https://lh3.googleusercontent.com/pw/AL9nZEW3t3Tj-mYUfmutqLpYNBunODFKmBkae0ACzJ4Zlo2Fhfi7WEJhM6wjfNHZS31TLaJSIq-ML0glccSPQ4-KTXRjfnX3of4Xlqcd1w1-9LWiK2sIOpPMlD8YrepCtS-r4Ea8nfAXtp8TxfL7j263w2Wf6w=w784-h1041-no?authuser=0)

And lastly showing the top fitted into the water hopper body.  Fit was good and I'll end up fastening it using JB welding, but that will come much later.

(https://lh3.googleusercontent.com/pw/AL9nZEWhU57tsVonQ1SkMro0rbNNmJwKvRWvMmhblwNkPY6hPuT-7lepc-iL6IH2nDY-sxQvVRONIw8eEvu9AjbEq1m0tNlLPFUq1_jhLgdkcrq6ZRQ54amtIO3ee07KkMOsKIUJ8_gaPIyaxkuHXWx-zoolew=w784-h1041-no?authuser=0)

That's it for today's postings.

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: cnr6400 on September 20, 2022, 02:52:54 AM
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 20, 2022, 08:10:36 PM
Before drilling and boring the hole for the cylinder liner in the water hopper, I wanted to make the cylinder line first in order to be able to test fit it to the hopper.   

I started with some 1.5" cast iron stock that I'd ordered some time back from Hobby Metal Kits (highly recommended!).  After centering it the 4j chuck, I turned the 1.200" OD and the 1.355" 'ring' near what will become the top of the liner.  Then i center drilled and drilled just just under 1".   I think that's a 7/8" drill that I'm increasing the ID with. 

(https://lh3.googleusercontent.com/pw/AL9nZEXbpeodZXYioQh7H5Ycm3yFOKhnf9xamhTvarsbX1UNTvO8LR_Lh0kmUJenwKo41FgoOntMBsua-PPAcqBxcX3YnyUAUyVb7-gK70lF1jiNfGJVeP4R1kVG-2_B3lD_jlZxSX51R0WS2KVvXMpxdnD8-Q=w784-h1041-no?authuser=0)

Then I switched to a boring bar and carefully brought the ID to just under 1.000"  I do like machining cast iron as it always cuts easily with small chips.  I don't mind the carbon that gets everywhere either!

(https://lh3.googleusercontent.com/pw/AL9nZEUurMeem5EOWSSWezKWNauIOk_mdinTaoOmyKiw6Dpz8jn3CDn3z6WE_GXfL7aPBGYj4WqZKpJfhn1Th8tZ0s1kV_cRE-QjeJoGyTm_jjqDTjH_tHqsyP4MILW0RAoMTZPL1s9o_6Gsgye3DhJugA-nKg=w784-h1041-no?authuser=0)

Next I put a small chamfer to make installing the piston a bit easier.  That's just a HSS tool that I think I'd ground or threading, but it works fine to put a mild chamfer on a part also.

(https://lh3.googleusercontent.com/pw/AL9nZEUVita94wUbDWWWtup7V-upA7HVIzZmIU-Zqw6ZAkEvnie5UoXcovM4Rwbg5OJVhyvD9Kqie7JHaxj8D0n5rInVer7RJn1t9CFxdeD5BLFutCtyNFR60WkVqWiwqnklOz_B5Lb8iEqR4s3Efym0tx3uMg=w784-h1041-no?authuser=0)

Next I used a 2mm carbide parting tool to create the ring at the top of the liner and then to part it off from the stub stock. 

(https://lh3.googleusercontent.com/pw/AL9nZEXV7GpT7XTZb6g5jiZcYFqCAl5GEa1a5IZ69LcfMVhhDsTEPnHvjNY-xyxY92hYxH1_T4l-upFxkFEEj8t2uDaAoi6IRDqNsi0A-vbDiWc-OEP3E1IP6HZJAb35TSP3aQrpFhVBm_axhabHs9rOWOxjyA=w784-h1041-no?authuser=0)

And here's the cylinder liner on the drawing compared to the isometric view and the bottom view.

(https://lh3.googleusercontent.com/pw/AL9nZEVW7loB0AK1l6HNRFzWjfTG2Wxd2PTQulH8w3pdpJ2rPjgnIjFAoTGr1h_tSvv0GLuRNb2LxqN3ZPxWC2CoUV6d0nzfXvjsYIeUnl34cJnSEJ2w0lVYvAUiGGyqVQfDS4Cf6fwu_YL95fHX0gfsZ5mJGw=w784-h1041-no?authuser=0)

There's a hole oil that needs to be drilled at an exact distance from the front of the liner.  I VERY lightly clamped the cylinder in the mill vise, found the center and the right edge of the liner and then moved x to the spec'd distance and drilled with a #40 as spec'd.    I also very lightly scored the very front edge of the liner at the top center with a small center drill in order to create an index mark which is needed when installing the liner in the hopper.

(https://lh3.googleusercontent.com/pw/AL9nZEUKSZpI3ILLfh5gq0Fn8gvEvOxN0TkeyQDniVJ7nCkjTQCAruBc-YYDGTAqW7lhgCFtls6UHPR9bWAZapSBc7EibQ4HDVgHfA0mnSFiG5ybEtMEMFMK6NK18BX5tq8QfS3wcLOAku8zb65rCIhkQxbQsw=w784-h1041-no?authuser=0)

And last operation on this part was lapping the ID.  I used a 1" Acrolap and Timesavers lapping compounds, mixed with just a few drops of oil.  I progressed thru the 3 grades of the Timesavers and when finished, the ID of the liner was very smooth and close to a fully polished finish.  I turned the lap with my lathe set to the lowest speed of 90 rpm and then held the cylinder liner by hand while running the lathe with the jog button.  I did it that way as I could instantly release the button should something go wrong.  It's always interesting when lapping that you can feel the process progressing.  It starts out rather 'lumpy' feeling and the lap needs to be tightened quite often.  As things progress the feel gets much smoother and very little tightening has to be done. 

(https://lh3.googleusercontent.com/pw/AL9nZEW_zdFc6ifoGdbdXzRiRXZY0U1Q4ECa0GOmx0mgy6ZhZ60jO0p6XE0FdKFcXOqMmEQMFFVwXgPqhNcPg8F9ELRZngI83yrGwZYjftR6ofW3em5wcURHWnrOE-nHGu0RpjqjCbKGLZyPiWrXpdov7jmLkA=w784-h1041-no?authuser=0)

So that's one more part completed. 

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 22, 2022, 12:35:06 AM
In this post I'll show the rest of the work that i did to complete the hopper.  This part ends up with a LOT of labor to get it completed!

I decided to go against the Howell's suggestion on the drawing and did the thru drilling from the front side, mostly to eliminate one additional setup step.  Here I'm using an extended length drill to drill thru in 3 locs as per the drawing.  I actually generated my own drawing for this as I used the technique of centering up on the bore and then using the DRO stepping over in x and y to the required locations.  I did center drill each location and when drilling, I backed the drill out quite often as it's very easy to get the chips packed in tightly and end up breaking a drill. 

(https://lh3.googleusercontent.com/pw/AL9nZEV1eUIX1BFxpr54MW4iO4URaXj7wXk0ZyxN5kpx4qNOno9df-BqTuf2bzZNHxTqgAsv8jrr4fTRlbkW5IMLNmVRF2Z5QM-2jwEFw9GXBZDbmHE9p3j390MrcyOuCI29bK7XzeLZIM1_Qi6-8zfx3pZkZA=w784-h1041-no?authuser=0)

Then I made the counter-bores at each location using a 1/4" 4 flute end mill.  I know the bottom of the hole isn't perfectly flat using this technique, but it's plenty good enough, as long as the head of the screw doesn't protrude from the hole.

(https://lh3.googleusercontent.com/pw/AL9nZEVk9uB93zU7mXwtBevIySOE1xW8w_qb7ZaR94wWSLcn5WmroWatcLOr6YFF8iZENAejtzb5t_aWTbZYPHLgMIhPAEj7fhNJUJccJx8jvKngxxFdJYypsZ2NrmhxsHVa9idW4tBSyT5_qz5ziNFcoPsmtg=w784-h1041-no?authuser=0)

There were 4 additional holes to be drilled and tapped on the front so I again just located each position using xy coordinates on the DRO.  I spot drilled, then drilled tapping size and here I'm tapping using a spring loaded tap follower and a small tap wrench.  Plus I'm using a spiral fluted tap as it's a blind hole and I find the spiral flute taps work well in this situation.  I always try to use a tap follower as these smallish taps were way to easy to break if you're not careful!

(https://lh3.googleusercontent.com/pw/AL9nZEXcJv5mA9XLaKX_9PL9R5UwH5oqcpIvyiDeiib7gLR_sbg2XvVBwubrLUXa1pQ5quHCmFlBiFj5A4H_R-O7dd6li9coqbx-nJH7d6KLDhl1SpkS--Q84O_WyboOfprcMZ5ph-hPV7rGLYOXEwMmtjThXQ=w784-h1041-no?authuser=0)

The next operation was to flip the hopper over and drill the oil access hole on the back side of the hopper.  Again I centered the body using a DTI mounted on the spindle referencing the cylinder liner bore.  Positioned using the DRO, spot drilled, drilled #42 .475" deep.  Shown is putting in a .060 deep counter bore with a 1/4" end mill.  All that went well.  You can also see the thru holes drilled from the front came out in the correction locations on this back side. 

(https://lh3.googleusercontent.com/pw/AL9nZEXKnzYTxliywJFvGiEYvBIhK_rszXUxjpYyYitdOn6b-r8k0v6Lgl2rCQEQ6JYCQXHJvyEmxoV6iF7smOSNtHdEFC9nKNKEdNQW9sLmgIOzlbLBOv_ysaG7aAxBkLKniNvilMv8Y4dCNGrJ2Qy133uOOA=w784-h1041-no?authuser=0)

Now comes the tricky operation of drilling an intersecting hole from the cylinder bore to the hole just created.  This is to create a path for the oil to flow from the drip oiler to the cylinder.  The first issue is locating exactly where to start the hole.  The drawing specifies the location from the front of the hopper, but since I know the OAL, I decided to locate from the back side.  So while the hopper is still oriented with the cylinder hole vertical, I decided to use a boring bar to mark a mark on the ID, indexing from the rear surface and measuring the depth via the quill DRO.

Here I'm locating the surface and setting the quill DRO to zero.

(https://lh3.googleusercontent.com/pw/AL9nZEVkUV_I8VOZF03xpe5Wmd66isKWwbBPPJyDfpFfhWVuOPrEUoyOD54sXTD9ow0VPbJDy910_2cxt5dTk8iP6IfX1o6wZ1Z1R2b7MNYk6dNrdadUP83rPgzUP1Jn0iktkcV1r-TYMoE6hlit3JnJfpC_lQ=w784-h1041-no?authuser=0)

Then I lowered the quill to the spec'd depth, moved the table until the tip of the insert just touched the cylinder hole ID and then lightly scratched a mark at that location.

(https://lh3.googleusercontent.com/pw/AL9nZEXYXLj6RKK0NuxW8bIb3p0XX9100o3RAbappAYjFC6skzUfLavZdWKlMMUQ6h8-nu__9kftZjow6xrMvdlazoDMHXBNWBvD3-UxzO5d5nVxCk9z61mQGPatbdOwtILRUByluDpQz0wgS0ZA9vUcF4obYw=w784-h1041-no?authuser=0)

Next I tilted the hopper to 18 degrees using some angle blocks (angle was suggested on the drawing by Howell) and then visually aligned the center of the end mill to the mark using x movement only.  I didn't move y at all as the part was already located in y from the previous step.  I used an extra long 1/8" end mill to mill a flat surface for the subsequent drilling operation.  This actually went shockingly well but I barely had enough room even with the extended length end mill.

(https://lh3.googleusercontent.com/pw/AL9nZEV4DYAS1OsbGN7Mj3HK299CGdpP-RwB9_0L7_1DD9j2nu9EQW_8pTm6WdJoWxXw3iMBGnln-nGXKQMRMfqmpwY6NucZmnOmSj0a5gy0c2xTgE5X2LwvK8g9u7zh0K-z8sOGEQfBlpe-1sZG2g1dF0WKnA=w784-h1041-no?authuser=0)

Then i center drilled with an extended length center drill.

(https://lh3.googleusercontent.com/pw/AL9nZEVnC_-R_ZKK8fxBeGtXVx8LnP-OX2KUeII3c1h-dS2RAkVtTi7Fe0YZKYvVNNI4w1cTFItRarRIbvRGlUGZNwCNgEKor-9rIj6jj8R2EGmPUE36ltyWdcQfih0MzVZPopghgn1bD1J0_3YI_KOTLXKcmw=w784-h1041-no?authuser=0)

And finally drilled the intersecting hole with a #42 aircraft drill.  Luckily I'm located near Wichita, KS so aircraft drills are easy to find here!  I could feel when the drill broke thru into the previously drilled hole. 

(https://lh3.googleusercontent.com/pw/AL9nZEUUV3du1uxN3ezTFG1P-8oQWx9KYhgAcSL6uXmVxA9IROEYqeY7gE0P4fHhWhJx0l_QjT0WVhHiWwKjIVarDHB3M2BSctZ6I707o76--YkTa85iPim1GPa7xfDYhBmdsHqd511LvHEugyjYaLCVsOzX9g=w784-h1041-no?authuser=0)

Here's a pretty good picture of the two holes after both operations were completed.

(https://lh3.googleusercontent.com/pw/AL9nZEU18XxzDPN8WN8g2qN6BE1blavv7bAfEmxJioYpGyWjDsfkZZWvfApeYORLkOVqcVR-HTELKY9Mp2IlPac1D-mCsxH7YIEirccvMnrRi2iwIU2OAmuw6yrI_EtgmWtqmQq41kAX4uDgZthdM9IGhkXDtw=w784-h1041-no?authuser=0)

You might reasonably ask, are you completely sure have intersecting holes here?   We'll there's  a quick and easy way to prove that!  I'm just shining a light thru hole drilled through the face and observing the light that appears at the hole in the cylinder bore ID.  The camera actually shows it more clearly than I could see it with the naked eye. 

(https://lh3.googleusercontent.com/pw/AL9nZEVSetgqg-KFFGsLcVgCRB3DUxS5CTUaFjILQh3aFHbRzrQKL8fZ0xdS-CQ6A6e5s8tV0AEHPq1r_dgl3V-FwxS_tiCaU-wbdoqkMeCP-B7EO_i3RsXMDnsf4-qTVzU8ZyqF6oSptW0RybxSMAfi-O3Oxg=w784-h1041-no?authuser=0)

So the next operation was to round the bottom of the hopper.  I'll comment more after the pix, but I don't think that this was the best way to do this.

I used my 6" rotary table and made an alignment system consisting of a small steel pin that fit in the rotary table bore on one end with the other end fitting into an Al rod machined to fit the hopper cylinder bore as closely as possible. 

(https://lh3.googleusercontent.com/pw/AL9nZEW2XOqHJE9eyeb9OpQ_r2ev00zw8T3EZEIcqWSZziikhM8726aFNJr_dTNoHR1nNQjOMsx4kdruEFbppVna-alFl1GP9vTI9v84_8WOqrvtIgYTTbOJJmZjk5emlOvJwcAIhzbxf285aSEEZ-7iibM8Dw=w784-h1041-no?authuser=0)

I centered the rotary table under the spindle and secured the hopper to the RT using the alignment jig I made and 2 step clamps.  I offset the mill table in y only and walked in with a 1/2" extended length end mill.  As you'll note, this wasn't long enough to completely round the bottom. 

(https://lh3.googleusercontent.com/pw/AL9nZEXxMauMDUb0M8TYyeGBcGzLk1KeOLzxebUZCNIupk5BnKrICXG4SKx_Q5KnwD4El9yBGc61FLgq-mCIkGKgW2RBqJVJ4RjOYQoK3oSgIfVQF5SxMVeq-uZ79ILNOc_OvoGTjjdBP8eE9iF74sPDvVV9Fw=w784-h1041-no?authuser=0)

So I turned the hopper over and started the rounding operation from the other end.  You can see in the pix how I progressed the cut inward using y only and swinging the part around the cylinder axis.  I took pretty light climb cuts as this seemed to keep the chatter to a minimum and gave the best surface finish.

(https://lh3.googleusercontent.com/pw/AL9nZEWEOp_jZUpeIGG7q-Gc5pSmFeA3TJl2H1T00q8QUC_aTQ94TeShHcmBmIVpr90U5LIoDotWdI_4Dc6xEYVABhwb6Z-fPteu6Lka2VVsNHM2jtUxtaqj6RXqg0fcThiyB0A7Odcu48KpVOqwPL7iPheRsw=w784-h1041-no?authuser=0)

And here's the completed part on the drawing.  If you look closely you'll start to see the problem.  It turns out to be very difficult to start and stop the rotation of the part exactly in the correct position so that the cut progresses neither too little or too much.  Plus even though it's close, you can see the difference between the operations from each end.  There's  a little difference in position from each side and each ends up at a slightly difference place.  My solution is going to be body putty followed by sanding and painting!   

(https://lh3.googleusercontent.com/pw/AL9nZEVxfTWOkMF61GeMDYCg9uBpEE8ijet5_DW4MNw7yYe8PHr1qgfA6n_rflqAhmNjNZWiol2NuFldJKrb0ooLs2isdpmOljDje07Li2PLEq5Eb73qAxmsEnj535qUW6ejCE7YDk__tX-EgdJmQFPK3oNoPQ=w784-h1041-no?authuser=0)

So having done it this way, what would I do differently the next time?  I think that I should have oriented the RT and the hopper so it rotated around the horizontal axis.  Then I would have lowered the spindle and made a series of cuts moving in x and rotating between each cut.  That way there would have been no swapping of ends and I'm of the opinion that it would have been much easier to judge where to start and stop the rotation.  And as an added bonus, i think the cuts would have been smoother with less chatter, since the end of the EM would be engaged vs a long length of the flutes.  If anyone has any suggestions, please feel free to comment.  I'd love to do better next time. 

And the last operation on this part was to round over the edges of the top and ends.  The Howell drawings indicate a .125" radius on the top and a .093 radius down the sides.  I decided to simplify that a bit and use a .125" radius rounding over end mill for all the corners.  Here I'm rounding over the rear surfaces.  I did practice quite a bit on some scrap before doing the actual part.  What I found was that you either have to make some cuts to determine exactly where the radius you're creating will be located at or you have to come up with a process.  What i ended up doing was to look up the nose diameter of the end mill and used that number to determine when that nose would just contact the work.  Then prior to making a cut, I'd move the cutter until it was almost off the edge of the work and lower it until it just scratched the surface of the work.  Then to make the cut, whether in one pass or multiple passes, simply leave the cutter at the previously determined depth and move in x or y as necessary to get to the full depth of the cut.  I also found that climb milling gave a massively better finish than conventional milling. 

(https://lh3.googleusercontent.com/pw/AL9nZEVcaveGGLwOYoYWk3QwTfyurq2tOswSroaFubJr8xtfEU6LSxapWlY7iMMpCBWRU7nQ6-ET3cSlF9fCEvcUuZWyLwy3qrvmgOBYXnxrT4z7fX2pu9bXR68tH5aBbIt11p7KWM6ndv-SiAu_n-FvU3doDA=w784-h1041-no?authuser=0)

And at last, here's the hopper completely finished, well except for securing the top in place and doing the body work on it.  But that won't happen until everything is assembled and tested.  This part is a LOT of work and the further I got into it, the more nervous I got that I'd scrap it and have to start over.  Anyway, it's a relief to get that done!

(https://lh3.googleusercontent.com/pw/AL9nZEXPD8G9-d9_CkNbtwp-JuD_Dc2XVTHsMoqyYPDgn8D5XwAOAQ6qsVI7wSShgyI5HDLD2pX4TGw8VCH0xVKttbJgO7QOinK4XMfpsl9Bzp3Msrf3KBF3laEQxetH52xjcAntQol8bmvusLh7nDS2DmAUIQ=w784-h1041-no?authuser=0)

All for now.

Enjoy!

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: RReid on September 22, 2022, 01:26:44 AM
That's a heck of a hopper, Mike. Nice job! I think I would agree with your alternate approach for doing the rounding "next time".
Title: Re: Farm Boy #876 - Mike's Build
Post by: cnr6400 on September 22, 2022, 02:55:12 AM
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
Title: Re: Farm Boy #876 - Mike's Build
Post by: Kim on September 22, 2022, 03:01:05 AM
Wow!  That is some fine whittling there!  Beautiful work  :ThumbsUp: :popcorn:

Kim
Title: Re: Farm Boy #876 - Mike's Build
Post by: Admiral_dk on September 22, 2022, 07:32:59 AM
Great descriptions and result  :praise2:

Looking forward to see the rest of the journey  :cheers:

Per
Title: Re: Farm Boy #876 - Mike's Build
Post by: Krypto on September 23, 2022, 03:18:02 AM
Looking forward to this build!
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 24, 2022, 09:21:26 PM
First, thanks to all that are watching this build log and making comments.  They are always appreciated, and of course I appreciate any good tips or techniques!

So, on to the next part on this build, the front frame.   

In one of the previous posts, I'd already squared up and brought to size a chuck of Al for this part, plus on the lathe, I'd bored the hole thru the entire block and put the counter bore on the back side, all as per JE Howell's drawings.  The next step in my planned OoO (order of operations) was to create the profile(s) as viewed from the side.  I do all the work using my DRO for positioning, but because this was a fairly complicated series of operations, I blued up one side of the part and marked it out just as a reference.  That way I could double check myself to make sure I wasn't about to make a tragic mistake. 

Here's the part marked out and ready to go into the mill.

(https://lh3.googleusercontent.com/pw/AL9nZEX0drv1o3cEDolon1iKLoK0hwT53_5fWoJ87B-qgizQLIpAUzrEMz5LcV7Q-Xk1WgiHjeRz4zxXjzleBL5MPHMd9oquYZIZcvi_hTW-b21mRtCbaAB2wJFHsred53n5IFD3EJxQA5RxSklK2R1smh98YA=w1224-h922-no?authuser=0)

That arc on the upper right surface doesn't actually go all the way to the back of the part, so i first milled away that straight portio with the result as show in this pix.

(https://lh3.googleusercontent.com/pw/AL9nZEWW0r3_5RSKb9zR_MzJD_vZtwqhl6Lw054nL3_FiSdFteJWhCnYGVAIRvaLQmXqUjeG4BnyFJjCzYnHqthtJJUvUrkCONK433ROiDG53bimCm44mQI_gqbENlR-HEbnmUIin9nHekJbZUYW5Eapw5BbWg=w784-h1041-no?authuser=0)

Then back in the mill vise to chew away most the material that needed to be removed in the upper right area.  I stayed well short of the marking lines at this stage.  That's a 1/2" roughing end mill and it does chew away Al fast!

(https://lh3.googleusercontent.com/pw/AL9nZEXFl9bJTxGvHzN0Cb2ctCF_s9-SK2MG2t4IJHouTcYBqFechYIaBgqbhmnnXjynvQc9OW6scxiDboZChHhNqiha9qdvRwhuuZ8BJZk_zqoOI7LefGDVpGfvzvk4TgpRd1f6woXjIYWGNnESbh1UFt8z2Q=w784-h1041-no?authuser=0)

Next I positioned the mill spindle over the center of the arc which is actually not on the surface of the part.  Then I took repeated passes advancing the boring head between each pass. 

(https://lh3.googleusercontent.com/pw/AL9nZEWh0HmBcMEKxJd_vUS2Ig2be8HzeNMMPcIfszn7G5pKjbB8VBoD1I7nxL4paCTKuzjeYOCqYTfvsaXukU9H3qSVqaZWQa3ymnm7bnl1Ov4RHuJ0zIkuXW0YJpbOAdNdv9Y-3Jby7B-G03w2SnmRjVQt1Q=w784-h1041-no?authuser=0)

And in not much time at all, I ended up with what you see in the pix.  I kept progressing the boring operation until I just met the layout line at the front and the previously milled away horizontal surface at the rear.  A bit of measurement also confirmed that the radius achieved was as per the drawing.  How can also see how this feature intersects the previously bored hole and counter bore to create a good portion of the rear of the part. 

(https://lh3.googleusercontent.com/pw/AL9nZEWNs3kTJeY36ZJHV2gqv2rf8wjNhU_e3MfYWlFqBTCrFpdn72mTSmiVeBa7JrQge1sT6vpQg9KXOybU3556PXx7zjsQ8wD7RxU8OPHZ0_d3YROiuqTnMJYoXGmITxY8qlfLibXuUHcx5b2GgOlispsaqw=w784-h1041-no?authuser=0)

Then back into the mill vise.  I didn't show the operation but i put the mill spindle over the center of the arc that forms the front radius.   Then I drilled thru in steps and ended with a 1" drill.  Then i switched to the boring head and progressed the cut until that arc being cut met the front and bottom layout lines.  I also confirmed the dimensions by measuring. 

(https://lh3.googleusercontent.com/pw/AL9nZEUprdbQ6YW83JI7_7QpkjTTxI8oos2NIF3q4vk41AHJrj0LnIU5YgZ1Z5hNnLoeVGuV-sxutRc8zyRLY4AkRCIkjlpiXs0KfbotOMSjaV9t-a3KlAeynjOhioLa5EJSPZW6l5PrKaGs8BHYTtLoY_oiNw=w784-h1041-no?authuser=0)

Next I reoriented the part in the mill vise and started chewing away everything that didn't look like the front frame.  That roughing end mill works fast so this didn't take long at all.  You can see how this operations is intersecting the previously bored hole. 

(https://lh3.googleusercontent.com/pw/AL9nZEWpS_E7A2k653_Kyaj6f98Q0oUo3lwzDDzWphWNV21p5rkY39Ky1wyZc02jOKVyGtpyEbUSOaNHP2D8TYH1KkV9g4PlFMaJRLXYP9esll8tJtyt-nUiQEyOr_ROfBMIcKxUwo4sblY7mNAn0PQ0eLfOkQ=w784-h1041-no?authuser=0)

Then after I got most of the material removed I switched to a convention 1/2" end mill and brought the piece to dimension. 

(https://lh3.googleusercontent.com/pw/AL9nZEUndPj6z76u934M4w4Fp0KjO7XgnVzxi7imaqN_nPnrwrF1Xyd2VuiGwpS27SgaPJPnqQpOnnLoA3IY0GRVggfJ1k1uNt-Rd-x7KT2zz0YB1h246jhh7eEFoaIO0nyvRI9OJtBZZCx_ihtOy-E4eolaGw=w784-h1041-no?authuser=0)

There was also a bit more material to remove on the base of the part so i did that with the same end mill, being careful to try to blend this cut and the previous cut as closely as possible to the arc.

(https://lh3.googleusercontent.com/pw/AL9nZEXwZlFDJuuWqTuP98WWSwOvjTejQX-AjT5bPdCRTMY_oqdBDacpfvNlJaDA0WToX5Ti-XMxVe5RMuPifzR08-qxqJX4JaCboysinCY5zQoYuo9wO5RR1l0dpdwVAEBsGt51PBMXG8zJVB-QjlLZGrl8CA=w784-h1041-no?authuser=0)

And here's a couple of pix of what the part looks like at this stage of the operations.

(https://lh3.googleusercontent.com/pw/AL9nZEW3Ojj9NzTvtgst4JNxz9kKTaErU08J2vE8LMwhBfuFadUya-8WFpZWW475fz9_DpVfIggmyLolLq9kn26pAyz9rTNF8Ss-GIWYL9sLU2JJIM58I55F1xfl4umbd69olh5iFUQHx4_o2XIW5V28Rq-ZXg=w784-h1041-no?authuser=0)

and

(https://lh3.googleusercontent.com/pw/AL9nZEWnMA9iCnDVOYlc99SgoDxIXHpzODHBu8M1tHPTfFDxs1U_wtYXb0Wo0NPj0ifg9iQgDTqyPNwEiIxrY0Ybp99nv6rGUZsW6vX3gof6L1ZYLI2XqO4sshwJk4Tse_ZHXUCfrwB2AYbbpPpxM3IDBtChYQ=w784-h1041-no?authuser=0)

Back into the mill vise in yet another orientation.  This time I milled away the material in order to form the feature that will become the joint between the this front frame and the rear frame.

(https://lh3.googleusercontent.com/pw/AL9nZEWo2Ypvy9d0spomkq4FnOTznHnDpAqXdoQsl67hK1_xegAbmUI-LumNHxEV1IE2J4R0wVsHIu29qVlhUl8VIeMKc4BuF7TbnH35Wll-gfm16O90-1nxYE1uKcCe94MNdp09iTqRcmt3UOhtLupkCSlO0Q=w784-h1041-no?authuser=0)

Next the rest of the material that needed to be removed was done.  Again I started with the 1/2" roughing end mill as shown.

(https://lh3.googleusercontent.com/pw/AL9nZEUZRHZWhX-xmVSOJ3jt1Ji2QZrJ7bpOfgICQETn-l0qbZmlmpWSPGSTTx0mVTOoagLJfCDrFykn_PuWqOzan_hxR3HZeiA3JdXBQIsZyIIsive_T6Q-ActluH9TbGQElwXWnmDTMrN8R2dFU7XC1nVsNw=w784-h1041-no?authuser=0)

Then i finished it with a conventional 4 flute end mill.

(https://lh3.googleusercontent.com/pw/AL9nZEX2QBoDTDHqaGkZnAWw-g3eq1UXr2OP0QdKlUhrbSktvH4NmfU-PorLM2s0sAn0EjgCMaEVMYTpgNfA74mi43SPI9R-sPG_FYSf9kWQot6DfacyqDbLQ7CUVUqFivxQcRCKzkTAKvkdFhnIY5C6RjPKNA=w784-h1041-no?authuser=0)

And here's the part laid on the drawing.  I've shown it as compared with the drawing's isometric view.  So far so good!

(https://lh3.googleusercontent.com/pw/AL9nZEWwRnotoQ7n8J19LBkqGUr3B1yiVp8mA-eUAkLV-4xKJtqa58-6CEMc-fs1mD-TX2aFjyP4qoYmxxqCy6RT0tpD4pTVUMeLyE-AZkCfQN9WgECBRrmvLDbPmEfmnrQpM393hRk2VnXA_zKpVnHFfZCFog=w784-h1041-no?authuser=0)

Back into the mill vise yet again, this time oriented to drill/tap for the drip oiler.  That's a PM Research oiler that's threaded 3/16-40  in what they call their 'UST' thread.  I ended threading the hole 3/16-40 METP, but I've also noted that you thread it 10-40 and that will also work.  I always do use some thread compound prior to final assembly and I've not any problems with leaking either way.

(https://lh3.googleusercontent.com/pw/AL9nZEW2w1rCdExj0yyEwumGjA0bOiiOvHyDA2WQ164urVufP_oCqu2PKGk9bBCnfSGmB6e2PGKlZMaDgC6YcuYgeWA0r1qv1rx0RtY-4J14v29mOrrt4gTCRLr_6RUZjcP-cHQp0X8lgehsX4FlGwnhjOPokQ=w784-h1041-no?authuser=0)

Orienting in the mill vise again and checking to make sure that the part is straight in the vise.

(https://lh3.googleusercontent.com/pw/AL9nZEUMUOchUL7a8IRFteTkqi9dhFeWqNhfD67HwAfsTzhNI3hSp-HtDyIZ_6m8j36IJnQhtaFSwU76aJSHcMAQQ-J-En1XoRWU4n1BjJgSBIX6khLJ8WNOYh1faBgL6KW5GexssQs-LKb0zQRFliaBYCTgQw=w784-h1041-no?authuser=0)

Then centering the spindle over the cylinder hole and setting the DRO to 0/0.

(https://lh3.googleusercontent.com/pw/AL9nZEVH31L8p9pg3rUARgdeGh6G5C0DeMp2jh7iorPhgJYFBvrrRkBr6jVBLBh3SucSmxCuUKt_6Jdb0nLW64YG8Ohn9svsjHacTRjYbyCeTcOpYjbWhlFpoL05kcVhxUkQ8wQBVSGMQxWaWASV2vWPqWF5Cw=w784-h1041-no?authuser=0)

Next drill and tapping 3 holes for 6-32 and drilling a 4th hole to provide a passage for oil from the drip oiler eventually thru to the cylinder liner. 

(https://lh3.googleusercontent.com/pw/AL9nZEU2w76GrsWpkv7IF8nWZE-6OV5_gnlW2dwS1vNg4uWepTokIRfjtfsb7k_jGaa6Trfolw-k3BB3v9CwnZO8cW67pDrHEjQkdWPywM09QPEYgizBEhNWG34R7Ix_MVBfTZf44nywdQ0fK6_1iMQAZFg1Rg=w784-h1041-no?authuser=0)

Next tragedy struck.  I was overconfident and entirely too aggressive trying to tap the 4 2-56 holes in the side of the part.  Of course I managed to snap off the tap on the right off on the very last hole!

(https://lh3.googleusercontent.com/pw/AL9nZEUBORKEm9kdZaolNGSflQqO1m4Qtft1NOc4PCXZMPLdHk9N4hrQZkA97pCAuR8mjhHRHp8_D8kFMkCUIliMOx4FDQ034mhdPqYn2Il-5yz7k926m82yov997Q6GZD4Jwm4cJ5Y31nuKrpEM_ShGow_RmA=w784-h1041-no?authuser=0)

And here's the remaining bit of the tap buried in the Al. 

(https://lh3.googleusercontent.com/pw/AL9nZEU43glb4lfZCvlN2yRLuvIHXeq5975492Ysu4-wgmNzklckILnyqI8ukRmj7XKVEc21bLseEQcDFw78C4yu4W_GOmFiziPufVDXGHqmPJ1dpLEZBnMNsAKQr33zcFKsGQ2UfjrhocpziwgpwfHKcUwqZA=w784-h1041-no?authuser=0)

After some weeping and gnashing of teeth, I decided that there's no way that I was going to remake this entire part, so I was determined to at least attempt a repair.  I was pretty convinced that there was no way any sort of removal process was going to work given that there was nothing above the surface, I decided to attempt to mill it out.  So I went after it with a 4 flute 1/8" carbide end mill and slowly progressed it and in fairly short order, I had a clean 1/8" hole through the part. 

(https://lh3.googleusercontent.com/pw/AL9nZEUhWnpdpApnKuiig1WDTmVbWL4zboa5qvFQIcVSONkSPOqEPjbGy_fzk-DaPgoEl3jwj0N-Yik4RWeNg0HHP0ybY09nmkhuH0YzPoo-tzr0fO5buPTbp_ySSmRPMUa31LG4S2nYEco48TnoGr2NKSOCow=w784-h1041-no?authuser=0)

Then I enlarged the hole to .1875" with a larger end mill as shown.

(https://lh3.googleusercontent.com/pw/AL9nZEURN1wOFS3DjvLuYSW5nByg2mWqHWOQAF9Y2Yk084n2G9WtolrJvoGM-DHMhU2WqrIH-3qczdgZTnHqIFb2U3Ru2XSayPGNyCH-cnKBDZQOT1-vHLiaNxLAChay8ol7xUeZ9wGJIwGsRcwxYgOAjlz-HA=w784-h1041-no?authuser=0)

I cut off a short plug of 3/16" Al rod and put a very slight chamfer on the leading edge of it just so it would start into the hole.  I applied some Loctite 638 and pressed it into place using a 1/4" pin in the drill chuck, using the quill downfeed lever. 

(https://lh3.googleusercontent.com/pw/AL9nZEXGPkZ3DZ8cmtYooG52qGypEFu5awv-0BDK3EG3BEkOgLYOMyyWuAromznKYynealXkQtM_U0jxTZlz8NQpb1hqgKr7v85mka1_lICZfydRhPZ5JRRRTlKh4E_jpEwF2zuzZ6f6vZFFJ1uuQAdEHxnsUA=w784-h1041-no?authuser=0)

And here's what it looked like after pressing into place and letting it cure overnight.

(https://lh3.googleusercontent.com/pw/AL9nZEWT4_F7U-1by_o-nmytkJepAW2UN1ywNqHt1wsKYQnqYBbIHsVy1Jubs230erzVL5DzysEQyfNN3_jJLtsRs6gC9kF6L32iGVKrzh4reEpd1eblUhHzSNMdRpvMoOk9uGH0DBccVp-F2hmDlSBzPzxvlw=w784-h1041-no?authuser=0)

This time, being quite careful, I drilled and tapped the repaired hole.  This time successfully!  I used a spring loaded tap follower and a very small tap wrench handle this time. 

(https://lh3.googleusercontent.com/pw/AL9nZEWyka6R7ziH1zHIjiqatenA0Vvga-Cvv5RtAp9WnWOQ3spOcvEHqno8t6dz28KVtUyihSf4gHsJzcwffqB5yOkzSoLqboM_d66RtH1GbaLNU4u5Kqm6BIiAzqD6EY-VEDhREVt-Jbn3NmNSL__Xes5IWg=w784-h1041-no?authuser=0)

And here's the part with all the holes drilled and tapped, with the exception of the holes that will be added where the front and rear frames will be joined at, but those come later.  You can see the repaired hole with the plug, but that will be hidden after painting and assembly. 

(https://lh3.googleusercontent.com/pw/AL9nZEUueh6fMRXhjo_F92q1OaGVnPX430JiLYv69UL2lM7yeebi9NWBReV2k_6oQL3aHFe-5ie85ed0gy1aLqiW1GA84lvaidAw5dTfGqYCtwJJEQOP0cBBZhk0HSve4x1IhAVCCDh2G09BFz6IwnP9SMiGkg=w784-h1041-no?authuser=0)

Next I rounded the top using the same setup with the rotary table as I did for the water hopper.  I think that this worked better as i could more easily tell where to begin and end the rotation. 

(https://lh3.googleusercontent.com/pw/AL9nZEXxgM6aObkjqc2ToLy2w-peHDcygtNfun39MwPnrD7U1AihpHuhvGlUte52PQ_epVS0wlN4ASvnfSDr33XLei-5-4wMW2fAHRyNVkfQOS5V_KCCPWN0qXO6ssh3pwC6JhL1vnRLtUKNDXLa10MzabARLQ=w784-h1041-no?authuser=0)

And here's the part on the drawing after the operation to round the top was completed.

(https://lh3.googleusercontent.com/pw/AL9nZEWRjM6BVh5U5-8NoTj6RjvVuU94EdHRWqUoUnhMQDGPD4gbNwT4rUuIx93QqZXhWUfljCmTWcRY0vOoDkiKk0KqF6GlE3HaTtkPst4bAheM47rw_flNjesu1IC5e1Hqis7s3B-9dEIQNsv8jI_yhjsKgg=w784-h1041-no?authuser=0)

And the very last operation was to round the front corners of the base off using a rounding over end mill.  This was a pretty simple thing, but I think it adds to the appearance.

(https://lh3.googleusercontent.com/pw/AL9nZEX8UaEvHRoJRK-fela60Sa_ugsmfy2m8W5GTmGtwyBN5ZXPht2fPM8GWoAFhYrTqTOltJ4TdPiyGUoN1QC2Czc3SxR8q4cJZgBcxZS3LdR4Qm_txOg7ewYZ08TuX8DTi-cwxVUd1gboCgQP_3GIjfPp1g=w784-h1041-no?authuser=0)

And this part is now entirely done!   This part really turned out to be much easier than I originally though it might be.  There are a a LOT of different operations and setups, but none of them turn out to be that difficult.

I hope this was entertaining and at least a bit helpful!

Enjoy!

Mike


Title: Re: Farm Boy #876 - Mike's Build
Post by: Kim on September 24, 2022, 10:48:52 PM
Very interesting operation to make that complex part!   :popcorn:

Sorry to hear about the broken tap.  We've all been there.  You made an excellent recovery from that though!  Well done!

Kim
Title: Re: Farm Boy #876 - Mike's Build
Post by: cnr6400 on September 25, 2022, 12:57:05 AM
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
Title: Re: Farm Boy #876 - Mike's Build
Post by: Roger B on September 25, 2022, 08:16:06 AM
Excellent progress and a good save on the broken tap  :praise2:  :ThumbsUp:

What insert lathe tooling are you using?
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 25, 2022, 03:35:31 PM
Excellent progress and a good save on the broken tap  :praise2:  :ThumbsUp:

What insert lathe tooling are you using?

Roger, I'll answer in general terms with ANSI designations.  There are ANSI to ISO lookup tables if you prefer that designation.

I tend to mostly use the 'C' shape which is the 80 degree diamond shape.  The advantage is that they're very common and they can both turn and face without reorientation.  I also have mostly 5/8" tool holders so I tend to purchase the 3/8" inscribed circle inserts.

With that out of the way for Al I use CCGX-32.51 (sometimes indicated as CCGT) inserts.  That's a dead sharp, uncoated, highly polished, high positive rake chipbreaker insert.  It cuts Al like butter.  You can also use it for steel but it's not nearly as tough as a specific insert for use on steel or cast iron.

For steel, I use CCMT-32.52 inserts.  These are tougher than the Al specific inserts and I use them on cast iron, drill rod, and any other ferrous metal that I'm turning.  There are a wide variety of coatings and chipbreaker styles so you'll need to do a bit of research to find one that you'll like. 

For parting and grooving, I almost always use 2mm wide carbide insert designed as ZTBD02002-MM.  That's from ZZC-USA but that same insert is available from other vendors.  I also have the 3mm wide version and a 3mm round nose insert for creating small radii.  With the 2mm insert I can part off easily at almost any speed I choose and can also create wide grooves as the insert will cut when moved sideways, as long as you don't try to take too much off at once!

I also have a few inserts in the 21.51 size in both the 80 degree diamond shape and the triangle shape for use with small boring bars. 

There are of course, an almost infinite number of vendors for inserts.  But since I don't want to spend a fortune, I generally purchase either ZCC-USA and/or Korloy, both of which Shars sells.  Shars is reliable and you'll get what you ordered.  Cost is around $5/insert.  These days I tend to purchase from Shars as their price is barely higher than Ebay and you'll get exactly what you order. 

You can also try Ebay especially for Korloy where you can typically purchase a package of 10 inserts for about $40 with free shipping.  But on Ebay be cautious who you're buying from as there's almost no guarantee that you're getting what you think you're buying.  Inspect carefully upon receipt.

I do also use some HSS that I grind to whatever I need.  But I tend to use HSS rarely as the carbide inserts are so cheap these days and they work so well and last a very long time.  If I buy another couple of packs of qty 10 inserts, I doubt I'd use them all up before I'm dead and gone.

Hopefully the above is useful to you.

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 26, 2022, 02:55:26 AM
Next up is the rear frame.  I thought that this was going to be the easiest of the 3 major frame components, but it turned out to be the hardest by far.  Read the following and weep  :'(

The first feature that I decided to do was the rear portion of the frame.  I started by blueing the stock up and doing a basic layout.  Then I drilled thru right at the center of the radius that forms the junction between the bottom of the part and the back angled part.  Since I modeled this I had the xy coordinates positioned the hole with the DRO.

(https://lh3.googleusercontent.com/pw/AL9nZEXdyrMh0ncv_Xf9poNXvJodRqCbu9AHiRFcOKlQlAmtZs2cmXr8vXvrmSVQ_Gh8Kq7WATEk8LFZLAftS_E-yHrlEewyJSIfJNtfXy1LZaF7h1UGAbYGETQM3DEfVQ34w7qskKW89q7ur7hJmirHPmLI8Q=w784-h1041-no?authuser=0)

Next the part was repositioned  as shown and i  chewed away at the material that needed to be removed from the back.  I first used a 1/2" roughing end mill.  You'll note that i stayed clear of the layout lines at this point.

(https://lh3.googleusercontent.com/pw/AL9nZEWyNdJgm6eJlVppLyL5PgNO-CSU00-RQWzc2cQ_k72Nw6S0Mrtt5r8oxoSGUGMRSXnFX_hKLyrCNA2OMFnZJNm67kfUL_j46zF8WSWAHQUd--gmdfPBgD3GPAh706BypUWofzxSMbk6O3vTzXrsByRrSw=w784-h1041-no?authuser=0)

Then I switched to a conventional 4 flute end mill and brought the bottom feature to dimension and tried to blend that portion to the radius as best i could.

(https://lh3.googleusercontent.com/pw/AL9nZEVO7dTGxN1TqKEv21tDMUKyD5AhXaaUnUeOnTfe1oHbd-SA7oPGgWZlfOzKJeEjIKaRXe-cFGESGVy2r2bKTr3nqGK9fUJYixPFXT9aiGC3BPO4jms6VcAOqFqFsEHAT1kO_5rM_1uljDMZGaYXj1YfFw=w784-h1041-no?authuser=0)

Repositioned the part again and cleaned up the rear surface with a 1/2" end mill.  I used an 8 degree angle block to set the part tot the specified angle from the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEVRLAwI-N2sojLxVukB3HOBzVnys90f-qJyAwIQdffD_fJg90bAvQrq3wRxRTvCIBuaNBoV4Z4fZeJ_mCOblw2mJbmlErRi8zQ-DeW0c_m7fTGRVoRpLO6gStqZ57oblr6QMeb187o2Vh81dEIYP_5ttw=w784-h1041-no?authuser=0)

And here's the part on the drawing so you can see how it compares at this point to the isometric view.

(https://lh3.googleusercontent.com/pw/AL9nZEVKvQ-COVyJR5cbRboiPxfPsnrU77zr7g-a99z05h0iZKineJzPmKa4GKic1yHbtwriZT-1HAEtZA75RwqElnvsEaVZWxI1ts71vLTfHIEqy7FcdluZ-HRP3gEYyucis2hYmA6Tv091lZrPig7-qdu01Q=w784-h1041-no?authuser=0)

Repositioned the part yet again in the mill vise and chewed away most but not all of the material that needed to be removed from the interior of the part.  In particular I was careful to stay away from the rear of the part as that will need to be cut away at an angle. 

(https://lh3.googleusercontent.com/pw/AL9nZEX4ggUra1zg6-Y7yLM6DxZolq9K9aLNkMqGl-CIf0vWOaczcYSsQJ33CqHKwUuouz7s61gyQIPO-ikqfSb4wkaluHzG3v3vj-w5G5FplIxHo1yQ26Jw1fu55de61Vv_cfq_9k1NNot1FrKRfsmJBHY34Q=w784-h1041-no?authuser=0)

And here's the part with most of the material from the interior removed.

(https://lh3.googleusercontent.com/pw/AL9nZEV7lwX_-jt-tKjF2myXAA8QWysf3DslLqRVSjMjzm550exzOU4lDwDyf1IZ_IUjY37n2Zq3zURyRqGrLv6UgC9sCFBKRPmNJskkexbOMIjuFWrM32APG0YZO1Fwsq3PO8ywhuHlJ-LjVivQ22-U5uQZCw=w784-h1041-no?authuser=0)

Since there's a radius called for in the bottom corners, I decided to plunge in as shown in order to create those radii.  And then clean up the remaining material on the bottom and sides.  I thought that this might eliminate the inevitable chatter when trying to shove an end mill into a corner.

(https://lh3.googleusercontent.com/pw/AL9nZEX0Nl-aT7UeISf3i386Y-lZNcsOI9Pf-OwPiWvUwWktskSebfH1X2pQSRhf32tj-2J83fLYCCgS0HW-6hWlxMv5M3YGqKtMip876yTM2aM1aP5kW3SVE0QtTDWrUBQel4v89YrBaKw6uUFlql7L7_bu2A=w784-h1041-no?authuser=0)

Then I reoriented the part in the mill vise and used a 4 flute end mill to bring the bottom and sides to dimension. 

(https://lh3.googleusercontent.com/pw/AL9nZEXMC0EovBm7B6ISsCSJPcGPYm_5jX10OCHahUWA3irjXZqPXqrAyKRN4VRPxY3lC0o4CCqrdhM7SgcA-6PFpn0t_6kBaFC2sjxSi0GWFNfxVrx1D5r_l0ZXJg2b_7oxba0SqRItrwd4a2dtKpA97QA1TQ=w784-h1041-no?authuser=0)

In this pix you'll see the start of where I went wrong.  I thought I had calculated the depth of the plunge of the end mill when I formed the radii in the corners so that when the back was cut at an angle, everything would blend together smoothly.  I was wrong!

(https://lh3.googleusercontent.com/pw/AL9nZEVr7TO9e72rDQE6kr-I_Tv88bf7EtbMBYMmbDeryv-DGw-zSTQp66-Cspk8lzDsOnnT-sJXxUww42NrQ0WEoQ7yRE33wZVWIN_8i1Z522XkxZQlO8T8T-H1aDPiC96sZQQoJSJ3bgW1XZ2AVpyvP7UR2w=w784-h1041-no?authuser=0)

The part is reoriented in the mill vise as shown.  I put an 8 degree angle block under the part to match the angle previously formed on the back.  The idea was that this ball end mill would remove the material on the interior back and would blend the edges and corners together. 

(https://lh3.googleusercontent.com/pw/AL9nZEVii0Kak3KqRmcSWvnBWOpjvChYAg517fiJ3LP2fFgcJ-7RTL3dKsbj_4AaWvKpqn32r4JNI2hU96E6zP2aKjDUMdRO7rHS9o9XnMEOow8VXkPCUL4IfDZ-qN6nl0XN70pM-bWIumlY7hjCzOQ-VSshxA=w784-h1041-no?authuser=0)

You can see what actually happened.  Somehow I plunged in too deeply and I simply couldn't clean up the interior rear corners.

(https://lh3.googleusercontent.com/pw/AL9nZEUCUc0dpqpVJsm4J41LCK11SwM88oWKOq-ItzIMEEDMjmDKc37nCg4gDn4Rm8NVUB1A8HswJ6fCKyUgW-kQbifZ2hrkrA7249UJdKHZgX8ZEX7jiE2GwqRytATk47bnAWLlPZxQ4AfnHJE9qj05Fmh9qg=w784-h1041-no?authuser=0)

After crying in my beer, I decided that there was nothing to do but proceed.  Here I've reoriented the part 8 degrees from vertical in preparation for creating the 1/2 round opening at the rear of the part.  Note that this radius doesn't start at the top surface but about 1/2" lower, but interestingly the center of the radius is at the top surface.  I noted at least one other builder missed this and had to notch out the back to clear the connecting rod when it rotates.  Here I've found the centerline in y but I'm visually lining up in x as there was really no other surface to reference from. 

(https://lh3.googleusercontent.com/pw/AL9nZEV1uG4z-ajx7-qeBHUxLGNDmeQC4zKJEPrcREaePelQRvMjOId1QLkgWSrCFDdGwlDowuHV4rheZfXbnKhXpEN7uieVx5AkLXhAJuKBgAvQ4yn-ToBrJ4oJ17F89bJVOKHxadxRw5k3W6ZNRG8D2xDapA=w784-h1041-no?authuser=0)

Then I used my boring head to advance the cut until I had the radius formed as per the drawing.  That all went well.

(https://lh3.googleusercontent.com/pw/AL9nZEWDN36vrv0T2Av97BcQi6U-BtO1CcFpZSSXBllUzI73sieYgKybUgYE1RTIE7e9ae-sdSjna7t05E5315uWHO_N3eMniHuoUBYtpGdYrBRZC1VikdIBpwWNh-Iqa-R-Hop2B7kOeQXZ1ncyo8pBGin9qQ=w784-h1041-no?authuser=0)

And here's the part laid on the drawing.  It matches well except for the terrible eyesore in the bottom rear corners.

(https://lh3.googleusercontent.com/pw/AL9nZEXkYzwjZAOvIi_tOWxidyesnyqspbKZ62t-D1tQOsbL69RcrC83SoY3u0fLVpSeDoCdcn9atZ4seM0_znZa0r795HXZ_ID5EKXswlaxNS2O7P5RzQwWZxCsoFEgZ4WkQHiUKMEb5vg14I2xAQhfNUOBXA=w784-h1041-no?authuser=0)

Next I turned the part on it's side and milled the features on the right side, first using a 1/2" end mill to remove most of the material and to create the relieved area that will mate with the front frame.

(https://lh3.googleusercontent.com/pw/AL9nZEW-blKg75kN_JviskQAPEANfG3DJgC5ndMYG_Djt3efdIt3itVW6eF_nEcSWFkSpJRV6TCpQSxfyNCGL_ctb-6wmAnVhClnX82YpjJx8dhPFIM8A9JRSUA5hhLkDzOMqt_Y4Ljgbq0w0ImUn0rqER4Raw=w784-h1041-no?authuser=0)

Since the drawings call for a .032" radius at the base of the raised features, I purchased a 3/16" end mill with an .032" corner radius and used it to bring the raised area to the final dimensions.  I'm not sure that this was necessary as afterwards you really can't see the radius.  So if I were to do it again, I'd not bother with this step.

(https://lh3.googleusercontent.com/pw/AL9nZEUYlDOr63yxi7R9Aj-PtOfBWcZQTFRDzjMB5WLXqVW7VNt4JvujaQl_8v9qa_UuIGeTT9P00sGyGkzeahrX_1pmasYtmzS_TomBkQnHAWbBoflw5MibcRz4NdwKoHcke_1VKKrL3XKSU_JLN15Pl5fohQ=w784-h1041-no?authuser=0)

The interior corners kept bothering me so I tried to fix it up a bit.  I smeared some JB weld in the corners and at the rear and then tried to use a small ball end mill to clean it up.  I was somewhat successful, but if you look closely it's still ugly.  What I should have done was to wait until this part was complete and then use Bondo as a filler with some sanding to smooth things out.  That would have been much faster and probably better in the end. 

(https://lh3.googleusercontent.com/pw/AL9nZEUEAWyrW2dESA-Y9w3V-engmxt2v9lWnulCkgc1TwGFrrTzqZw6lX1-kT-nLGIPP5W8W1jsVauu0_2MPDDQjiXGX8VYiBn4IZcl7P10qFceuX4-19HCHhS5M0ACuCVCv8365V6DD2gab3frd82ERG0whQ=w784-h1041-no?authuser=0)

So now onto the other side.  I placed the part in the mill vise on some large parallels as you can see along with a 123 block between the part and the movable vise jaw in order to hold it securely.  I also blued up the surface and scribed some layout lines to double check myself.  Note that I located the upper right corner and set the DRO to 0/0 at that point as the reference for work on this side.

(https://lh3.googleusercontent.com/pw/AL9nZEU9TbNcrkbk8wcYSIjj9RaR0QtdvY4Y0xe0xaMPr6j4Bf2PTOwIXI_jjKEIC02Rw9tRovB9ZxwME7LpAcBh-ZGjvZ6SCL60gkPJwhWj_u71K04A-XcC0XPkk7PRKuXfVW9EsNq6kj9whedzE5awpe-zqg=w784-h1041-no?authuser=0)

Then I milled away most of the material with a 1/2" end mill.

(https://lh3.googleusercontent.com/pw/AL9nZEVqr-n8-Xzx0ymcK-deq3P0EyoMk7lM0HsAwiY6gAWZIE4-RzSIW9RsOgMTZr1ot_RXAKf1OZPULrxkcENpYGolZ2VJm4Mv5tBxY8nQJFZUgm27NIIh_6PxWjcvzHkg1zL5cDvkZSJMzLxJ8LFLA-WXNw=w784-h1041-no?authuser=0)

Then I changed over to the corner radius end mill and brought the two raised features to dimension.

(https://lh3.googleusercontent.com/pw/AL9nZEU5Sw9EhifFOs7qYF5qY79HwvtMafgTTEt1qzzVofQlN7ijdE8GDxXVBVetPNksHQDORGyz5HFfFpC3YkHZMezacNKBHrxt4a1u40cLB1klDQywR1LL4zMU-Cqxd0cBB5vv-DoUMWSoIGvos9hW5uih9A=w784-h1041-no?authuser=0)

And finally I used a 1/2" end mill to reduce the height of what will be the cam boss to the height spec'd in the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEUSlAhAgmCir7bFr6hexS62-yYBbdLqqmm19MxR6sOHLcjhe88_zvfsdpBHTXkJNpolH8lglnTzq_Kx-DBo6BsUe0AALXF-opEyOvwMugbS-ee1ZCuWbJaS484-6XkpI_5_MfcgdKaPUfouG0KFFUUmhA=w784-h1041-no?authuser=0)

And this pix is actually a bit out of order but you can now see how the 3 major frame components will all go together, sooner or later!

(https://lh3.googleusercontent.com/pw/AL9nZEUy4QFzNSyuz_CyZOAwQsMoBxgEOdc-8s--iem9D-ETE8_XHuwUdBMIcH0kOJLLVKi5pc_pfy8dCfCVq0HTRHDZrrEDh8zF0leO_qS8bocARtj1rSEB19w6V9LPK6UVdt-OvIiqeCmphNT4u63sWW16pw=w1224-h922-no?authuser=0)

There's still some work to be done on this part and it has to be joined to the front frame, but that's all for today.

Enjoy!

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: Kim on September 26, 2022, 05:15:39 AM
More great carving there, Mike!  :popcorn: :popcorn:

Sorry about the miss on the hole depth there.  Math can backfire on you sometimes... I try so hard, but sometimes miss the calculation for some reason.  To help prevent this I try to calculate things in two ways.  If they don't match, I need to figure out what I did wrong!  But all too often I forget, or I just think it'll be close enough.  Often it works out, but sometimes, it really bites me!  But you have a good work around for it.  And by the time it's painted, no one will ever notice it!

Kim
Title: Re: Farm Boy #876 - Mike's Build
Post by: Roger B on September 26, 2022, 11:08:49 AM
Thank you for the information  :)

I use the 55° DC.., style tips and also use the Aluminium types for finishing steel. I was interested in the radius tip for the parting/grooving tool you were using for profiling. The maximum tool size I can use is 10mm so I will have to see what is available.
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 26, 2022, 04:00:11 PM
More great carving there, Mike!  :popcorn: :popcorn:

Sorry about the miss on the hole depth there.  Math can backfire on you sometimes... I try so hard, but sometimes miss the calculation for some reason.  To help prevent this I try to calculate things in two ways.  If they don't match, I need to figure out what I did wrong!  But all too often I forget, or I just think it'll be close enough.  Often it works out, but sometimes, it really bites me!  But you have a good work around for it.  And by the time it's painted, no one will ever notice it!

Kim

Kim, thanks for the kind words and sympathy!  I do try to double check my calcs, but for the life of me I don't know exactly where I went wrong on this.  Maybe I failed to zero the quill DRO???  I'm just not sure.  But as you say, Bondo and paint can cover a multitude of sins!!

Thanks!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 26, 2022, 04:19:43 PM
Thank you for the information  :)

I use the 55° DC.., style tips and also use the Aluminium types for finishing steel. I was interested in the radius tip for the parting/grooving tool you were using for profiling. The maximum tool size I can use is 10mm so I will have to see what is available.

Roger, I took a quick look thru the various catalogs I have and it looks like for the small'ish tool shank size you have, you can use only up to the 2mm size groove/turn/profile/part tools.  That may be a too small a radius for you.  Just for your reference I found this tool holder from Shars, although I note that you're located in Switzerland, so you'll likely have to find a different supplier.

https://www.shars.com/products/indexable-cutting/cut-off-and-grooving-tools/3-8-x-1-2-external-cutoff-grooving-turning-tool-holder-right-hand-2-mm-mgmn (https://www.shars.com/products/indexable-cutting/cut-off-and-grooving-tools/3-8-x-1-2-external-cutoff-grooving-turning-tool-holder-right-hand-2-mm-mgmn)

I do like the MGMN style of inserts and tool holders as they work very well and can serve multiple functions.  But with my tool holder max size being 5/8" I'm limited to 3mm maximum insert width for either grooving or profiling. Interestingly I tend to use the 2mm grooving tool the most as it parts off very well and easily creates grooves as needed.  But it can only part up to about a 1" OD so sometimes I have to revert to the "P" style HSS cutoff blade in an Aloris tool holder.

Good luck on finding what you need!

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: Don1966 on September 26, 2022, 05:06:17 PM
Wow! Nice work and craving …. :Love:


 :cheers:
Don
Title: Re: Farm Boy #876 - Mike's Build
Post by: Bearcar1 on September 26, 2022, 11:46:24 PM
Nicely done!!! Whew! a lot of steps but WoW!! what and end result.... VERY Good!..


BC1
Jim
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 27, 2022, 01:20:05 AM
Finally I'm at the stage of working on the 'smaller' bits.  They're not necessarily less complex to machine, but at least they're smaller! 

First up are the crankshaft bearing caps.  These are pretty straightforward.  I brought a couple of small pieces of 1/2" Al bar stock to size as seen here.

(https://lh3.googleusercontent.com/pw/AL9nZEW7gHyRq87Z8GOh2nhaaryR7u9hKb6DUZN1MFGA0rqO2pSD-LF4AxOD30uQMil_8tZt32L6IdC935rQa5a2GyhpSxrhe4zLSV_e5e07QEtZu264CZCkkq7im2UoFI82AI_a61GJQ0rAH_L7Hhz28GZ5Iw=w784-h1041-no?authuser=0)

Then located and drilled qty 2 #18 holes in both pieces as seen here.

(https://lh3.googleusercontent.com/pw/AL9nZEUEXrl4fdQCp1IG9WfWL0iw_c5TPSfz-VA-nOq80TlMRzrrOmN8eG2LlS6JXZGxbzfgvIpHwWd81Bd6ATWenu_Kan0QZSxt4BD2ER8EU5MCv05JjsDz3Dx9kzysYjBEZvkccR6WlxOba6ZyaUjXPJh4Kg=w784-h1041-no?authuser=0)

And here are the 2 caps on the drawing.  Note that the edges are not yet rounded over and there's not a half of a hole in either of them yet!! 

(https://lh3.googleusercontent.com/pw/AL9nZEXPbg1oDTF68kDg6tf4qRS04d6A9ShCaQrSNlRmxjEkmSJitKt-gzIyrV9kCDHQAuo_b8OibvYH1YQ_Ni66Y8cQonOfSuxD28mD33z-moahCndoxnqLTqgg1EC6mGwo0hHtU3bFkXhD7upglTfNeHrW3Q=w784-h1041-no?authuser=0)

Next is the crankshaft bushings.  I had some bearing bronze (SAE 660) round stock on hand and quickly turned the OD and then drilled and reamed through .001" over .375" as per the drawing.  I deviated from the drawing in that I made the non-governor side the same length as the governor side.  I did that because I need to fit a disk on the non-governor side that will hold a magnet and became the ignition timing.  So I need a bit more room on that side than Mr. Howell originally called for.  My method isn't as elegant as what Howell specified, but it has the huge advantage of making the ignition timing completely independent from the exhaust cam timing.

(https://lh3.googleusercontent.com/pw/AL9nZEUgXO5YPPDfcOrQMsMeJirQgIt6HTi4_55nmRM9BOfVYljZPsNgjAa3wAsnnuQd2o4kOcWJA6L46kv-5oYmOhlxB1A9Kj1gVLeV5nqGMlsweJNUN2b3E4uMCQn3RtESWkqUF1KPowQ5oxrUftzZaEgjmA=w784-h1041-no?authuser=0)

And here are the 2 bushings on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEX2Bpmlvb4J-fMM3v3JvM1gUFkQrskI5OlK-4gz9YongFm77_SidGZIUykpofwrjKtM7Qk679y1mqs6dWXeg-1cNxJhjQ8srd1u7ITuI50UKp2COW7TTjPXJjylD8d9Q1P6bE_7HK-8_YLVGcXQosio3w=w784-h1041-no?authuser=0)

And with those parts made it's time to create the threaded holes on the rear frame for the caps and for the camshaft.  Here I'm tapping the camshaft securing hole with a spiral flute 4-40 tap.  Note that I've already drilled and tapped the locations that will bolt the bearing caps.  After having purchased a number of spiral flute and spiral point taps, I regret purchasing any conventional hand taps.  Clearing the chips out either forward or backwards makes life much, much easier when tapping.

(https://lh3.googleusercontent.com/pw/AL9nZEXMNRoxMj14Rj-PUlPDPb5X7ryZwbwvaS97ElLquRTr9QcfOP32HBxZL3LWQNi-PLVuEgMC2a3cgIm01tdEHKejWIX3Ri4IQaU9xv2UyqKcMaL65H3c6x8tejPmcwsTU7bSLCs1gavK4-C9meS7YZVvpw=w784-h1041-no?authuser=0)

And here's the rear frame with the bearing caps bolted down.  You can see the ugly JB weld that at least partially covers up my earlier screw up on the rear frame interior.

(https://lh3.googleusercontent.com/pw/AL9nZEXIvFLi_f5pDZOUhFmCegoGAftMUwJkerFNPua0peQ9MvuHio1Q87n5pNFnWIeYAyFrs4GCOVkMOeV7-5cMlP5Bjq7BwuvMRhikqp1YozS2P0jWAhwFMt30Y1eZDO12MZXKoqyIcUfKz9aZPaS0Zhw42w=w784-h1041-no?authuser=0)

Now comes a critical operation.  First I carefully located my reference edges and then moved to the center location of where the crankshaft will go.  First I center drilled and then drilled thru the top hole 31/64".  In the pix I'm using a long center drill to locate the hole in the 'bottom' of the rear frame/cap assembly.  I did the OoO this way to to try to make sure that the two holes were aligned as accurately as possible.  I'd of course locked the table in x and y right before i commenced drilling.

(https://lh3.googleusercontent.com/pw/AL9nZEXO9wUYqhcGroBCK9lP_-_usLVLyRAIo2IHgKgBEZqQf6vWksy8tuFfhLyT0wzIzkrGI7V8hNzlW4Rc2uqKD-3Vn9V5UHxoWcd6gmXDyM2banYCHP_J5cuXkp-TjfAX78OUd4gGtyw4qmaU95jOadnumQ=w784-h1041-no?authuser=0)

Then I drilled thru the lower location with a 1/4" drill and here I'm using the 31/64" drill to bring the hole to almost the required dimension.

(https://lh3.googleusercontent.com/pw/AL9nZEVWdyK8VQHwXmBm_rkCni33_itFom6RVc-qwpaqX7Lledl0ltTyYPU2ztWLIGp2BcT4XL08DkOukF5IZ8bKAeSv5_SiQ7_lwAeRTZXUBwpqE35GL7pRmz3zqf7oJdpqSE7EJBcKcE3wT2_scajNxzohqw=w784-h1041-no?authuser=0)

And finally, I'm running a .500" reamer thru both sides to (hopefully) get the holes accurately aligned and to size.

(https://lh3.googleusercontent.com/pw/AL9nZEU7R4XTWySLH3d-J1Xkcnb6U8HmrXHM4jotbU2_y48Xb-VPKXyhKYm3JrV1cgaH62kog7tDMHrRLGSUKW_vhRlV5IMJZ_9S9_kys8_rN8NDfNIyIHz3bGg4IEM5H1BzDNCUmrkbK6NVS8hfOMecKaUf-Q=w784-h1041-no?authuser=0)

And now, because I'm an old, mistrusting skeptic, even though I never unlocked the table, I used a DTI to be absolutely sure that the spindle is still exactly over the hole for the crankshaft.  The reason I wanted to be sure is that this now becomes the reference for the camshaft hole location. 

I do want to caution anyone building this engine that Howell's drawing for the camshaft hole location seems to be slightly in error.  I took the pitch diameters from the gears and recalculated the camshaft hole location and it turns out to be more than a little off.  so I moved the camshaft hole location 'forward' a bit in order to get the distance between the gears properly spaced. 

(https://lh3.googleusercontent.com/pw/AL9nZEX7GKR_ClNWIPhT8PcF-4sN3v9ozyqTHthOYAOSY9IaDVwX7yPiJA6T8Dcyy73JFQt1qev6doxByamj0NcvzFo45RYIfZWgu03nmOIVjakm_fr_pJX3u4kf5DdtpNbE3mU0bk0sm2DC924gybygC4XkqQ=w784-h1041-no?authuser=0)

Then after locating the camshaft hole using the DRO and my corrected distance, I center drilled, drilled and then reamed for the camshaft.  I think I actually reamed it .251" just to have a bit of clearance when assembling.

(https://lh3.googleusercontent.com/pw/AL9nZEWXuKEDvMl1lDGta28y89zrpotc9mjEJnET09TAglu0RUfW04K419lhZVJbSKh1LAPkC_fhJDsCIrvcQ_4PD5vVcLFrm0ykjLrnxwtU49UDiunzDxfRwD3ZDrl4m9gxDsWgwrfZHW0JIJeJlFay3BuM7g=w784-h1041-no?authuser=0)

Then to check if I managed to get things right, I installed the bushings and the caps and than ran a piece of 3/8" drill rod through both sides.  By some miracle it passed thru both bushings and actually turned rather nicely!!!!   I felt pretty good about this as this is definitely something that will prevent a successful build if you have the crankshaft in a constant bind.  Plus you'll note I put a pin in the camshaft location just to check the fit. 

(https://lh3.googleusercontent.com/pw/AL9nZEXfWjOsGbmuFmBCsjK0MK8G_LRjasiLQckOSwIxJHDd3ii4K_2TZbocS-gBYl25t7FN3VzlnrG6TsnS0RIa60MnEGTunNmF1NRbZZmXL96bJSz7dLJCHdFNxRQUYaVzVSLL7FPkWqQT9hkAdeTPrHu6gQ=w784-h1041-no?authuser=0)

So the only op remaining is to do a bit of rounding on some of the edges as per the drawing.

Here I'm rounding the upper rear corner of the frame using a corner rounding end mill.  This is actually a bit tricky as the assumption when using these end mills is that you're working on a 90 degree corner.  The trick here is to NOT cut as deeply as you otherwise might.

(https://lh3.googleusercontent.com/pw/AL9nZEUw_R9nYB7Y7ulc6TXx9odg3R4XstMfeKEMVY5ll9UNW7ymXvKTeVLTZQP2b3RgT8eFeZuDiZ_Us9-_EBfBklBiy4jezqz6usJIrPROuKc7XfmjrIjmtjSB0kiolnNcH7Qxt9yakxl1CI7fOR882xEb6A=w784-h1041-no?authuser=0)

Here I'm starting to round over the corners of the bearing caps and the mounting area just below them.

(https://lh3.googleusercontent.com/pw/AL9nZEUs-IDKj8QD1NTvf6ozmV-Xc3_GFvHJ5mfCqEVc2ekEvyjHUeMNfkvNXuxL_7xkpo0pc1QX12tJIiFjhdQHgT6l5-GRAemRA0aL_fGl94WUntTga4yqs1QZbFPfJkp6kcEW-98jouEVKrNAZHlcsYOq8g=w784-h1041-no?authuser=0)

And here's the rear frame completed with the corners rounded and the bearing caps installed.

(https://lh3.googleusercontent.com/pw/AL9nZEUmL253Sg0Uy4BNp9SMBq7FyF-YQwiIU8vZXl_SU6ISCaBHTENSh3MQxYzNRVNkzyZITsSVlit34msHgt5-8qYtNWCfF6kIbjKII1VSyIML0IOxRyQGla8-b-SUv2XplTdxYSHK-ZLhyXif3BfNVZCmkw=w784-h1041-no?authuser=0)

And that's it for this series of operations.  Next up will be assembling the front and rear frames permanently, but that's a post for another day.

Enjoy!

Mike

PS.  If anyone wants to know the distance between the camshaft and crankshaft locs and what my correction was I'll be happy to post it here.  Just let me know. 
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 27, 2022, 04:43:01 PM
Now that all three frame parts are completed, there's one more big step, that being to join the front and rear frames together permanently.  I followed JE Howell's exact process as it seemed entirely reasonable to me.

First I needed qty 4 flat head 2-56 shcs.  I had some longer ones in stock from a previous project so I cut them off with a cutoff blade in my flex shaft tool and then cleaned up the ends on the belt sander so that the threads would start properly.  Here's a before and after with a British coin for comparison.

(https://lh3.googleusercontent.com/pw/AL9nZEXHr0DMWH5uJatgBtFd2yOmbAcqqHiBh484nCNvm-d0uC-W9FJV2TC6Qvn5avUZozSu86qWTFFmR4pXtLLTUngmyomLOPOnLxuWSzB9cUVCmvNFPXxFoHNAfaGIC4L2qwbkqn8QmISYTxt-pf_jAEKO7g=w784-h1041-no?authuser=0)

Then I mounted the 2 frame pieces in the mill vise using some parallels and packing and a large C clamp to hold everything together and aligned properly.  Then I drilled and tapped 4 locations as per JEH's drawing.  I carefully tapped using a spring loaded follower and tiny tap wrench.

(https://lh3.googleusercontent.com/pw/AL9nZEXqDmKuWXkrSJZCqxVnw9mWxrvBgtryoijRt-vOZCIyA8xc7nj9g0_rrJZ-B3O_dCElOh1CLrcIE-wAJnWelED8gqZNnC-fsIfvPlltOzbOtQYZ1Dnfm8ljQWsKCy4CSE03gaahb45cD1i8OpnEPrHG3g=w784-h1041-no?authuser=0)

Next was countersinking the 4 drilled/tapped locations with an 82 degree countersink tool.  I went deep enough to make sure each of the heads was below the surface of the part.  The only way I've found to really get the depth of a countersink correct is to sneak up on it using the quill stop to slowly advance the depth and then try the fit of the shcs after each pass. 

(https://lh3.googleusercontent.com/pw/AL9nZEWVTUn0SNcKlu8aHoyAjpIukdhX-27_vJbLaV0fv3omjKgnqLLqwC_F5QHd_lkMvkMCFzApXuyPdqkV2jd5MF2jWRCJ0SYXyV_4qn1YM-wiMaKWpoZpKIEBA0G-YubZzTjozJwtu7eZ7qwz3AcNxkzEZg=w784-h1041-no?authuser=0)

And here's what the engine looks like with all 3 major pieces assembled.  This is a major milestone and it is really starting to look like an actual engine!

(https://lh3.googleusercontent.com/pw/AL9nZEUmaSacnnnTxun5ikx8uV25u9F00o-RClPg02t_tRA97kWI7DekmRnT-dEzePvYlOz_vqFC1S6IBWlqoNVs3AbEFa_dOko0EMbCeOhqd5UJzucOEeL1RYQ5_PhlBVMd5p9OUestfQfNMVp4nvqb_IqMDw=w784-h1041-no?authuser=0)

Next is actually joining the pieces permanently.  Here I've mixed up a small batch of JB Weld and applied it liberally to both surfaces.  To get the screws into place, I used the large clamp to draw the 2 halves together and then installed the shcs when the holes matched up.  Then I wiped off the excess epoxy that squeezed out of the joint. 

(https://lh3.googleusercontent.com/pw/AL9nZEVFzo7BOqlgI89eFcN7MoQnmpPaD-UuQWCKfg8XC4u75ZpFh0MfIvKT2XqKZBmlxQsDTW77DOrQU4wSzha_nUH-CRr3ZfbhlVVPe6fKEuqPD6OgH92rPIf-RhTuNw0vwgUbn-XFnPF5e8SK-qO4hlB3Lw=w784-h1041-no?authuser=0)

The next day, after the epoxy cured, I drilled at 2 locs from the top as per JEH's drawing. 

(https://lh3.googleusercontent.com/pw/AL9nZEXaAzoUQ9IOMlnjX-e3x1uyF2i4cPzNwMbfnPglq5QzWJmju-MIthWYT4N4OVJZTnN2DyxT-D_LBuRF4nuatiwjsPk3i9QaMziX6-trne8H7xbY2vWVBIkGbrhbj7TeC2U_a7VdsEOGugzVmiS7kG64fw=w784-h1041-no?authuser=0)

Next I liberally coated 2 small brass pins with epoxy and shoved as much as possible into the two holes and tapped in the brass pins until they bottomed out.  I wiped off the excess epoxy and here's the final result. 

(https://lh3.googleusercontent.com/pw/AL9nZEWDGnPC9Ydc3CwUeT3gx_VbwKtwPyZ0m-vW9saVWVpoM0H7ZEWbQC1BpXes6QmJ3hotF-EL7xS_PnnpsrGVoYdFjwb8pli9tOfq8DttDJnT6dYNZLuw6Pl_AZtzBrRrvvBuXRazNzSzNgL8O2nw5Od_gw=w1224-h922-no?authuser=0)

I'm pretty confident that between the 2-56 flat head screws, the epoxy and the brass pins, those 2 frames halves will never separate!  It felt good to get to this point!

Enjoy!


Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Kim on September 27, 2022, 05:04:26 PM
That does look very secure!  How deep did you make the pin holes?  Seems like the pin hole might cut through the screws you were using to hold it together if the pin hole went very deep.

But I'm sure it's a very solid connection regardless.

Kim
Title: Re: Farm Boy #876 - Mike's Build
Post by: Admiral_dk on September 27, 2022, 06:14:34 PM
A very fine result so far - so I can see why you are happy with the parts shown  :ThumbsUp:

If you haven't admitted up front that this isn't a Live Build - I would seriously wondered if we are witnessing someone faster than Chris and his Elves  ;D     :cheers:

Per
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 28, 2022, 09:23:09 PM
That does look very secure!  How deep did you make the pin holes?  Seems like the pin hole might cut through the screws you were using to hold it together if the pin hole went very deep.

But I'm sure it's a very solid connection regardless.

Kim

Kim, I just checked on my CAD model.  From the center of the top hole to the top of the frame, it's .625" I drilled from the top .50" deep with a #41 drill and then used a .093" bit of brass rod that was .40" long.  Doing it that way prevented drilling into the shcs and leaving the brass rod a bit short left the top a bit shallow at the top so it would be easier to fill with Bondo flush later. 

I can't imagine those frame halves coming apart ever!  And there have been a number of Farm Boy engines built with no problems reported for this joint.

Glad you're following along!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 28, 2022, 09:26:13 PM
A very fine result so far - so I can see why you are happy with the parts shown  :ThumbsUp:

If you haven't admitted up front that this isn't a Live Build - I would seriously wondered if we are witnessing someone faster than Chris and his Elves  ;D     :cheers:

Per

Per, I was indeed careful to disclaim that this wasn't a live build!   I'm certainly no speed demon.  However, I have already selected my next engine to build and I will make every attempt to document that one close to real time. 

Thanks very much for following along!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Bearcar1 on September 29, 2022, 01:33:04 AM
Nicely done!! Mike... I am still following along and enjoying the ride... Boy oh boy, that is alot of work,,,, Very well executed.... :ThumbsUp: :ThumbsUp:


BC1
Jim
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 29, 2022, 09:30:19 PM
So with the major frame parts permanently assembled, it's now time to move on to the rest of the bits.   I decided that next would be the cylinder head.  It looks like a relatively simple part, but there are a fairly large number of operations to get this part completed.

First i turned the small feature that fits into the cylinder liner.  I had a short piece of 2" Al so it was just a matter of polishing up the OD a bit and using an insert tool to turn the feature.  It's .100" high and .998" OD.  I verified the fit in the cylinder liner.

(https://lh3.googleusercontent.com/pw/AL9nZEVuuq2GczFcKnB9GKsFe5TvnlbL-dxnVpz4JWFHPVNgvKIoZ9srUk8PPySh2W7nv8p3HhSWRkZA5dizG14Qw0Q_KuW36KfDqGob5j4TVvkvtpHFGhZ2b_GqBSeaU4mKlQFy7imevcixheeEsfSX3HBf2w=w784-h1041-no?authuser=0)

And here's the head parted off with the back side cleaned up.  You can see it on the drawing for comparison.

(https://lh3.googleusercontent.com/pw/AL9nZEXcZ3-3FK1ToTMEni4SIXXGXrdHb-C3_EhEYkj_NLQD8X6pK2WDDB3NkSKcmSlewT6mdz2QfhpDeRq8V8gjtPnbR9Z-NyrPZ3TF_q4aM6KpcjaYG5SfZAjFjPJAVOQ6Nbj_WL5aU7TupX69PfuqXYkIMA=w784-h1041-no?authuser=0)

Here's the part in the mill vise after most of the features on the bottom side were drilled.  I'm reaming 13/32" here for the 2 holes that will accept the valve cages.  I'm holding with a v-block against the fixed jaw and a small scrap of Al between the part and the movable jaw.  There are parallels under the part to keep it oriented flat.  Of course I centered the part under the spindle before doing any of the ops and placed the various features using the DRO. 

(https://lh3.googleusercontent.com/pw/AL9nZEWnqsTLb0ZIXcAfzbYxrPLBD803-nf4G_vmP-TQrzwEzPVxQMo6mk7KLg8id_a9VgqSm6EVWOAWIQn7zj4mUV3lbSR7lDN_Oe3gFA0_914mlwQuWBU-vAWRWLdpqvLHYILLnLJf5l5W9kxCF-fBXKGgxQ=w784-h1041-no?authuser=0)

And here's the part with the bottom features completed.  The round recess was made with a 3/8" ball end mill plunging .285" deep.
 
You can see the drawing I made from the CAD modeling I did.  This isn't strictly necessary but I find that it's more convenient for me to put the added dimensions I like for the way I tend to work. 

(https://lh3.googleusercontent.com/pw/AL9nZEUXWD9vwWEwwoIkCsr3XOtHyBD5ABR5GzFbGG819AY3NIuMHXJjBtFsCuXMxMaeu3RjGWXxuHggG2kuMTT34-EFiWWxQ5FipqG3FTvVzvP-PLZm4N7EYjFNdVVeSCXG5wWXXDLdMU3y330zOClqH5RQ7w=w784-h1041-no?authuser=0)

At this point, I needed to create a fixture in order to complete the rest of the features.  I had some Al plate so I cut out a piece and squared it up to 3" x 3".  The size is pretty irrelevant but it needs to be square for reasons that will become clear later.  Here I drilled a center hole in the exact center of the piece and then drilled and tapped 4 6-32 hole that match the mounting holes for the head. 

(https://lh3.googleusercontent.com/pw/AL9nZEU046ASuPQI73rF-9Mrz9CSFbIXwoqHjGF0aMvWv-ASmsLrEhcamjrgVZMgdz3nW8z9VjhrFnpu9igP16f7IrfJlQYS7n22wmGEphWNu8o5krxUDJ2C3VFB-mdCaymJgz95AkE5WCPOP3QSHEoJHNUldw=w784-h1041-no?authuser=0)

Then I took that piece over to the lathe and centered in the 4J using the center hole drilled in the mill as the reference.  Here I'm drilling thru 7/16".  This will eventually become a port for an air fitting that I'll use for pressure testing the head.

(https://lh3.googleusercontent.com/pw/AL9nZEVaENvBZW4wo3QUq5N8f8v48AtARJVKTQKlZgc8H5Rp-dcCKvXVJqLJIutfk62EdIusvbcy3CtmXtnB34yX_X5JwblPUVjuvy6GuiBYHJvLsyxGv_o_e9VLa1a5L60QJqBSz9HkISKBAjcPD4_2baFW-A=w784-h1041-no?authuser=0)

Next was boring a 1" ID recess to accept the raised boss from the head. 

(https://lh3.googleusercontent.com/pw/AL9nZEVOfEsEFQ_xaC6qAhtGxA2kBl2dSTu6kpTtdVuPtox-zTNIY9vIBhyuw0ly4VICOIUAOFAoLQIyMibCG4iVZTs7552ZIErZAAvjRwScS3OCjRi-PHeQlQ2e5DDII2rvEmrqVc0FnbqGu5yxvNoWuZwu2g=w784-h1041-no?authuser=0)

And here's the fixture and the head next to each other.

(https://lh3.googleusercontent.com/pw/AL9nZEXzG1xyLuYT9gl7RoB6tjazdubguM7D1IfTH5RaY1c-mVhcxRj59nvz3W6wZnVhvCqdXdZEhmQxtp__ku5xJy7HKr_FnRwSPS3amf2oKmxUjFCFQvFLR46bCZI-gETcxwheUB9IdO-pM-kqWcG-dtUcZw=w784-h1041-no?authuser=0)

With the head bolted to the fixture, it's now possible to orient features front to back and around the  OD as required.  First I located, drilled and reamed for the rocker arm pivot mount location.  That's a 3/16" reamer that does NOT go all the way thru the head. 

(https://lh3.googleusercontent.com/pw/AL9nZEVsIgwjB4nnc1MmeStAeTdneaLK8p19AEcO_YkpJsPww4WHthYiBsy3wJhPY4n5ay62z9iFFcIu91KV6SGPZG115s0sJI78GNT9Nv6njPzQEgY4maH-kCTuefFNbKt74_K_oR2isH8nxvcVeDafoXXhhA=w784-h1041-no?authuser=0)

I then made a small center hole at the location that will be the center of the angled hole for the spark plug.  This is just a reference and I'm pointing it out here.  This was done via the DRO.

(https://lh3.googleusercontent.com/pw/AL9nZEX6VZj7MyUb6rWeBYVTAbapchGKgIh23jrNKxz5ZL5jum9QzC_2ab1rl6jsrFxgX1Iw2705zA-DpRJnydnLtPiS-1x-GQ_JguoTzbwmB3MYTuVaxAy1OSo-ROuos2c_zt7SajvFZ-74_pCJjGJrdsPJVg=w784-h1041-no?authuser=0)

Here's where the fixture really comes into play.  I've reoriented the fixture in the vise and angled it at 20 degrees using an angle block under the fixture.  Since the fixture is square the distance from the fixed jaw is always known for y and I just have to locate in x.  I'm just visually aligning the small center hole with the sharp tip of an edge finder. 

(https://lh3.googleusercontent.com/pw/AL9nZEU_M_AgU7HySsILrHwxKcrSm5Ks6Bill5B9XH5iWRSzkiF2gAakFUTJ1LGuDOHb0IyV-2iZpRCoWiK7vj0c4aoJQ-8UQPvtstHN5QM7dg73TWx_A4IQeGzh8qR74mc5dlLgSixmeOHk_4MmyV5Pra-Emw=w784-h1041-no?authuser=0)

Here I'm plunging in with a 1/2" 2 flute end mill .350" deep.  JE Howell's drawing calls for a 7/16" counter-bore at this location but I enlarged it as I want to be able to use a thin wall 5/16" socket to install the spark plug and the 1/2" ID gives that clearance.

(https://lh3.googleusercontent.com/pw/AL9nZEVTdHXsbivmrzqx7LxVmSC1lI4JVQ20tgmoC7I7MxwITqd8PbVp5ZH4j5uMfqvj-IB_8TyvLRpAsprXPG0d0aXEncjPjKuC-NTkaP352Dv7vcCIBkg_wS_BpZlJLrRj7kBObNqufZW_6SUxnOAjmrgcgA=w784-h1041-no?authuser=0)

Then I drilled thru and tapped 1/4"-32 for the spark plug.  I did touch this with a center drill before drilling thru, but this operation was easy since the drill intersects the surface square after the milling op.

(https://lh3.googleusercontent.com/pw/AL9nZEWnGJ8l5aRo2835BNj6uVZn6WwiJK0z01Mz_Xetea4f9W0csDft-irL0cxI-voXbBN-pJ5rSR_tXuL9k1343_GGzQg3JOWSN9NzPaUPai2BeVxcbFhlZceEMZ8_BGWEv0KTw89KlL9aINkP0UQ9jPW5Rg=w784-h1041-no?authuser=0)

Next I reoriented the fixture in the mill vise again and found the center of the head in x.  Y is known as that reference remains the rear fixed vise jaw.  I'm using a 1/2" diameter edge finder as that can easily find the edges on large OD objects.

(https://lh3.googleusercontent.com/pw/AL9nZEXVLBwDdPPVZGkfbVQkOBe-sh5GouKEx-qhzxaawMq8ArcCrnFY_pTOx2EiLlvBYXw4_WchTgT1xFrl2pjsXu_08ZQfFRSQUPynkLc8KJBXtF5ibdHSdPh0_8ngsRxjroDovV7132y4SfXSEgzRYiBG3w=w784-h1041-no?authuser=0)

Here I'm gauging the depth of the hole so that it just intersects the 3/16" hole.  I did end up tapping this 4-40 rather than the 5-40 that the drawing calls for.  I did this as I typically have 4-40 set screws but don't typically have 5-40 set screws on hand. 

(https://lh3.googleusercontent.com/pw/AL9nZEVZ9i5uQSbebbi5KlSDeSZo_cz_heEYbEj6hqP6xfggX-XK85xb9qOkXQeIght_lpoCYQTnfHncPIQ7XhJI5eFDhN0rWDZD_H7vUt7Ywce0Z97kK7f7BXJB72yXWqLGwjPy6ShtaFN2T_o2RR7Tw1qVJQ=w784-h1041-no?authuser=0)

And here's the cylinder head assembled with the spark plug.  There are more operations to be done on the head, but they can't be done until the valve guides are completed.

(https://lh3.googleusercontent.com/pw/AL9nZEWVBoXTXMezvBifwxqGxR2hx9nxc7FQoAWjjD8Fb1k-l7NImjL-ykt5YXvV2XwIRFyRysbYx1uRwLKquoxfZJwrN8VnGNV7XnV7EW_aeipDjFsp0Ov_HWlQHGDF-MBQ0wPiew9UKrF5HJdrfMhMLpbLiA=w784-h1041-no?authuser=0)

And that's it for now!  More to come as there's lots of little parts that are attached to the cylinder head.

Enjoy!

Mike


Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on September 30, 2022, 11:52:10 PM
And here's the last bit of work necessary to finish the cylinder head, at least with the permanently installed bits. This is of course, the valve guides or valve cages as HE Howell refers to them.

I decided to use plain 360 brass for the guides vs the phosphor bronze as the drawing specifies.  I based this choice on the 2 previous I/C engines that I've built and successfully ran and also on the wise words of Brian Rupnow who almost always uses brass  guides for his engines.  Here I've put some 1/2" brass stock in a collet and turned the major diameters and the pix shows reaming .125" thru after drilling thru.

(https://lh3.googleusercontent.com/pw/AL9nZEXvsPHFBu7-_qfzBEJPuBUgW-_-HaKXmrD4kHHZriUuHTPlgCz9hsJgUaecdKxXjoBoO_2DjhH0gijYGrzmhfIyCv0bQb-W8mViMuwb7pWJO1QoGJwjwFP0A5a8H2BDnAmDcinKa8cU1Xq0DkaXwgQxCg=w784-h1041-no?authuser=0)

Then after parting off to length I plunged in with a 5/16" ball end mill to create the recess with bottom rounded as per the drawing.  I just held the end mill in the tail stock chuck.  It seemed to work OK, although there was a bit of chatter as I was finishing up the plunge.

(https://lh3.googleusercontent.com/pw/AL9nZEWvjoFfhm0UWB3EuE4uTTw-XmWhKQOt7X0wa-j9Lgu4ej_90Mn5mwZvluJ_i6szetoGhQbgi28bHLMHRgHJTxvKg3yYU2-SdfwVVSmPZqGChrrthPnS6l0luEiRhuuK8-xXJXCJanIu3Q-K92swxXwYHg=w784-h1041-no?authuser=0)

Then I turned the part around and turned the taper using the compound.  I think this was a 4 degree angle.

(https://lh3.googleusercontent.com/pw/AL9nZEWN0ucaw-hy-n3aqaqXJMGDbFOvNYG5jIFcapk2v9ii2MMLYUKe5Yt4oxiCojCBfZSmEZSeq0vMGpqsVxAgxKKyG7RZoeFwM-7VxBaBn5Hdq-lcaWIgMFcDK6-4Pon7KD0TLg7k9k7apLex3HmRoVl7Aw=w784-h1041-no?authuser=0)

And here are the finished valve guides on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEXp2NJzL-YVT5s-NkCGDeDNBXCX4fMEK49nLHjTtt5EywbUHYP9gUH6Aoxup6cqSjO-6nMrBTAbaJh1HdZz7vP9n6gfD2jOFA8LeMiayAxQ6B41-6Hh5O1CO9mTSevafHjHXtafcY_o9_5HX0OmGA14vA=w784-h1041-no?authuser=0)

Since these guides need to be pressed into the head, I made a simple tool for the pressing operation.  This way the pressing operation can be done without damage to the guides.   This little tool is just made from Al round bar.

(https://lh3.googleusercontent.com/pw/AL9nZEWt0jWLrPg6SHTQjUj1SJFheTTO5C6b7kPmW6I-3_bnrtNOegYZggfcVlB_8VdJV5mdrZlekVXxj50qWPvK2gsUfvWHBSrkee0e3jDKYGXQWshT6u64W5rc6MvkCmzGx8VsIGHNIk2gIcaJXjFlP5MeEQ=w784-h1041-no?authuser=0)

And here's the pressing operation.  I used my old Dake press and I coated the guides with Loctite 620 prior to pressing them into place.  The guides were what I would call a 'light press fit' and my thinking was that this fit plus the Loctite should form a good seal.

(https://lh3.googleusercontent.com/pw/AL9nZEWfSpxbNaXKe794xgRHPo1jwyDz_dXhCu3LscqLMOxtV5TxA4tRF4dzX1blBSAqXMN1oI2ghUFbrbh96MHWasBIhPIY7wrIl-L7z8oKZLcs7M_n5xFZO58mMrS5TsUn2GOj6pRA-ZJ1JNXq8acReSOZQg=w784-h1041-no?authuser=0)

And here's the head with the valve guides installed as viewed from the top side.

(https://lh3.googleusercontent.com/pw/AL9nZEVeXHwj7BgBhem7T_K7i8VqtDsWwAeF0pAUFUR-WLERvVjT0YvDJt7acX6pVYVIGQfI5Eylf_vkb8-bDvINE9eZ3y6GqBnqHF5JY4q6d02tE0CHom2w2XnmdoPsSfdXI1g5xYKQT-RdnLlq84Q-rUN2Ag=w1224-h922-no?authuser=0)

And from the bottom side.  You can see the chatter marks at the bottom of the guides.  I made the judgement call that a bit of chatter at that location would not matter at all. 

(https://lh3.googleusercontent.com/pw/AL9nZEU2-GC2dXniZXmxsw022WcXuo53e8d9uNPq3FJwkQx0ZV1_VEa6gRLs5c3Ktutcun3x3SjiPhCDrNqNmMvzBPt3MxKVXsADpd07xxQY0_R-l_qtCJMRA858OASKoNuQHJc671nLrH4g8rG4Zg_TWRGCxQ=w1224-h922-no?authuser=0)

After letting the assembly cure overnight, I then placed the head back onto the fixture I'd previously made and then drilled thru with a letter "I" drill and here I'm tapping 5/16"-24. 

(https://lh3.googleusercontent.com/pw/AL9nZEV5QXcYHjsr-w0IQeVs_ZG7N_nSJMvIoL6DqUfJi7om-L2Qt3nQLyVBlcksiawEgi3F3JOWzWMCo5oheQ6JotQTIlk2gkv_EPEO6Tc4oL2vxVYEfqd1jdBE-4s5u1vOkp8t3xD0YYfPYQd8BoDHiI9vhw=w784-h1041-no?authuser=0)

Then I reoriented the fixture and drilled and reamed for the intake passage.  This involved milling a small flat to get a starting point, center drilling, then drilling thru 1/4" into the valve guide and then enlarging the hole to .375" to .440" deep.  The pix shows reaming .375" to create a good fit for the pipe from the carburetor. 

(https://lh3.googleusercontent.com/pw/AL9nZEXfyJcIYqZP4bG3Y2z6Ctg_8rtyo08Rm13uhzINhAUKTZ6U4_M0ohTBDBMoy5mPhivDyfdZ5XnrOk4maOnyDJ435JpwgJfG0gD6E8EaBKsXLA-vucRTzAuN7TUXUQarjV7wxi3JA18ZgXe63kOor5ljqQ=w784-h1041-no?authuser=0)

And here's the now completed cylinder head from 3 views. 

First looking at the intake port.  Note that I put a small chamfer on the head just to make assembly a bit easier plus I hate sharp edges!

(https://lh3.googleusercontent.com/pw/AL9nZEW36fPJzNHrk9eJuKEKE6RZ5B6d-J-a6holu4JxpLIbkt0bR8SC54PO0b1wmZYG7cmLk3Ci7OjZm4SXBKVTzR8xN8C6OqA0bCTVxDPxCnyteSFKExlYNmK8GNBsCjQfalgc0TBZnBzf7yddKmlDuKepUQ=w784-h1041-no?authuser=0)

Viewing from the exhaust port side.

(https://lh3.googleusercontent.com/pw/AL9nZEXlinyi0rbIOImYZY02iHYcV5clEQ4YMhdYc3d_pcfIEO16pQnYIEh5-CSzWYqGlHiH9onto_olmE0JvANylbPYwCOFI80arx4nGrl4IpA_PoF7vJlmvKKnOURRfnp8KpY7jXE3OeAGi7GXDa4ydZwszg=w784-h1041-no?authuser=0)

And lastly from the bottom.

(https://lh3.googleusercontent.com/pw/AL9nZEX9hm_8RlQHXZfeNeC6nXhCT1qXSGjhONVmmFmUlEuWd4AKlepA9N6XwIFEWhvxlUSVXAWQcIFxST5GkZAkfXNvn-FObvs4cYB5-JvnmBsJDEG-nyo90GFdKQz6RHWhbUGqtXM4j3w_eLJZRywnq-1IQA=w784-h1041-no?authuser=0)

And that's it for the cylinder head!  Although there are a lot of steps, it wasn't actually terribly difficult once I figured out the simple fixture.  That really made positioning easy!

Enjoy!

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: Admiral_dk on October 01, 2022, 11:05:27 AM
That is a fine looking Head Mike  :ThumbsUp:

I'm sure you are right abouth the chatter marks @ the very slow speed this Engine is supposed to run.
Plus they might actually help the Air/Fuel to mix even better on the Carburator side ....

Per
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 06, 2022, 01:19:39 AM
Next up is the crankshaft.  Howell's plans call for the crank to be carved from solid stock, but I chose to do a built up crankshaft as I've done it that way a couple of times previously and both of those came out good.  So here we go!

Here are the raw materials.  Some 3/8" drill rod, I think W1 and some bits of 3/8" steel whose identity is a bit of a mystery but it acts and looks like and acts like O1 or A2.

First, i cut one piece of the drill rod to the overall length that I needed.  I actually made it a bit longer than Howell specified on the right side.  I need to sneak in a delrin disk for the ignition trigger magnet on that side of the engine and need a little more clearance.  Additionally I made a few other minor dimension changes as I wanted to leave the throws .375 vs .382" on Howell's drawings.  I did model the crank, engine frame, and bushings to make sure everything fit with proper clearance.  Here I'm drilling center holes on each end of the main shaft of the crank.  This is partially for appearance and for turning between centers should that prove necessary. 

(https://lh3.googleusercontent.com/pw/AL9nZEUU-tzjENqNLWSDRqHVW9DMWi_XXPRdvOq0ykgpS2OnoEZgpZHL6AviH9IYeGoxepyHzq6VG72Y17s8sS9g-CgtiaLYishgLfxazxKuzDEY-ih4U0oFCdhQ4ETRxS6_CFBXytpiBLXwoQJzBF-49tcoXA=w784-h1041-no?authuser=0)

Here are the 2 pieces of drill rod cut to length along with the 2 pieces of flat stock Loctited together and clamped together to cure.

(https://lh3.googleusercontent.com/pw/AL9nZEUpCBOzZLfGo0rHftBz7WYcvhtCopZYi-6rtmMas2tnJltTs3gwytIUS6kFcYhYZOATo4UpWWeqqYfTnP9h5RXjdxNLX25DeiXRQJSNLceu_Uob8YoIrpzFVbNiDlM2MgkqH1OmlJWhY2ojkx4b8inX7Q=w784-h1041-no?authuser=0)

Here the holes for the throw and the main shaft were drilled and reamed exactly .6875" c/c.  Note that i did this operation with the 2 pieces Loctited together and held in the mill vise using some Al between the stock and the floating jaw.

(https://lh3.googleusercontent.com/pw/AL9nZEXIRs-0MpucRndwjtsd708pA2Eniz7hSCei0niK123EnMCtSHLODY2zRXAqOQyA4_wpTgvs1Vu5VT7ouOxZTPlPgXi4ii-5dfelfsQtlqE5Wms6PCkbpkpUH1rk65UvpGkKv2Eske0-fsFIquztiCE4jA=w784-h1041-no?authuser=0)

Then I rounded over each end using the rotary table with a pin to establish the center or rotation.  I did this op this was as this is way easier with a built up style crank.

(https://lh3.googleusercontent.com/pw/AL9nZEU2z6CjXr7zY9jh5se6UxEGGB_wQ5lsy7j7DE2cN-nJX1zsd8M1fkjlUyEAMdTBmgmgXf1DoWXGVGKbmM1qcOSnmRN6f7cmPq9Ht5ioeeC95zIHkBub5xm4-ciIWLx3tGrhZ151-l9-KRDlosJZizELng=w784-h1041-no?authuser=0)

The throws finished and laid on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEXqaU41TY5Mk5Am-WZSeFOGaAQBt8YdJskXlL5nb0D8JsxsHivaATJoB7pmjJ9FGItvPVJLcpHyozP4m0yXTiWUDQqmEHgUa3kU8ZURri7QabWmbQCLzqtO82_PtBFaldUNUP4XDenRKXyrbfOV1VWFUQ=w1224-h922-no?authuser=0)

Then I milled a 1/8" slot on each end of the crank's main shaft.  I'm going this different than Howell as my intention is to use a key and set screw arrangement vs the hub clamp. One thing that I figured out is that when milling keyways, the specified depth is taken from the point that the cutter creates a full-width flat, NOT when the cutter touches the top of the rounded surface.  There are calculations that give the depth required from the touch point, but it's just easier to mill away a bit until you have a perfect flat.  That's easily determined by scraping your fingernail across the area.  I used a 2 flute HSS end mill turning about as fast as the Bridgeport can go plus I used my MQL system to keep the slot clean and lubricated. 

(https://lh3.googleusercontent.com/pw/AL9nZEVvHVsrePtRq81X4pAlei-L8I6qmIongY63MTB39pN8qwzPlHXV32GU75yvliIsBIv1flr9EG_5wigf-U4_7Ycd2kS2-fLTIlZO0etXJEPqN2KZVfIz5q5Rms5dGoi65cxOQzlBOZuZuYGDmmRN7PiCJg=w784-h1041-no?authuser=0)

And here I'm checking the fit within the frame and bushing prior to permanently securing all the pieces.

(https://lh3.googleusercontent.com/pw/AL9nZEUtbPt6DSVqE6i_oYHKfiplrugYO5XPWOxigh_qIgoT_CZ89YCYalkPaQlXs9Pumtemj5tGPKgLCz05rEv6X6aVMpC2OpGo2SUXyGrh327JlmRcFCWdnsKuYgScBE5mwFTfjUi-l_D0J6LE7qthApV09A=w784-h1041-no?authuser=0)

Next i applied Loctite 638 to all the joints and carefully positioned the pieces and to make sure the spacing between the throws was correct I clamped a small bit of Al milled to width, between the throws.  And I assembled it on a surface plate to keep everything as well aligned as possible.  I then let us cure overnight prior to the next work on it.

(https://lh3.googleusercontent.com/pw/AL9nZEXZEluWY44I_lXx4DT7yPG5FHy0vqaAOhJvBY_sI9_ZpjjyfoW1KQinTFDWRGCgCthnuaTrejYzivcPURoeBQjYgbg5U-gAtehi5ul4q0QHnRDZQE6ZrNI7fF1XD0gZrWoGoeGdWxa7kib3Z6_VCaY_IQ=w784-h1041-no?authuser=0)

To further secure the joints, I drilled thru in 4 places and drove in some small finish nails liberally coated with Loctite 638.  I carefully selected the nails so they were each a very light interference fit that took just a bit of tapping to get into place.

(https://lh3.googleusercontent.com/pw/AL9nZEVnk9TyKMisY3ii20OPZfvt45Cc5BZDqN1qK7frAgGV3PEtt8aWYbYfjX6b7IGCDtNjNzsPz9xrHOE4Z59zDIul7aiJQblAi1N5HPgk63MUKGALp98i75QQ-NZmOmWwZy_toAeuxl5SKXV5nBX-qDxBUg=w784-h1041-no?authuser=0)

After that i clipped off the excess length of the nails and fully flattened them using my belt sander.  Here I'm milling out the section of the main shaft that has to be removed to turn it into an actual crankshaft.  Believe me, I checked about 10 times that i was milling away the correct bit before commencing!

(https://lh3.googleusercontent.com/pw/AL9nZEXZj5TwW99BM3qLds8K8elBS-3TGLaHsVMr4S8c3S5mDKhhljzT2MXMP3c1wfhyiyD_rJrZWIVF8Wad7rO0hGdvK1HzkqFFtdd0ByAXYLnMG0C5CUwD-nNgBhPMs2P480cVNoNwfTJzxyXhqxXirFtcRA=w784-h1041-no?authuser=0)

And here's the completed crankshaft!! 

(https://lh3.googleusercontent.com/pw/AL9nZEU3QtK6g28Zki8xbMzDF3VXwFzfI5rZtkuZKomlH0fBSW9_1M9JAF2HOYvEt_633T66-jFdrke02bOHLWelEZgvMEK9JSRJloKcdF0IuEl_fbQkKzdZFR5gBk83dGUHbMex1-9khBg5cTEfaIizI8ZVQw=w1224-h922-no?authuser=0)

And that's it!  I find this method of making a crankshaft entirely satisfactory.  I think the Loctite plus pinning the joints is adequately strong for anything that this engine might experience.

Enjoy!

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: Kim on October 06, 2022, 04:57:54 AM
Great crankshaft!  Nice set of pictures showing the steps you took to make it too!  :popcorn: :popcorn:

Kim
Title: Re: Farm Boy #876 - Mike's Build
Post by: A7er on October 06, 2022, 05:44:14 PM
You made that look very easy! I am starting to believe that even I could do it.
Lee
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 07, 2022, 05:00:54 PM
Lee, Kim and everyone, thanks very much for watching this build and for the nice comments!  They are definitely appreciated! 

So next up is the connecting rod, a part that has plagued me in the past.  Let's see how this one goes.  I thought a LOT about how I'd approach this and what my OoO (Order of Operations or Order of Oops) would be.  I started by making a 3D model of the conrod in Fusion 360 and generating a drawing that added a few coordinates and features that I thought would be helpful. 

I started by cutting and milling to dimension a piece of 3/8" thick Al.  I didn't show the operation but I stood the stock upright in the milling vise and drilled and tapped qty 2 6-32 holes with clearance at the top as per the drawing.  Next i made a couple of bits of brass rod threaded 6-32, again as per the drawing.  Then I used a slitting saw to cut off a piece at one of the stock .400" thick AFTER the holes were drilled and tapped.  Next i fastened the two pieces back together using the brass studs I made plus a couple of small nuts.  Here I've placed the stock back in the mill and found the center of it then I zero'd up at the right end and drilled center holes at the big end and small end locations.  Here I'm reaming thru the small end and you can see the center drill mark at the big end.  Doing things this way should assure that the distance between the hole centers is as accurate as possible.

(https://lh3.googleusercontent.com/pw/AL9nZEVMzkxjAWRQRRONMNZ-1qdmt1n8sqUBU9qShpc8GcmQR8_cbHsyrfecDmIgynnARWCuHgAOlpMOW2jlbAVbZG4e-Zu4_X8shYzl4KJFdmH2foqu4uGnNf7HyzVQUOR8XbymY77Q56RidN9TuSiVQYP2Ew=w784-h1041-no?authuser=0)

Next I moved back down to the big end location, drilled thru 1/2" and then used my boring head to enlarge the hole to .5625" as per the drawing.  You can see why Howell specifies brass for the temporary fasteners.  You end up cutting through a portion of them.  Also you can see a center hole at the end of the cap, the purpose of which will become clear shortly. 

(https://lh3.googleusercontent.com/pw/AL9nZEWnQcyQRJS4ydOYwcJmflMAhInNmHI6cWPGG1O7M4uCGsLdXG7uiLBkFcZNFTBNMi4_imEnav9iDn4TwmZCuBdt2BjDykORgkMZEGhflzyeUe8hYiAb7wMY0AXPX5kNNPCdTzgbKSWy2VFGBJ4Q76PfLA=w784-h1041-no?authuser=0)

Then, before removing the part from the vise, I milled some of the thickness away at the 'top' of the conrod, so that that feature ends up 3/8" x 3/8".  Wot you ask, is this for??  Standby!!

(https://lh3.googleusercontent.com/pw/AL9nZEUL2aN2ffJRgImb2MpB1YZNm_MIWFLtxb7tVtrNmMuKmAg9D7o78yFwGCBiQbRFeDcNlcgVjNOkqEDFKOP-AaaEskXgpbmU4-akCg6LwNmhv9gi3US18Jzt2thYOjNbr5AbfomjBTTXuFfgbUPif_Vf6A=w784-h1041-no?authuser=0)

And here's the part back in the mill vise, repositioned with some Al packing material on each side of the conrod.  I started by locating on the big end hole and here I'm using a 2 flute mill to create 4 holes that will form the radii for transition between the rod body and the ends.  Doing is this way helps subsequent operations. 

(https://lh3.googleusercontent.com/pw/AL9nZEXZPb939YdgZN_4oPU7uhmIIIBQ9qKSzSxYHf1Y-WaPjLOadywAxWO19BHG0w-9NB_2yjoipDuEkiUDv-ZuHaHG_nszB5cY0uBQgjR_6IQN4-8SkShyXXRJDh48wVe8f0rxfgPBMgaZp-wYU1-BF5np_w=w784-h1041-no?authuser=0)

Here's the conrod laid on the drawing I generated where you start to see why those holes were formed. 

(https://lh3.googleusercontent.com/pw/AL9nZEXKDLEhmqJTIj6Sp1xtEm7NL61l3896aKuc9wLbrqGvoindX_XERWguWWQ-ckWSl0qwFUNu-UeIM0LAdUmNHQoI1eO6nvcu6ilLSb0zKpmQqWJDAormSCp98_iumMOmVrLIs0xWg-UmowHsRsqMygLTvQ=w1224-h922-no?authuser=0)

Over to the lathe with the work being held in a square collet on the mysterious feature formed earlier and being supported by a live center using the small center hole at the end of the cap.  To gain access to this area, I used a left hand tool and had to place it at a bit of an angle to avoid interference with the center.  I keep telling myself to purchase an extended nose live center, but I've just not done so yet.  The sole purpose of this exercise is to round the edges of the big end of the conrod.  I don't think that this was strictly necessary but that's what the drawing called for, so i did it.

(https://lh3.googleusercontent.com/pw/AL9nZEXUYYEJRuVK1BNgeUtbwUCmKzN8ByZ6zDb6ogPXQA7Yrh2bGmJ66ZwxshnUu3jDT-TdJeIAx3LGD9WS_jb5PVcx9MZjCAgTxZFDktIqW7GuDpPzBJY7q3THH7DdeJxYqJqlRwPM9khge_-csqFqcrUjBQ=w784-h1041-no?authuser=0)

Here's the part, back on the drawing after bluing it up and scribing a couple of reference lines on it.  I did this mostly to keep myself sane and out of trouble for the subsequent operations.

(https://lh3.googleusercontent.com/pw/AL9nZEV4O-uFZ0BK1RxCbMEDGnCcB5rc_dTpY1LhatnlliKFlsd_KCzkj_D1bbSYjk5WXVLWQcxN5gUt_bbb3flKMw2QQMJFgpVpv_0rIb-j_KANe6naf1RiTjy3xF1OfVFS-1UCts_mMvj-LTpAhHXtK_Pfxw=w784-h1041-no?authuser=0)

Next the part was placed on my rotary table back over at the mill.  I made an alignment pin for the small end and centered it under the mill spindle.  Here I'm using a DTI to assure that the part is aligned with y.  There was no other good way to establish alignment in y that I could think of. 

(https://lh3.googleusercontent.com/pw/AL9nZEUdud1w0-Y4p-9WRwFhQxMTXypkFzg5MCbe2gVDWABH5zTquqZRvoZ5aFhEA2ogH2UNdTsl7CHaAemC8Fit_ocPPI1dsCLCc6KrF6rW_kqUkgjfGGK_cUfXPZjMN7YXzJnGepaRFJ4qdVDop4BORu-jeQ=w784-h1041-no?authuser=0)

Howell doesn't specify the angle of the sides of the rod on his drawing, but from my model and drawing, it's 1.66 degrees.  So here I've rotated the table by 1.66 degrees and just for being double sure, I used the pointy end of an edge finger and traversed the mill table in y to make sure that I was close with my rotation.  Belt and braces as they say!

(https://lh3.googleusercontent.com/pw/AL9nZEXKQ3kqHVgbboWwXLmh4mbqw0DpBqWxS7xCaaxsZ70gJ3mb_H1d4idw-zpHVh03GJkPqGUb9vRto_v9Aw5ASwF5pmQdM4NNcQqOjg4QThHRnTnD5utCTq2HsSz2INTG35-Emr_edAATmodo_5PcXffKjQ=w784-h1041-no?authuser=0)

I'm not showing all the various moves and repositioning of the part on the RT, but you can see the end result.  The holding feature was removed from the small end and the rod body now has the properly angled sides as the drawing calls for.

(https://lh3.googleusercontent.com/pw/AL9nZEUrn4ymmn8JDJZxMmYU_YSPTHgstszs3rDqfgDm0tBqVYpPAxONckXyXkgiePjEiyaBn5k0VSyHb4RfqsO-DtzI4roKlkaNHAFJLndT52faLyx1YiqvDIuA5sbzhDxosC9Uh0I6nh72DZf_SPzd6amIDw=w784-h1041-no?authuser=0)

The rod body needs to be thinned to .250" from .375" and this requires the RT to create the round feature at the small end as this pix shows.  I flipped the rod over to do both sides, but I don't show that as it's exactly the same as the first side. 

(https://lh3.googleusercontent.com/pw/AL9nZEWqsDeeZAeG1vtw6TZKKUb_5GBgMajJoEIuM3tVLsfdezKAwzhkRtwZp0AQJDy4b-DQsWVRqWeCzAdrukB_o3n6vpM5-N-wugqNse9T9dcTOLhpkrXd4N83d4TqhlI5bUHhPsN4H29qvKe4R0t3xtKXqA=w784-h1041-no?authuser=0)

The conrod on my small mini-pallet about to be secured to it.  I secured the small end with a bushing sized to just slip thru the small end and fastened with a 10-32 shcs and a washer.  You can see the width milled down on both sides near the small end.

(https://lh3.googleusercontent.com/pw/AL9nZEWOKThMIqFaDLumWZhToGEGgqnJmfOCTMu_ySlBjnIomRpIYaPT6PJjd-2zNitj1DmppsnpfcKAIEQS-R4-WFhXtV5FUs4J5IihRwEI2yZwgMEVd1Bm4f16UaSyByfXR0wHM5ndSHNiS1bNqA9ERPUs0Q=w784-h1041-no?authuser=0)

After aligning the rod to make sure the cut was straight at the big end, I commenced milling the rod body on the first side, being careful to match the depth of the cut around the small end.

(https://lh3.googleusercontent.com/pw/AL9nZEW6Y-1jqnU7kDx5mZ_teoF1Nk3vd8t_JBDYjguz9Hi8bi1N2uwYTcOwmtB0WiZvrrYG-56ew61ebsR7Gg4yyS_yf6LPeG8kDl1UAK5lln-Se_WsDeTWLZHRtemMdXe9QfEbv51yY8cX5j9ThKTdN92S2Q=w784-h1041-no?authuser=0)

Doing the same operation on the 2nd side, but this time with some AL packing material under the rod body for support.

(https://lh3.googleusercontent.com/pw/AL9nZEWM6j-HIkeeOrSPl4Vlo6w62wBGu4o8TrpVRjA0CXygsV8KQjb_GDVt-qKvngfMEQGFviefLXrQk3eGY6XgNpihc1vkEnbRlui1FRXwMiPtrglWWoKpaWCP2dBhCrLHGPE7ag79nvXvbIr74J2rMMCdSg=w784-h1041-no?authuser=0)

And here's the rod body in what I'm declaring to be the finished state. I don't personally like the recesses on the sides of the conrod as Howell specifies, so I simply left that feature off. 

(https://lh3.googleusercontent.com/pw/AL9nZEUp_VLf4saONa2xRBg86fwsyTzbBOBvGgsxYsxmj5JTivQhe-J4pMtGd1EA5qYxVI_pqspgDwFsyH3WThLDsNcqSwdlIg231gs2O7wnhyhw6NVBBvGSnfZWbYXQEGn_zyaNrvYuZ7XCyVOUVxa3BGtSSg=w784-h1041-no?authuser=0)

So that's it for the conrod body but there's much more work to complete the assembly  but I'll save that for another post as this one is getting quite long.

Enjoy!

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: RReid on October 07, 2022, 08:20:04 PM
Conrods often take a lot of work, don't they? But the end result looks so cool! Great job, Mike. :cheers:
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 08, 2022, 01:42:25 AM
Ron, conrods are indeed a lot of work and the work is not finished yet!  In this post I'll show how I made the big end bushing. 

First I took a piece of SAE 660 bearing bronze and mounted in the mill vise and cut in half using a slitting saw.  i previously turned it round to .75" just to clean it up a bit. 

(https://lh3.googleusercontent.com/pw/AL9nZEVHTQm9S6w-1znPS7ikC5Komyw13p85eHLSoDaXOJEvz2UgwSfEzLKg0A-PlOSOR8CBmWH9XD8eNFUl9VdfC_uhB-V1nP1Lwtq4qFsc--mAlzIzIavL2m9T4ZWVMj34Xj8rtOywT3_ZuTCNlF5CzlU5fg=w784-h1041-no?authuser=0)

Then I took the two halves and smeared a liberal coat of this tinning flux.  This is the type that is for lead-free plumbers solder and it does have some finely powered solder in it that helps solder flow into the joint when heated.

(https://lh3.googleusercontent.com/pw/AL9nZEWy3NDCgeayM5jo4LFONGCSl3BLZBNB6meK6Ysoh2II6eee4TZIzwlyaKkRyKg3fKaaHZbtUh6VwaM1kFINy-l_B_GeflsfIhRxZmzS-bhCpYhhjhV3jRAmV0ZZmfPeFHbdGXkjNq-RMgZTRDoI1Dc9Kw=w784-h1041-no?authuser=0)

I bound the two halves together with some 20ga annealed wire and then heated the assembly with a plumbers propane torch and applied some Harris Stay-Brite solder, which I think is 4% silver content.  The solder flowed easily into the joint once I got the halves up to temperature.

(https://lh3.googleusercontent.com/pw/AL9nZEWWQMb8G5gimNyi6jD76wCjLjUygvhXFIDoVpGVn5KBbc9TB_x1EIPjYwX9urc6DDA1RRzciqy3dILGVEIqkxXsIGzgssqK07qWTC-Ul3Ltfh1R2PqvCB-Fhc4xmKvWbp70mtfbqf_dW8-P49Oj7wiOPw=w784-h1041-no?authuser=0)

Then it was back over to the mill to turn the OD just enough to get it round and so that it would fit in the next size down collet.  Here I've done one end of it and I've flipped it around and changed the collet to do the remaining end.

(https://lh3.googleusercontent.com/pw/AL9nZEXgl66rLFMgewrGbeG6btDySoozE3SS_81qRuKSHN5OjAACwT6sJyhOllhlTeTyO-cpZ5-Y8bLcTfdkig8F9SlxXcI8URnpri6RY-FDLnLf-xMFdeUQK_1Fd0EyFOUuS3aoy6Myp0JzMvpVNoG2wkyTtQ=w784-h1041-no?authuser=0)

Back to the lathe holding the part with the excess material and turning the recess in the center.  I also started the cut to indicate where the 2nd shoulder will be in order to check the dimensions.  I used a 2mm carbide parting tool for all this work.  That SAE 660 cuts like butter!

(https://lh3.googleusercontent.com/pw/AL9nZEUCkg9ceOq28fsg0G7xySS4Loic6om4Lt8F1_Bud1OI9RN4IGjQ1uN8jz5c2dgoECOoS3yUtLFnZGsOzbdiE37ZxZ4jOdhsZPX6bFIhMI0-pWiVBm0Mz3q73yH7fb1ILhsyvUB6OHmPpsNbQknfBJVAtQ=w784-h1041-no?authuser=0)

And here's the part on the drawing with the first stage of lathe work done.  At this point, there's no hole through the middle.

(https://lh3.googleusercontent.com/pw/AL9nZEWQoO7-3Sgw_bzGlrejH0hRBEhWO2gzeEh2xRvWCd5MSYsvQzWq1BrHeaTQeC0UDGrVnWY9xuuaAFgIty08LrICikKXfBkvyQpXR__WUizdf99B7KQwIKSfbPY-5UIQUCzvCIOcLJXrvs6fz5ocw0vVZA=w784-h1041-no?authuser=0)

Over to the mill with the part in a collet block.  Here I'm getting the part aligned at the solder joint in order to mill a couple of recesses in the sides of the part.  Aligned visually is more than close enough for the subsequent operations.

(https://lh3.googleusercontent.com/pw/AL9nZEX0QOwSXffS3NRVD1JnyNIL9jN648Mxnc8qKh_KAgCRdaOq3v02w1keC0dUGZlSI7aWm-sLxIoApca-1zU80RP8CsMp6tVdJrn5dp4a-N7kTqlBskMDgjeMXtfe9E7rA7EKgBreA7erPTXsFIBYlkvJfQ=w784-h1041-no?authuser=0)

I didn't have a 3/16" ball end mill to create the grooves on each side.  That's what the drawing calls for.  Instead I used a 3/16" end mill and walked it in on each side to create the recess.  This method work perfectly fine plus I could do both sides without repositioning the collet block. I had previously found the centerline of the part and had zero'd x at the end of the part all by using an edge finder.

(https://lh3.googleusercontent.com/pw/AL9nZEW42iUu9uv4gBVxYrbcKDfAofHXz1B8eEP-8bEZhydcuDfzqxczdBsPe0KSTjM-4F-SEixxbgb3YqDweWD1lx0wLur4EpaIY3dHkqYJW3ducaRSfgY__B5mY8WomjMShIag6QDrid7F7miG06Ov0YLYag=w784-h1041-no?authuser=0)

Then back to the lathe.  Here i drilled thru the center and then reamed to .375"  This isn't the end of the story for this bore as it won't actually be round when the part is separated into halves.

(https://lh3.googleusercontent.com/pw/AL9nZEWnRKLW9U1wjyVCoiEUZ2jgR3aclOCFBU1OF2CNC9gnu-E05-Ahr9AV9koBHS56Zx_KHmzGOyqArM56wXNe5xUvGvCvMoumyv2vPVN32dw8v05BjLaCtAV-qEYbUhhqdppLaYoFxXLEcKAtxwzMLsrt5w=w784-h1041-no?authuser=0)

I didn't show the parting operation but here's the results after parting off.  You can see that the solder flowed and bonded each surface completely.  You can also see the temporary studs used to hold the conrod together for boring the big end hole, just for reference.  The 2 halves actually came apart when I started the parting operation as there's so little surface area left at the solder joint. 

(https://lh3.googleusercontent.com/pw/AL9nZEUtVBOzZt7IFspf7StNThJdVu9Er2vyKTm24W1u3qWEvwBy-hUhT4fsTwF0h8ADFmWtAdZ7Sfwq9-8bEZN27OkXzmwo9wDi72ayFLWbsCPkN96YDysBWWnMnCLO5fprdKvIYsGpMiwX4Jvv3_ZvqkoO0Q=w784-h1041-no?authuser=0)

I spent a bit of time deburring the halves and sanding the joint area clean using some 400 grit sandpaper laid on a small surface plate.  Here I've installed the 2 halves together in the conrod big end and centered the mill spindle over the big end hole.  Since the hole in the bushing is not round and is a bit undersize, I used a 3/8" end mill to clean up the ID as shown.  I figured this would cut true vs a drill.

(https://lh3.googleusercontent.com/pw/AL9nZEVo4RneFF-34FxPVSsZ--HB_EAe64jk5PQXIXW5V8kvxbXvOmI3XSCVBWHWq0isrH5khtH0KrXVwmoya6PwxAsn5UjD_pXBN2OjW1qy2lMErE615rIhIR0or-Plk5GnqJM88PgMAnKC2QnqoYipfw7MPw=w784-h1041-no?authuser=0)

Finally I reamed thru the hole .376" using a .001" oversize reamer. 

(https://lh3.googleusercontent.com/pw/AL9nZEWdT8pO1eGjCVb9v53FGM7ktTl93dweZeS5KVWzn6tTAzQ4tHkg12ncQvo1Cm2AvQokKKvqs7sWxV3aDbPHES2BKcU-XNiH76WPTjW9sE_sLbRyWfkup1Q4VUXIzoM7KOT5SEGR5yPYtYWp9gIho1fcBA=w784-h1041-no?authuser=0)

And just to prove it all worked, here's the conrod with the split bushing installed assembled on the crankshaft.  And if even rotates!!!

(https://lh3.googleusercontent.com/pw/AL9nZEWnVD5mZPBzr0zB2f0Zhh4BpZSMD71l0J4AmQfsiJm8qBh6sbxkpRpcp-qsWJF8hrdNNYB2kqFJ0XMB043oL-HqCTmTtLdr4Ebye5B0bPteCS7xKvuRn3w_kGf7CeolFE38AXq0rbQx1omBlnj3HYudXg=w784-h1041-no?authuser=0)

Making these split bearings is always a butt-clenching exercise for me and I'm not completely happy with the process I used.  One of the issues is, is that the OD isn't truly round when you do it this way, but it is close and it did fit within the conrod big end without difficulty. 

If anyone has any suggestions on a better way to do these split bushings, I'd really appreciate a description of a better method.

Anyway, another part done!

Enjoy!

Mike


Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 08, 2022, 09:51:37 PM
So at long last, the conrod is finished!  Here's how it all happened.

First, there is a 1/16" oil port to be drilled thru the big end into the big end bearing.  Here's the setup using a 30/60 angle block, centering on the y axis using an edge finder and visually aligning the drill location in x.  I placed the hole just in front of where the screw hole for one of the conrod caps breaks through.

(https://lh3.googleusercontent.com/pw/AL9nZEXRE-r51Y08QYkYmmToQa_tSKyLLHXRlzuFNwSkccjxJzr2XLGCeHyAr-flHHECtMl0vKug9qL9j8is57_Jna2iFe9_Bfv5aPMGNecOqrIsWO4A6cg4YS7x9KmrzaBv-DuwkB7A-Lvng5Pdobiq2nVZkg=w784-h1041-no?authuser=0)

Next I made the wrist pin.  First I cut off and then trimmed to length a piece of 1/4" drill rod and lightly polished the OD to bring it just under .250".  Here I'm drilling thru the center of the pin with an 1/8" drill.  I did first center drill the end.

(https://lh3.googleusercontent.com/pw/AL9nZEXpdlbAb0cUTlLfhMyHvwNii9BBS-hHHcGqNqeGBgeyCrBitHouBwojmyuN5wlGFOWLEoKbpmFSp1J0jnwHgq4Cfj13Aq_NyOJyQETcCY401YmEArymrFOeDj43OuYPteHRLWpWyvcFFzUcXOnLFG5tWg=w784-h1041-no?authuser=0)

Then over to the mill to make the 2 flats specified on the drawing.  These are to provide a landing spot for the set screws that secure the wrist pin in the piston.  Simple setup.  Just placed the pin on 2 parallels and tightened the vise.  Location was determined by determining the center line in y and also barely touching off the top of the work with the cutter. 

(https://lh3.googleusercontent.com/pw/AL9nZEVGpft6ekgSZe92hbZ3cSujwB2XWe-T64c6s2Lla9EMIXMGX7aKDtPmKQt4q7POVnHzQmFJ7y7iR408GSZV2tExJ57F_vDMDvvT8HBXyMJ_RWTmd62TGmt85ZMabOrOAKXBWfO-fzjckq1xpcuyuIyxEw=w784-h1041-no?authuser=0)

And here's the finished wrist pin.

(https://lh3.googleusercontent.com/pw/AL9nZEWgcfdSzimipPCTprC47wg6PXILlZwWE7wY6ARctcGZewYCxFNnDj-lzRqdVt_BVUku4jgQpUoein2P-Xj94ZVydJ69A9AMIBp7nTgW-_leQfLIpdIeJg0TjUSv_Z4J4Z29zzIfYhxK2JBDuE5vbK0Blg=w784-h1041-no?authuser=0)

I didn't take any pix of the operations to make the wrist pin bushing.  It was simply turning  a piece of SAE 660 rod stock to 5/16" OD and drilling/reaming a .250" hole thru the center.  Here's the finished bushing laid on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEU5bHXxL7STZ14LjsVIznKFrVvaaUkZEiDZtGS7yWmdVWJIu2igA-vRsrI2diXVd1qq0JjshQyr226PufuJddykmzwv8ld_ho-ND6RbjD3sq-ETd6Aqb8oVN-mJ4LxOYSs1etL8RL_YM04wZYlXUUcGpQ=w784-h1041-no?authuser=0)

Then I slathered the bushing's OD with some Loctite 638 and pressed it into the small end of the conrod.  Note that the bushing is slightly wider than the conrod body so I spaced the conrod body off the press anvil with a feeler gauge by the required amount.  I didn't take any pix of the pressing operation as it's not at all interesting or exciting!  But here's the assembled pieces.

(https://lh3.googleusercontent.com/pw/AL9nZEUjoRDRYonmJEjceSHhB1LmKHYaJhP69Xwk-kVxov2PCHhxEInOss236cc-r-Ts0mpP-L73dbew5Wz4sgsBoIH3IRZe1cn9Bjc-O6gCOq7ZW4Y92wg6I1yxN-utHzV_YmgGr95tSZdB3UmRmQbN2h7ZOA=w784-h1041-no?authuser=0)

There's one more operation required in order to create an oil access port for the conrod small end.  Here's the mill vise setup.  Note that I inserted some Al packing on each side of the conrod since the ends are thicker than the middle and the ends are different thicknesses.

(https://lh3.googleusercontent.com/pw/AL9nZEUEDo6OyojfpdRKFy60Hz5UB_p0jpfHo-KAYSVw_UW7-ueghqZJoSUM62Fr9Klnd0pTxF40wMBewJaPPyv3vPOV5H_3XdYTRpd-0QETJqsP1ZhGGDJm7_NnSWUdHtkhGo4yp_QLsuVNdIzYyUh5ck8nJA=w784-h1041-no?authuser=0)

Then a small slot needs to be milled across the top of the small end.  Location was determined by finding the center line in y and locating x from the small end top.

(https://lh3.googleusercontent.com/pw/AL9nZEW8uaZrxJmakOnPqdKK9mBGcCg26B2uPfy4HTx7MQv-mwR-wriJfjn3Q-tPenUi9XbRr_k8JTHrR-zaCJpoyexGvDUHs_VQDCSxux7ndaeyMO2HXeqCZZ8VgyvLSLKlfwSA45Uy6RnRe1tjQMMWRCWs5Q=w784-h1041-no?authuser=0)

Then without changing the setup, I drilled thru the conrod body and bushing using a 1/16" drill. 

(https://lh3.googleusercontent.com/pw/AL9nZEXQiaawOl2cZMmAUmhDm-kypND639bm-wdacWkYtdjIuFZbUXJCnFn1-sys48ohzVCDHkcu0rOH9bDAoDqrgP14pctRUoYNpE-O0hsNLXjCRC5vXD0auWTxcdSQx7JmrMwZmFD_71CRWJPGusm0hN2Wng=w784-h1041-no?authuser=0)

And finally here the now completely completed conrod!!  There are indeed a lot of operations to make a conrod and I think that this one came out at least OK.

Enjoy!

Mike



Title: Re: Farm Boy #876 - Mike's Build
Post by: Roger B on October 09, 2022, 04:40:18 PM
Looks good  :ThumbsUp:  :ThumbsUp:  :wine1:
Title: Re: Farm Boy #876 - Mike's Build
Post by: Bearcar1 on October 10, 2022, 05:34:17 AM
I am enjoying watching your progress Mike.  :ThumbsUp: :popcorn:


BC1
Jim
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 11, 2022, 09:02:50 PM
Roger, Jim, thanks for watching this build!! 

I noticed that my conrod was getting awfully lonely sitting there by itself on the bench.  It definitely needs a piston for companionship!  So this post shows the piston build.

I failed to take any pix of the start of the piston over in the lathe, but i simply cut off a bit of 1" round Al bar stock and drilled and then bored the two internal diameters as called out on the print, plus I touched up the OD of the stock with some Scotch Brite a bit.  So I'm showing the start of the work over at the mill.  I mounted the stock in a collet block shown and drilled and reamed .250" for the wrist pin.  I found the location by centering the y axis and locating the bottom of the piston all by using an edge finder.

(https://lh3.googleusercontent.com/pw/AL9nZEVP_uV8QYvUj_ISguyfrTE6Dfenpl49K0PHCLkcZd1RX3dmJrEikWC5GwrE9PTi60wbBBS9cR0zDU8k66vpaz1s5z4RiWQaouKNQLLCqgzijuQ6UEy1Rpd14hcW8B7exaBC6cZbKGLBgUsxkKtWxplxYA=w784-h1041-no?authuser=0)

Then I rotated the collet block 90 degrees and drilled and reamed the 1/8" hole for the oil tube.

(https://lh3.googleusercontent.com/pw/AL9nZEWckmfRUsE4RSWYt6FpswBHFSzFO9hFv47fo56t0sY9GD_V-qpJGbWgRSrH9Y3OWpYAbtlPf0vAW9yP-_X8oYhDVT2_Ah3s4NxDmEvzlIGbeOB15NnGMSlTgCIijS05XyinalH4Q2Sop9SaOj76iOd-jw=w784-h1041-no?authuser=0)

Next I stood the collet block up in the mill vise and make sure it was vertical using a square.  Then I put the mill spindle directly over the center of the piston using a DTI as shown here.  And of course I set the DRO to 0,0 at this point. 

(https://lh3.googleusercontent.com/pw/AL9nZEWRpGzrRnjWtmZH24PvovufGA3qNRcdbBTgvxJ0EwQZZO59518VNziESSScYwc59RLFkpM15KMGOP5ApJSIUnCz5PNjfgIBHJGgriLdSAKqb6o2lxRLzgOjUrVh2bj1CJ21NRBf7CykETg1bmdOkzFReA=w784-h1041-no?authuser=0)

Then using a 4 flute 1/2" end mill, I plunged in and made the slot .980" deep as the drawing indicates.

(https://lh3.googleusercontent.com/pw/AL9nZEXLDNPy_qLLCUaXeECWF7y400N10622BuPOrpNbxXrFA6kpYohwpcovOjBWI9GDVWg28nMowuAAcxxFqKPTN4_-Hw7MJeRWPbEi-1aku0LvwopO3HWXzHOuxq-NYSAev96QQs08IWVKlNL8yTISgk3mgQ=w784-h1041-no?authuser=0)

Next was drilling and tapping qty 2 4-40 holes that will accept some set screws that will be used to secure the wrist pin.

(https://lh3.googleusercontent.com/pw/AL9nZEVb3FI9oRDKgg1nQmTVRcwD81LlwpCYyQC8NWsUsKyht0tjWjLelhmxDS4bAKH_ijOWpo7_qEMQScz13aUvCWCJdd2GftZUDByfqpYp683Ih2dfLyysfvb5LqvHM3-GcbEziFekyVuiMn98RQgmJT7u6w=w784-h1041-no?authuser=0)

Then back to the lathe, using the 1" collet to create the o-ring groove.  I used a 2mm parting tool giving a .079" wide groove which works out fine for a 1/16" nominal cross section o-ring.

Then I moved over and started parting off the piston from the holding stub using the same parting tool.

(https://lh3.googleusercontent.com/pw/AL9nZEVfiCCq0E_ernLlAX6XThZBJrHV00XgexdecNjwer_Elf-jG01tUxPraoXQUm_Y2o7rWaLpqKMnxwFTUE-bl3gLqmf_XRLpWXMzfE_gSUTgQNiIB3C52y_-TmBfb8BOddBHoi1dMJ2h37PPP0jns09U-g=w784-h1041-no?authuser=0)

And here's the piston on the drawing.  I wanted to point out the calculations that I did to determine the o-ring groove sizing.  This method gives much less 'squeeze' or compression on the o-ring as compared to standard o-ring calculation as given by Parker et al.  This calculation yields about .0025" compression PER SIDE on the o-ring or about .005" squeeze on diameter.  Its interesting to look at JE Howell's drawing in detail.  He actually sizes the o-ring groove for a nominal 3/32" cross section o-ring but very interestingly he UNDERSIZES his o-ring groove by .021", meaning that he puts NO compression on the o-ring but I think he depends entirely on the pressure activation caused by combustion acting on the o-ring to form a seal.  At this point I'm guessing but I think his method may produce acceptable compression on the power stroke and almost no friction on the other portions of the power cycles and when coasting between 'hits' driven by the hit and miss governor.  But we'll see what happens!

There's one last thing to do on the piston and that's to add the oil tube.  Here I've drilled and turned to length a small bit of 1/8" brass rod as shown on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEWcph03HNo1qVaIp6TIvpt2vYOVjpQT7KKiPu9qakQ7A2uP9OdIuRgRTDg9dbzo1XEcLb5PaXY6OBp9XCRmBqI0VbvTj-wZ7P65-klKl7hmocJtjeMKOQLcr339twoIdh0pPrMRymjWy_7447ATdEldcA=w784-h1041-no?authuser=0)

Here I've pressed it into place in the piston using just a small bit of Loctite 638 for extra security.

(https://lh3.googleusercontent.com/pw/AL9nZEVJUcu9UjBdDnzY1llyVsadvdtUHLt27NB7YHn7PeDH843pjezWSk9xBXedLHJxgC2pJbdlbf81ZMNsPdlz061fzw35MN2ZM-phKSwDWNrlvFNMnxgaZSABj6XupTyCbzL7HGPS4hbHQjHoLlmWG6M2QA=w784-h1041-no?authuser=0)

And finally, here's the fully completed piston, shown from the bottom with the oil tube in place.

(https://lh3.googleusercontent.com/pw/AL9nZEWf4wMIWKjEjY6snkNpmszipomSa7lkHIjlfJueZKlJW7FlihEY6s8XKeik9ze9LJF5kvqQG3lwS4rynrwTZmh1y6DNZV0CNv8MYfHlE72BzLtaWPO71XY8UOZN2Stgo_tg6AEarTVSp2qMaLez3m4SZQ=w784-h1041-no?authuser=0)

And that's it!   Now the conrod has a friend to hang out with!

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Don1966 on October 12, 2022, 07:45:08 PM
Awesome work….. :Love:

 :cheers:
Don
Title: Re: Farm Boy #876 - Mike's Build
Post by: Dave Otto on October 13, 2022, 01:28:07 AM
Yes, very nice!

Dave
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 14, 2022, 12:28:43 AM
So with the piston done, we are now truly into the small, fiddly, tricky bits.  First up were the valves.  These actually went much better than I'd expected as the parts were a bit larger than the valves on the Webster and Upshur engines that I'd previously built.  Here's how I made 'em.

First, I parted off a couple of disks of drill rod a bit thicker than the finished valve heads would be, as I recall about .110"  I'd just drilled and reamed a hole thru the center .126" so just a bit oversize.  Here I'm in the midst of parting qty 2 disks off the stock.

(https://lh3.googleusercontent.com/pw/AL9nZEXBsZmnxXWzgUVsrFVV_ajPxNf_3adKmz5WaZiTwbZn54gjDvMriwI2LULrH5FXHj2LoKNEjIQAxQJhNxeCqh77nQK_fzOoyLxCg1dvtlGBa2pXDyIAxDQ_XkIIhgAYvm22DtqmhpUbOxnm9HCmcKIoaw=w784-h1041-no?authuser=0)

Then I cut a couple of pieces of 1/8" drill rod off and turned them to length and placed them in a collet block in the mill vise and here I'm drilling a 1/16" hole thru the end of the drill rod.  I found the center of the collet block in y and found the end of the rod in x for locating the hole.  i gently touched the drill location with a small center drill and then cranked up the rpm and drilled thru.

(https://lh3.googleusercontent.com/pw/AL9nZEUZYf-fjpsgH-R5SccoygzWSBHBN_1PMf9Ki4K2wFxD5670mAXcjbszClI7WJzt9x_IV7KTZeW6ZSodEnMXTGFItCyQ0s6ZsxtLnp-XaMcfFjY0zmRahmqyQluQxgrEZIxWHzSBpFiiN0EfPdXsnx_BjQ=w784-h1041-no?authuser=0)

And here are the parts in their intermediate state laid on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEXw-5gc5YHDp4pwmVJ6ckHDherl6NcUMBPUhPsWGEvX44ZE_dHjpPe5all7QmPRp2fYLRiahInJFy86CnZrbbGIxr-ugFPVm2SdwalEfGqmeg6BEa0PBL6muvB7dKIryei-PgXqJqvwRTPhyDfVg23whg=w784-h1041-no?authuser=0)

Here are the parts in my welding table vise prepared for silver brazing.  I punched 3 small dimples on the top of the disk to keep the parts aligned and spaced and coated the top of the rod and the interior of the disk with flux and then spread a little more flux on the top.  I clipped a small piece of silver solder and laid it on the top.  I find this works very well vs trying to feed the brazing material into the join by hand, at least on these small parts.  I used Harris Safety Silv 56 with its associated Harris Stay Silv flux.  I find this brazing material works extremely well.

(https://lh3.googleusercontent.com/pw/AL9nZEWo4A5qVQhb1DRuCuOta6IEopR1jyb6KGsOK6VWzJpWx03hDyKSqfa-UjOZqaF7yS2C641CshLLwur4tOo9Y_lrJcH-ov79fWCNAqfm2PHGDjqCkzUZc9a_kt4SZfFqC_qEOowhLnXKcoEwrSVmeokCGA=w784-h1041-no?authuser=0)

And here are the valves after brazing and after cleaning up the top surface in the lathe.  Note that there's a complete bond between the valve stem and the head. 

(https://lh3.googleusercontent.com/pw/AL9nZEVLX3nsickoRjbiCznScOpk6F5sUqOOZ0ijTv2EiZIns4h902Rl7eC1XSyl8wsNgTdcIuhj1HGuNDXzWI4FiswqcZyEOMa1NLfo4-K0RcNeaHz7OEC4kU4g8VQT7BXs8qK3HpUP-0TusYP8IzovmiRzwg=w1288-h970-no?authuser=0)

And here's the bottom side of the valve showing the stem to head interface.  Note that the brazing material went completely thru the head of the valve and formed a nice fillet at the stem to head interface.

(https://lh3.googleusercontent.com/pw/AL9nZEUS3HU5E1pafkbSR1jRjkDl27QpI1QL4TDH1k4HODdOVdnXgnKqx6XiP3LB3liipWh_k5z1n3cwtb3qvY1mn_9O1A2f_-Msosg70qHBvl18noNRuTSaQtXjMnvF2DsGNWpYIYKTZU2ige7xRMPaP-fWew=w784-h1041-no?authuser=0)

Here I'm turning the backside of the valve to 45 degrees.  I did this with the lathe compound after setting it as accurately to 45 degrees as possible using a 45 degree angle block.  I find that the edge of a carbide parting tool goes a good job of leaving smooth surface.  I did also polish the seat surface a bit with some 320 grit emery cloth and some Scotch Brite. 

(https://lh3.googleusercontent.com/pw/AL9nZEWksG27xnegneixBinpQ_R-s5GFaoAYLO2VouJRcpmB34vI7qvGxY1dgx1EQK4sTIEtf3tkCoYTX2WoYcLt_zmHBwlwyEN8R7YnJnLOKaJoTYZnw3AlqLisxLSOdnMDTA9qb33DGNEAGC9JCxM53kPFkw=w784-h1041-no?authuser=0)

And here are the finished valves installed in the head.  They feed good and they slide freely in the guides.

(https://lh3.googleusercontent.com/pw/AL9nZEXyooHu_tKKf3c3Jgh9wCX_cKgnxrPWAHg9BUJMOB-8O4dOB7qpYn9K8S4gahsH788SLqIt-zYLKPGB83_Od6uXLeA6J-QfvL7Zv9jwBsTbLHqterDPGcdfMHw0mp1cWe3TxiBrSnhR8I7IRX6z5SKvRQ=w784-h1041-no?authuser=0)

I do find that silver soldering the valves is easier for me than turning valves all in one piece.  I've done it both ways, but prefer this method.  I think mostly because i can get an exact size drill rod for the stem vs turning down a small OD rod to an even smaller OD.  That's a tedious process to me!!

In any case that concludes the valves!

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 14, 2022, 12:49:55 AM
Since we're on the subject of valves, we'll need a couple of valve keepers and a couple of springs. 

First on the valve keepers, I started with a piece of .50" brass rod and turned the OD over a short section to .400"  Then i drilled thru 1/8" and shown here I'm created a bit of a recess using a 3/16" end mill held in the tailstock chuck. 

(https://lh3.googleusercontent.com/pw/AL9nZEXfVzs9ljtQNahWSqdFWW24D-SA548N6_5fk7i9AL5TV6zCBi3iPIKNsFndsS5zOnvNC9QNHnL_z05NFcFvK5oYZ6wnlNGAG3uEsrucs_a5Imv7Qm08zTiEuIBVEnhql4TDGcT1sTAn1ChEgN8AISVWsg=w784-h1041-no?authuser=0)

Then I used a parting tool to create the small step required and parted it off to length.  You can see that I turned the .400" OD long enough to make qty 2 parts.

(https://lh3.googleusercontent.com/pw/AL9nZEVDHxb93zbtraFRImUNNNvIVoBIlcHwPj0Rt29jerHy_aJyUw6DKfGfPja0Q62FliYKpkEmNb3aQTj7Q1ZAS9pU1Pp6yRcUuii2a5XRH_-L0jXlSbMzLW7tUzxatkf6ju0BnQUen1DGdnHlCQ-x87oWEQ=w784-h1041-no?authuser=0)

And here are the pair of valve spring keepers on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEUaFSq5XlJMIyxv_PHX-ml2NrnR4RK3p-ZdURK0f4auhsyuCU9iuPW1bSHnC3BydJTs_JnZ3v7GPuibkI6IV9W5E-dBnOWcO4EOKzMaxXA1sD1LPiFK_L32zC9MKHP6CJCOhjMGIZSzkcIHLJ3pkDVUWA=w784-h1041-no?authuser=0)

Then I needed to make a couple of valve springs, one out of .029" spring wire for the exhaust and another for .019" spring wire for the intake.  Here's an overview of my general setup.  I make a very simple mandrel to whatever OD that works for the spring ID required.  In this case I think it was a simple .25" bit of rod with a hole drilled into it to secure the starting position of the wire.

(https://lh3.googleusercontent.com/pw/AL9nZEW5KIlvnhPliNcLWzoJwCkhZQ_OORHkvc9FLx8h_cJsWquCorZqkhI5rGwmraBVbe4pFyyH1LGY9evNUNjE8-ZaRy5BAwYwSiE-LpA8xOXyiapkAE5-RubD67BVVH_G--RR9Lx4FclMja-RYGvkbaFO7A=w784-h1041-no?authuser=0)

Here's a closeup view of starting the winding process.  I have a home made guiding tool that's nothing more than a bit of rod with a hole drilled thru the center to feed the wire to a v-notch at the front that guides the wire onto the mandrel.  I set the guide higher than the mandrel and run the lathe in the forward direction so there a fair bit of force to wrap the wire around the mandrel.  I tension the wire just by hand feeding it with a bit of back pressure.  I run the lathe as slow as possible and start without the feed engaged just to wrap a few coils closely spaced at the start of the spring.

(https://lh3.googleusercontent.com/pw/AL9nZEVtulgW8xyTCDfDAaiCGOsJCrZLBxsitrW7I14t0WxxTuxrg3TGybfpHWvFEz9enqLUAkP73f6gYDIp3D-NmqyfgLYrW6Wq4q1rkdCQZpeTmiLeiGAKgAtC0bBxOlS9UtvbQXeq97iY0lGBhLup0xtbOQ=w784-h1041-no?authuser=0)

And here's a spring that's completed but still on the mandrel.  I feed in threading mode and I think I had the lathe set to 8 tpi.  When I've run whatever length required.  I stop the lathe, disengage the feed and jog the lathe a couple of turns just to create a closed end on the spring as seen here.

(https://lh3.googleusercontent.com/pw/AL9nZEX2MfbT6mpPMpuuWplB0Oqgh53WDkeew8qEdOU6OOsNt1aPLbgQdtPNQlOl82gPCVNDxz-Fvjd6Vgv7Shl09hmOJv6HzfWYJJiSkUkIk8mte9-U-B50tdogm2N1sjzu6_8jWGhhcjII9Y5txBBFbnWrCw=w784-h1041-no?authuser=0)

I ended up making 3 springs, two of which are for the exhaust as I wasn't sure if I'd want to use a spring with closed coiled on the end or open coils.  I was pretty sure the intake would require the lower pressure open coils on the end spring.  I actually like making springs as I think I have a pretty good process and with a bit of care they seem to turn out well, although sometimes you do have to experiment with the mandrel OD to get the intended spring ID.   This pix shows all the pieces that make up the valve assemblies plus the spring mandrel. 

(https://lh3.googleusercontent.com/pw/AL9nZEV2qeCIBittvxiI0CH_fb_tswG_ktj74U6Ofd8ZSS_L8ISHWiH1x2vRqRFk8s-MO5lQuvgyQAKBl_Uyv6iHiUZLbo7xE-kvnPoeBi3FERZYEZEi-ET_e6l35IBzVwPnILzX62_xeE_VtRXIA3rxOCzqWw=w784-h1041-no?authuser=0)

And with that, the valve assemblies are completed.  They just need to be lapped and pressure tested, but I'll do that later when I'm closer to assembly.

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 14, 2022, 06:54:46 PM
Next are a couple more small fiddly bits, the crankshaft oil cups.  Qty 2 are required.

I started with a bit of 5/16" brass rod stock and turned the OD profile as shown using a standard GGCT insert in a right hand tool holder.  Here I'm creating the small radius just above where the hex will be made, using a hand ground HHS tool. 

(https://lh3.googleusercontent.com/pw/AL9nZEWsLpiQ14ut8X4PogQq9-sqHwU4-xBq-dfr5UbvZf_Dha4abopd4lq2c0lZJKGv675TWnwze7locN-CVvmMOHh850ItlHgifbJ1dpXbNDQJEemTVYW4pD-XuaNW-lThbMxx_7hYlo0Aru68QwO3OC32wA=w784-h1041-no?authuser=0)

Next I drilled a #56 hole thru the end of the stock using an Albrecht tail stock chuck.  I'm trying to show the size of the drill using a 20p coin.  Sadly I may have to retire my 20p coin and eventually migrate to a coin with an image of Charlie.  Before that I may ask the UK citizens to weigh in if that move is appropriate or if I should keep using my current 20p coin!

(https://lh3.googleusercontent.com/pw/AL9nZEXLiXYyqgGC40R_BfPp3UXFlsIhM4X38XfwEuABsqquwBhvY87VuZhZFEvan6oS5CghtxDYDbRlFL2EPOKZgjIus7jZedpAAKt6qZZ_-itqkN7dJGAIfbGijo3O6XBwdxDIzlq2ExEwDmHgg4L9iAeqrQ=w784-h1041-no?authuser=0)

Next was threading the end of the part 10-32 with my tail stock die holder.  I really like that home made device!

(https://lh3.googleusercontent.com/pw/AL9nZEX7vS_8MIlgwXHIhxSNv1IcNuYCKx6NT461dTJ_eJUgjHXH1TQc-jX0495v4kKT1Z_IK2mteLz37DwayQf8HMqmNPwbJaaYdtEE2UNAFfINY7wtdldnhslev5pydSuKaXXymjjpstQtqywSVfLXgjx3Pg=w784-h1041-no?authuser=0)

Over to the mill with the work placed in a hex collet block in order to cut the 1/4" hex pattern for wrenching.  As you can see I put a work stop on the rear vise jaw so that i was able to quickly reposition the collet block after each rotation. 

(https://lh3.googleusercontent.com/pw/AL9nZEWf38K7TB6ZrEiGVmG0YRAWlNpNvjXAhkC3nFMp-DSp7su2YuT2mnscZB-nj1veVEJDmnKnbOeQ749uI2vq2hLBgnJ8q206UoAjdcnMF9TUNhdVzDI_bWSFii4aZ83StCW5o0_msvjbH5MVHon4Fty7ng=w784-h1041-no?authuser=0)

And here's one of the oil cups on the drawing after parting if off to length but prior to drilling the 1/4" hole that forms the oil reservoir. 

(https://lh3.googleusercontent.com/pw/AL9nZEWisVGJYjYLrX1ezCHVXbCOAE6keVv1DnRx6nAg8jBQ2GoQhRd0uqFf-JoZlLISXEzu35rFqYuIBG0TMxoE1pUToVgIf1z4dG1EHeIzTeUit5ZUOJh697qc4DtWfMQ2nk3x9lmKYbTyG10VK3icNlRW4g=w784-h1041-no?authuser=0)

I failed to take any pix of the drilling process, but it was just turning around the work and placing it in a 9/32" collet installed in the lathe, center drilling and then drilling 1/4" to .400" depth.  All the above was repeated 2x times and here's the finished oil cups on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEUtm-vU5-fGIZTaHOq3RBSUS51JH03GdElJ_UEx5m5mwts2anR33ZX3p0btxW2zt8x0PN4wZhMU4-PykXtao7ytatsqDPgVEXiO7Z-xrgP3ZrD_JzbloRogqBs2D2Z7mN-_ixpIp-aFbBtyBeBIAKBXfw=w784-h1041-no?authuser=0)

I hadn't drilled/tapped the holes on the crank bushing caps earlier so I installed the caps on the frame temporarily and located the two holes and drilled and reamed thru 1/8" .

(https://lh3.googleusercontent.com/pw/AL9nZEUsVpgzqLjBU_rD_BwfBGeu3Bh5wJYMKB20UA6JqDh7PWsyuEbcm2Nz1bCiLzS6UUqH6q1PDP5EJr9xHE_D7x6N4mQIbpWhtmfnF63Fyp3pOjtBgfJX6wR5fTd-iFgDSHUJpOxeBh_v6g-yaM5h1GTDEQ=w784-h1041-no?authuser=0)

Here you can see how the 1/8" tip on the oil cups engages with the hole thru the bushings.  This locates the bushings in place and should help prevent rotation of the bushing, although I doubt that would ever happen given the tight fit of the bushings in the caps.

(https://lh3.googleusercontent.com/pw/AL9nZEWpjGhTLnds_60YU4gQ4hc5-_rmw6tjDmqvtN8ioejSe_FNc473bEO7O80Fyzvx1sL9FSrRNej58mpcPmQ-Lod4H9BpKknBFIc8i34qPvP9zKs5drJ-cB3vKFGCfumqDhHTtba-Q2AbMLGUzUV4lrUmhg=w784-h1041-no?authuser=0)

Before tearing down the setup in the mill, I tapped the bushing caps 10-32 as per the drawing. 

(https://lh3.googleusercontent.com/pw/AL9nZEXmXyiVUQmuWwktw8BCVgiwTxoeDeHw1FGBSwkkjrlSKDx5KsaTCOrz_5gNOeseGd8VGW7Nwy7Vgi3pmBfD25T1WD1YElQXTGBSnRenxMQyCHNHJNJSGslk58SRWumo4K_wwW9AK9pyLEcGckfeGqcK7w=w784-h1041-no?authuser=0)

And here's a view from the top with the oil cups installed in the bushing caps.

(https://lh3.googleusercontent.com/pw/AL9nZEW1RgptA_GZY5QnMU2RDvzFHElky6PKgS__bpqL-_JXNre9rMpwkHCF9lQkyKdmhbXG0d8_tfBtPdMuiQeOdfVKWnh1D0XZg-fcA57R3CZLfqlMArUQ3sND-s8pXdKPDbCtITfTk6xKXx8vp2GtA-JDAA=w784-h1041-no?authuser=0)

And finally here a view looking inside the crankshaft hole showing how the oil cups will engage the bushings when everything is installed together. 

(https://lh3.googleusercontent.com/pw/AL9nZEUgfHm8Qp9iaEpRywunI0R7dxr_KaarfWI9KcaJHqxNhLopmerHxe-XriTqrW_9vfwQwBwTcm7eOrDafiiVpO7Iw1jaDhk-96TU1BKozFEoEqBLziKzHzhVBj2UDdMEIrRTVNKJAoRyxVQOqV-D9Eiz7w=w1288-h970-no?authuser=0)

So that's a couple more of the small parts completed.  There are many more to come!

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Admiral_dk on October 14, 2022, 08:46:57 PM
I like the results so far - and you are right - there is always a lot more small parts than one first thinks ....

 :popcorn:    :cheers:

Per
Title: Re: Farm Boy #876 - Mike's Build
Post by: dwulfe on October 18, 2022, 12:55:59 PM
Great thread, thanks for posting the details
Title: Re: Farm Boy #876 - Mike's Build
Post by: Bearcar1 on October 23, 2022, 06:24:58 AM
am still onboard this ride, Mike, and I am enjoying it alot..... :DrinkPint: :popcorn:


BC1
Jim
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 24, 2022, 09:02:52 PM
Gents, as always, thanks very much for watching and commenting on this build log!  I really appreciate it and it keeps me going!

So, the next bits up are the timing gears and cam.  First, let me give a caution based on what i did and the consequences thereof.  My advice is to follow EXACTLY JE Howell's recommendations on the gears, that is, it's best that you use 48 DP gears, 36 and 72 teeth.  Now let me tell you what I did and what problem it caused me. 

For various reasons I was able to get a pair of gears in 32 DP and you can get exactly the same diametrical pitch that JEH used by selecting 24 and 48 tooth gears.  Both the 48 DP and 32 DP gear sets have exactly the same pitch diameters those being 1.500" and .750" giving a center to center spacing of 1.125"  Earlier I pointed out that there's a minor difference on the crankshaft to camshaft spacing on JEH's drawings, but I did correct for that by moving the camshaft location forward a bit to give the exact spacing. 

Here's what's different and why it became a problem.  For whatever reason, I overlooked the fact that different DP gears, even though they may have the same pitch diameter, WILL have different OD's.   In the case of this engine that only matters for the camshaft.  The 48 DP 72 tooth gear has an OD of 1.542 and the 32 DP 48 tooth gear has an OD of 1.563" so .021".  That doesn't sound like much, BUT it ends up interfering with the governor catch lever and I ended up with a bunch of unnecessary hand filing and fitting later on.  So I'd say, follow JEH's design and avoid this problem!

With all that said, let's do the gears.  First up is the 24 tooth crankshaft gear.  Since I started with a gear with a hub, I first machined it off.  This gear fit exactly in a 13/16" collet so that made things easy.  Here I'm machining off the existing hub and then I bored it to .650" as per the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEUljn6ctnama3O1MICW9hGIisMGyb-thdG-w7eKvMbdSQyPaikdjeWWLJQNr72T3awxc3ubu9HT7vEM1n8In9nr-F1XIXH_rhayP25SLDAVVALWrZgmYe-zHNDHLkUfDuQ9uQxGa5Y-En5YZYszFWi1iw=w784-h1041-no?authuser=0)

Next up is the 48 tooth gear.  It also came with a hub and it was .250" thick so I needed to remove the hub and thin the gear to .156" as per the drawing.  The easiest way to hold the gear with my lathe is to use a machinable collet, also known as  a 'pot' collet.  Here I've installed a blank machinable collet and have inserted the pin in the center to hold the collet at a fixed position and am just finished machining the collet with a boring bar to hold the gear.  I think soft jaws in a 3J chuck would work just as well if you don't have a 5C collet setup. 

(https://lh3.googleusercontent.com/pw/AL9nZEVe8Sm80X7NrgKvUc1ZOSm0udEfo0dlB732uJCSk70W4qgD3Qb0WCtbIXBj4LgNcFORIIFhSUHaJRSZGOQ-ns7w4asVSnLesGdsZqGNtpfRfYI7spKbRNyL8Aof5YYcKI7QQQWeg3_vcbfenLfMdmIihg=w784-h1041-no?authuser=0)

I'm starting to machine away the existing hub.

(https://lh3.googleusercontent.com/pw/AL9nZEVbVzGt95CXvbK2QanWRbUn1J0PrtA-lm7KSN_hvE9IFoTuYCMFr0TKmSm1zkSTn5b14LCHqdQXzLBCpHV1kqDK6IhTqGfsD7kM4wtHDBLDLPYrrWNaJIhWv-4AUymK4jfe6Phr4D11DH3-DD-zsfuimw=w784-h1041-no?authuser=0)

Next i bored the gear to .50" for a bronze bushing and the cam.  You can also see that I've reduce the thickness of the gear.

(https://lh3.googleusercontent.com/pw/AL9nZEW2jsn_TI3A8Bz0BSpFRFHtdZUxJkmPj4_fKQ-ekPk7KLmOpy_AbShNuV7tGup01vshEmBT7KzRbIme2re5oqLO084_jQfSEccYa5iA71-ADMR_52Z73nu4S8qKXiPB_wno3R4-iB6gRNJ5aB5n2HHq-g=w784-h1041-no?authuser=0)

I don't have any pix of the next couple of pieces, but I turned a bit of SAE 660 bearing bronze for the cam gear bushing and a piece of drill rod for the new hub for the crankshaft gear.  The bits are shown associated as they'll be assembled. 

(https://lh3.googleusercontent.com/pw/AL9nZEWIatgXagaE43Hl_qI3LhbcvKSsjoMu3H9l2kR6hzoLvPVnIHkwOuO8WWMQR8yII2uD9IAb4nTaFDga0ryxz_eUhsSlgnr76xxCNFKxk69ulL3Be1Moym7zN87Te4wszvAKox8j_Y5CZ48f0BHLK59EhA=w784-h1041-no?authuser=0)

The crank gear hub required a 2-56 hole drilled and and tapped for a setscrew that will be used to secure the gear to the crankshaft.  I thought it was easier to do it now vs after the hub is installed in the gear.  I simply found the centerline in x and y and used the DRO to position the hole.

(https://lh3.googleusercontent.com/pw/AL9nZEWKKL9GnOfiE99RX_BbsANvLpZodd2IHBU0-iY7dbDiFR81rFLfwzYVtGYOnIP4MkU98r33K6nVLIJ5mrbM2rEj32ILROAC-xtyn0itoqfZ-_HjkCav4SIXolz4mXWwgklWTz99A1kZE4CKTTH9oJJuXw=w784-h1041-no?authuser=0)

Then I pressed the hub and the bushing in place using a bit of Loctite 638 for extra security.  This was an easy press using my old Dake #0 press.  I didn't take any pix of the pressing operation but here's the finished bits front, then rear views.

(https://lh3.googleusercontent.com/pw/AL9nZEXVP4-3tjIsWD5M9wR_9Nr3YhbNclcKBJ94UczfngKyGZT3N_slejdf6G4EbzEAnr4CSE8oP9HYVcvCmP1oDZG-Y2D6pIpt5m3DUYML8K6k1Y57Y_DMD91OwsDGZ5otPbklyFn4KMCzCheUKma7XDUV6w=w784-h1041-no?authuser=0)

(https://lh3.googleusercontent.com/pw/AL9nZEVj2n_jh86lw6F2YYyC-bptMydGyccJuekWa7uFt1VnWCRHFpjWxKb0WWOz1KOskmTj6mlXIaWAaNycPcOQXI6jxuuFhBe_WzeX2ENueTT0Ff9BKc-gojATPe3NCyF8JpK01fw_DjVu7znRvc2yZRQBMA=w784-h1041-no?authuser=0)

Next is the cam.  I've made several on previous engines and I've developed a reasonable technique for these simple cams.  I started with a piece of .75" drill rod and then turned down about 1" of the OD to .670" which is the diameter of the cam lobe.  Here I'm reaming the center to .250" after drilling it 15/64"

(https://lh3.googleusercontent.com/pw/AL9nZEWtXgtmYlpbfd7OhQ6WBmaxes7uty-H7Ou5LqKYq-3y3FByBXqfGDXFTj1OtuieubS4V6838qiY95T6UnxYiX4LcsP7LYS9cZ8cGD_L30WK1NsP_iD1TywhhvOy7UhtcHRqkOD19fw-i5QHWoC7Bqpwzw=w784-h1041-no?authuser=0)

That piece is then mounted in a 3J chuck on my small 6" rotary table.  The RT is first centered under the spindle and by a combination of rotating thru the specified 220 degree arc, and translating the mill table in y after offsetting the table by the radius of the non-lobe portion of the cam, plus the cutter radius, the cam is formed.  That's a very brief description of the process but the trick is just to think through the order of operations and in no time at all, you'll have a proper cam shape.

(https://lh3.googleusercontent.com/pw/AL9nZEWujbmIdWEmDdwmsUsS_R5B2CGgXmsDvQzN433InXvz0K8y0HeP63vetyHaHwBguePA1WtYF5Ffi9WaG6XWOkf21mmujXJhIDie0FdNQ-9cJ1l_tgqGVPTPaMxDqS0MYg8buGhpcXsR19y-9vfiZE7LOQ=w784-h1041-no?authuser=0)

And here's the cam after the work is done with the rotary table.  You can clearly see the cam shape.  I always make this piece long enough that I can cut another cam from this stock should something go wrong down the line.

(https://lh3.googleusercontent.com/pw/AL9nZEVfPScrpCXSPPdZjg-1BVxYiCtp37SUVKmZm6QfZtG-7XTwK4LMyfXKn13kTRHR4qvsks91YwiUMexumvxhpUhR8T5RTD7gc9y3W5Fn0lkexYmjh0UIL_HU6O_2_PPbqV4RteEMLy1_20hE0wK0-ROUJA=w784-h1041-no?authuser=0)

Then back to the lathe to part off a bit .175" thick that will be the actual cam.  I'm using my favorite 2mm carbide insert parting tool. 

(https://lh3.googleusercontent.com/pw/AL9nZEVU1ZfBpS6NQgjI35LhvSxCWVfTJzB7JDWOYdLZBh9sEoxmM93shdSqOwmaQqwasvRiNiTG07oBKBeapnXiAc191VvnPYFauoAyR5xj3ceUruqy4UCi66GKSPQjU3fFc_KwBbiZvnKpxFz4tIjVeTSGeA=w784-h1041-no?authuser=0)

And here's the finished cam laid on a drawing I generated for my own reference.  I that that drawing is at 4x scale, but you can see the resemblance!

(https://lh3.googleusercontent.com/pw/AL9nZEXuBQkiSj12xBVQwz9K35ZqPXVNPcBl8Xe1YIUQucRPZuF6ulIqVhdVkqMVtzKHeKPVpXgQQuZBdEYzWazjtfcW8UArhabqiz86GPOejtexdJNnoe5DdjGLaPTlZ29dpMrkwSBFhefXtx-PuQSx41ZYHg=w1215-h915-no?authuser=0)

And lastly the cam is secured to the cam gear by pressing it into place with a bit of Loctite 638. 

(https://lh3.googleusercontent.com/pw/AL9nZEXKcZHTH0Ia34AORKvSJGVVAyuyGtniKedtdJs7g2zj_oBdxdjKMc_4W_ouV5ZFa6z01kTywrcQgvyz6wrZjuIA8oPii8CId3Zh9xhdFAppYJaqSJV-P3QBPRbAOMdR9OsxOtdsCXHH_qrBofevzqQAmg=w1215-h915-no?authuser=0)

You'll note that I didn't exactly follow JEH's drawing on the cam and cam gear arrangement.  He uses a steel hub running on a steel shaft.  I think that this is actually a better arrangement as you have bearing bronze running on a steel shaft.  With just drop of oil occasionally this arrangement will outlast me for sure!!

And that's it for this bit of the build!  Coming up soon are even more small, fiddly bits!

Enjoy!

Mike




Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 24, 2022, 11:25:31 PM
I thought I'd document one more part of the build.  Since the cam and cam gear are lonely, they need a camshaft to keep them company!  Here goes!

I think you can make this part starting either with round stock or with square stock.  I had a scrap bit of 3/8" key stock that was just long enough so that's what i started with.

(https://lh3.googleusercontent.com/pw/AL9nZEXy1j8uyhgRhh10POfRjHofhNjBPc9ZsrA4jVhp7JZXAkIcF7su4trGA8BdJaASWoWPUiJXtO8IZ3z8lcE076v_RZ3067G_zEnFsw2Q_4Ta2QTDrX6Vi3V7lfS7BVQYcff2DPMBVgXt0nJuGTHywOWZkw=w784-h1041-no?authuser=0)

First step was to turn one end down to .250" OD by .748" length.  I didn't show the turning operation but it was just chucking it up in a square collet and turning it as shown.

(https://lh3.googleusercontent.com/pw/AL9nZEUX-ATuB2QU8t7XO3AgvNoM4nQB9cwFM2P2HPrSJvB3jzWTXIBpA3pc8E3iCv9xjL4cD5zkH7iHGT1m992vY9QAjito9qseDN1TG6bDau56FL4_iIDZnJU-sW3ESrE4WZTYWkWZm38pB_dNMFetLvnSQw=w784-h1041-no?authuser=0)

Then I changed to a 1/4" round collet and chucked up the part on the just-turned end and reduced the square end to .375" as per the drawing and as shown here.

(https://lh3.googleusercontent.com/pw/AL9nZEWGAxJna07KBVlVfV7QZicQmDNdS1-7IsrQ8cQ4fehRVbTfr04KvsOvMdD4MOKz50uSLzsxe286dh4DpBsBNnLMYMUp-Jw3qtsv0xksS31BroJOBOI3g9xYGVx01fBrhZuILaNaH6IA01XkY88BVsM-ng=w784-h1041-no?authuser=0)

Then over to the mill to drill the small 3/32" hole as per the drawing.  Locating the hole was done by finding the centerline in y and touching off with an edge finder in x and then locating using the DRO. 

(https://lh3.googleusercontent.com/pw/AL9nZEV4YK1ZyK-OdVD-xGOJ0QCDcgQ8Fxa6nVuMBk4eh1dt9mHR5IOA6_fSW_4k83oFhHWbUT1k_dzHTatR7qjzuHjTMnpUCghV3536HAsNZj29nhBJCRttliCSUj6nRDiLz1kWz50gpZ3ybnBJtnxpLYjd7Q=w784-h1041-no?authuser=0)

Then the part was repositioned in the mill vise as shown and the center of the square end was milled out using a 1/8" 2 flute end mill.  The slot was milled from the centerline and moving out equally in y.  The slot dimension was confirmed using a pin gauge.

(https://lh3.googleusercontent.com/pw/AL9nZEXlTHanzWDBkFLBDgR-bAaAC39Y9OJyx_H6glqZsw1jez2Kn7osx1Nf9Usyw7aP5Nn8i1Puhiil0iw72EUKG0jBuIhba9kdLCjMQi9hYyczZlJB2lTwLPzJMACMIKLoBnJ6vqavTqA9B70eA4aX4-OQtw=w784-h1041-no?authuser=0)

And here's the part on the drawing after it was completed.  I very lightly rounded the edges on the belt sander just freehand as that small radius isn't important except to prevent yourself from getting cut up during assembly!

(https://lh3.googleusercontent.com/pw/AL9nZEUOP2WpoUXyslCHaSBW-0yGtHOocDa_KYFEs0E5Mx_ldupj6HuMX_MENFmL7CNvtHNR4Ig3CkvYfwRNqxSH0eKHRw2LgRe6pyzTQtVktoD6Tyo-qoplab3N5xvJ8xD4OToDN2B171aky5mvQmE9urg4QQ=w784-h1041-no?authuser=0)

And lastly, checking the fit of the cam gear assembly on the camshaft when assembled on the engine frame.  By some miracle it all fit!!

(https://lh3.googleusercontent.com/pw/AL9nZEW_AcwUmC0xf-VxXFRYO44agOFbvgG8StfCn8Lxf7bR8NJwQndQ83i2eURFqrAeIwVjfEMMdwAvod6KKVJMNhK_X0LGHd3pusVmT4y4mnc6TnH_3KQWXyMr8k_4uYbJj2gW3sBMgvWCcbtQcvAo2r8niw=w784-h1041-no?authuser=0)

That's it for today.

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Admiral_dk on October 25, 2022, 11:33:50 AM
It was not until the last picture, before I realized why it has the shape it has  :headscratch:

But now I see that it is a stationary axle - with a 'Holder for the Miss Part' - so to speak ....

I do like your use of a good bearing material as the centre off the Cam+Gear  :ThumbsUp:

Per
Title: Re: Farm Boy #876 - Mike's Build
Post by: Don1966 on October 26, 2022, 12:15:42 AM
Awesome work   :Love:


 :cheers:
Don
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on October 27, 2022, 01:02:21 AM
Gents, as always, thanks for watching this build and for your comments. 

Next up are the flywheels.  I like the look of cast iron so I ordered a couple of 6" flywheels from Martin Model from near Portland, Oregon.   The flywheels were pretty good as received, but perhaps a bit rougher than some of the others that I'd purchased from him, but still are perfectly usable.  I'll show the work only on one of the castings as there are only minor differences between the governor and non-governor side flywheels. 

(https://lh3.googleusercontent.com/pw/AL9nZEVDlQSRppoWDOVp76fMjTQBKyBt3qWGTcVwrDmH0tVrXxfe4PF61Q2DOetyWCYW4nXcJfIYxUzrC6yplEtO-PGrAkO1Tton3XljN-gTovkwLO3EFUdYzsGjvSqHV_gWSOHENTRvghk7mPmCjSkDLXILRw=w1215-h915-no?authuser=0)

And a closeup of a small area of the as-received casting.

(https://lh3.googleusercontent.com/pw/AL9nZEUDnIIjNMeP5PqzzCCQ-tUekUIi0KoFijOZPyOoAwLBhLOSEboVcwrFbJfkgabw-V4EDVcOVW9NPImWQd1EbWB6W-noctwVwM3fnIcmS1vtbs_Vfse4iLTD-7OKMa1oGhNS_gPsxJrPVQw2ZtuDbfdDSA=w1215-h915-no?authuser=0)

Of course first comes the fettling to remove most of the flash and to smooth out, at least a bit, some of the non-machinable areas.  Here's a pix of one of the flywheels after a considerable amount of time had been spent on smoothing things out.  You can see my weapons of choice:  a Foredom hand piece driven by a Harbor Freight motor, coarse and fine emery cloth strips, a flat file and small and larger round files.  I'm never quite sure when to stop on this process.  I'm sure I could have done more, but at some point, I just get tired of it!!  I'm counting on fill primer and paint!!  ;)

(https://lh3.googleusercontent.com/pw/AL9nZEXvO41LFZFIlw8eoyfPwAdnYYv18qeesqY06FYo_M49QX64yfcV1fy8rmvoIXkNxgJw-MUNP4m8KTAM8Cu8xKDtmkdeh-E43uTUq_bQrTMBA379n01-xJCIM4j75cdu77KOjR_G1LRrQ_5ZRpQtPJ4f-w=w784-h1041-no?authuser=0)

My process for these flywheels was to start in the 4J chuck, gripping on a bit less than 1/2 the rim thickness.  I used a DTI, not really to measure, but just looking at the tip to get the raw casting to run as true as possible both in z and x axis on the lathe.  I always struggle to know when it's running 'good enough' but at some point it seems like no further improvement is possible in how it runs.  The black marker on the rim is a really low area and I wanted to watch to see how that came out.  You'll note that I was looking at the interior surface of the rim to get that surface running as true as possible as the exterior surfaces of the flywheel will be machined true.

(https://lh3.googleusercontent.com/pw/AL9nZEUACsypwhWucXWbtDDVSiKzU-Fd79DYqjhFyBY0LTTB3ihOwSlkJ6fCYBG6LUrLTbvU9F896C1IxzGBzwxKdQVFOju7cVAmdU0ou_qmo0eucmGU5DCFh8SxOGN609wF00YoANhlkpLqVDUMmG19HN1O2A=w784-h1041-no?authuser=0)

The first cuts I took were on the rim edge and the center of the flywheel.  This just helped me look at the wheel as it was running and it removed some of the really distracting motion.

(https://lh3.googleusercontent.com/pw/AL9nZEWQ2oVrHa7lnR5qSBNet_0tfwH2qx51mHqANRALiUJdGBUEVTUsq6afBkmlPn2ef00zucq7bvvvEp0olCDB3hHb0ncWB5GWoTzfElZyLHOeYpIKlmCbJftGuocXxE7j6bpz1R-nC5iGeXoXQim_9AnTdA=w784-h1041-no?authuser=0)

Then I started taking cuts on the rim OD getting as close to the chuck jaws as was safe.  As you can see, I had to remove about .125" to get the OD true, but I still end up at almost exactly 6" but just barely.

(https://lh3.googleusercontent.com/pw/AL9nZEW5Y6vdiO7YSubv5t5JZn7sJ8S3pHyYpDtImutzs84QN09bs26y4W1HWNp6bJ7w10et3AivcQ6SE_cRfz4KHuYr-FLMtPhk7mevg57YpsxCHzGk0vA0itxO0kpPjmTXkppvsyRoYQB7XrIRQAUKYXNPdA=w784-h1041-no?authuser=0)

Then with a carbide insert boring bar, I cleaned up the portion of the rim that was machinable.

(https://lh3.googleusercontent.com/pw/AL9nZEXxyGdNhxE5bYFw7FGyRSWrYrEHb6c7gpslmU1dJhmtSsPKgneV2UkATfOWd_YtG4dhV2C7P5MSvon8k24z64A_npYGbquGwex4-RlmNwgs5s6Lym4Ue6QM0_OYKAQ74uNl9A3BNZFnkcUtlK-Qkdbocg=w784-h1041-no?authuser=0)

Then the hub was machined to its required height.  Note that each side of each flywheel has a slightly different OD and height so close attention to the drawing is needed for each flywheel.

(https://lh3.googleusercontent.com/pw/AL9nZEXrabCJaGCtCg9FYXnfG-SsjdEfUcOMmYLwxMBQ6xIKI3zHMbYuRx2KG9vSI3ZR-SFVYPE7hO1lza-bjHrG6Z6L3bpbFvSs5YCf-XYHtjaD4jILTXngcXZQR7MK1XwXsBD5pLglZ-GJb_hcw4tTWuA2hQ=w784-h1041-no?authuser=0)

Next I turned the hub to the spec'd OD and cleaned and very carefully blended the hub OD to the spokes.  I used a 3mm carbide round profile tool as it creates a nice radius between the hub and the spokes.

(https://lh3.googleusercontent.com/pw/AL9nZEWkDgW3vObcCpek1PDwGo9N4Q-iOhqYNWjYNVoiQEAtJYfhc_4FXsl98-s5IgYaJXrApattcsbKln67ImM-_yWOXyitwOHSCIzbh-FQEHhBDvO8Ic5Y1zGweP1lP9vnhrPbWKt9j8RbMjTPI08DqT2bjQ=w784-h1041-no?authuser=0)

Once I had the first side done on each flywheel, I installed my 3J chuck and reverse the jaws.  Then i could easily mount each flywheel since I had a true OD and one side of the rim was flat.

(https://lh3.googleusercontent.com/pw/AL9nZEX3eSaAaw_pkoi4Qxfokk036Q8lQiV2LaVeTPQRHMhAKx916-1460FtJW_ids-3PwCYVkvb1hg1qfge3vTDZwN3FkEBu0_nM_B16OPbnh-FswQFMSjDdW_6-kp4-WCAEvEiNRqIGhrWyBy-5lDByQo2bw=w784-h1041-no?authuser=0)

Then it was a matter of repeating the machining as per the initial side but again paying attention to the hub OD and height.  In this pix, I've finished machining the 2nd side and have drilled and am now reaming .375" thru the center.  And of course i checked for a good fit with the crankshaft. 

(https://lh3.googleusercontent.com/pw/AL9nZEVLzMlbOmIO1omX8SAsFmGLKH6PU3A8GYrDMtdkYX6gscRrA5yPUyoMsuV6lvLrZZ8VaGWgPFMmwg21oJUNUjTQJlI3uEyhaMzbqzl4vkKwxkAVCYAS-tBwts8knrLTk7vSBvLRHEhDnVg5hv8bt8uExw=w784-h1041-no?authuser=0)

One thing that I always do is to Loctite in a stub shaft as shown here.  I failed to get any pix of the next operations, but I chuck that stub shaft up in a collet and secure the other end with a live center in the tailstock.  Then I take very slight cuts on the sides and OD of the rim to assure it runs perfectly true with respect to the hub and shaft thru it.  I find that this process results in true running flywheels. 

(https://lh3.googleusercontent.com/pw/AL9nZEU3qsjDP3_qgxyxwwZ6g9DboArgMdW6K44BFjgzSL_C_48CLXytQtru1J4DaF1B4bzaUUGm9GE-S6OlPiPVe5WBKQxLEyrWnMlsPmx7aV6xdZ3PnsOLy8hvAsjIcOcN8lh_Tk5lZzZHm2wlPd6RNdbOwQ=w784-h1041-no?authuser=0)

I chose not to follow JEH's drawings with respect to the flywheel securing method.  I like to use a key with key ways in the flywheel hub and the crankshaft.  Here I'm drilling and tapping an 8-32 hole.  The easiest way I've found to do this is to hold the flywheel using the stub shaft in a collet block and inclined at 5 degrees.  Then I use a long center drill, an aircraft drill and a 8-32 pulley tap to make the hole.  I found the centerline in y and then visually found the edge of the hub in x and positioned the hole accordingly.

(https://lh3.googleusercontent.com/pw/AL9nZEVXJaBEoK9gwjuCi949wwONICCmHCjFJkb70UjSjY6daIWzkMW_TND6KwblGCM4PKWzEK1DZ7tTVSOvpC5CinlorwTb4k2jF3mFVuixmbOECDk-ZxNmRTB7ekvNlB7cUOKmKc5lV2hy-D8MdOa67hrFYg=w784-h1041-no?authuser=0)

Then it's over to the arbor press to broach a 1/8" key way thru each of the flywheel hubs.  Here's a wider view.

(https://lh3.googleusercontent.com/pw/AL9nZEUMjU2AgeO3QwYSXn-AxqET23ZubdEK75kj8qmy4j1MrUedWio8hBZsgAwv2hbp8UwwnoQF8vCoOYvnFUzxXdQJVTrcTlyBWuqkOJQGB2ZHVcc_5AbnnE5CAdkEL9n5dXBj_5iczD8NjGdE8A59rRwYmg=w784-h1041-no?authuser=0)

And here's a closeup of the broaching process.  That's the first pass thru.  You have to make 2 passes, the 2nd pass with a shim inserted behind the broach.  I use a liberal amount of cutting oil on the broach and just visually aligned the broach with the set screw hole.

(https://lh3.googleusercontent.com/pw/AL9nZEXnhViJF8Qshxf5y2AoUdMHakCLoEFP8PlJepOfsyG2XfN8nfP1HtEdUFimEpyZOzDJ3RQOwQYl_j4nz-ZddWLoiOKDSgEieBwBjam7KI47K_uUReeJRgjwzlU4mHAyjt-LERZ8YRjASXBk7Lxw5vzdeQ=w784-h1041-no?authuser=0)

Then it was back to the milling machine with the rotary table installed.  The RT was centered under the spindle and I made a small alignment pin that fit the RT center hole and the flywheel hub hole.  Then I put some AL packing under the spokes and secured the flywheel to the table with some t-nuts, studs and nuts.  That's a 1/4" carbide ball end mill in use.  Note that the drawing calls for that slot to be aligned with the key way and across a 60 degree arc.  It's actually a fairly easy operation.  I made sure the keyway was aligned with the y axis, then offset in y and rotated the RT 30 degrees each side of that initial point.   That ball end mill cut the cast iron like butter! 

(https://lh3.googleusercontent.com/pw/AL9nZEXE90lXvrv4m_zDs8cZE-Kjgenq1ZXoUz8UM3MrE8fFecnCDKp3oDqf42pZQ0usgsKAX_OzFBJHCzWnLn9Qkyipy0ettS5Q4DcnhQgGxCczf_pGVVzN-8Kckrku1J_H23VwSHnP9FvGgxD5m-1eaTLztw=w784-h1041-no?authuser=0)

And here are the 2 flywheels completed!  Note the differences in the hubs.

(https://lh3.googleusercontent.com/pw/AL9nZEWJeOYssGCLLZoWU-xgOS3zDvYImv3dtIWkXyiCdKQwkvG6bOEWP9fOdEpYTDLKtP2eYVehegTUmYQsP_r-6e2RKEMvlDAcSbkLSl9MGgyG1ujRyRZ-2onWl1q__wqv4_OulG-tHqqJs-BJ2RMaaxZcLA=w1215-h915-no?authuser=0)

And lastly, here I'm checking the fit of the crankshaft, key and set screw.  Everything fit very securely!  It must be another small miracle in the machining world!!

(https://lh3.googleusercontent.com/pw/AL9nZEUI61WWiL4qqnS0yD-lSDbjVGglgXRByPDZxg0KLrf-Ghh_V-clh6EwzUPgCpBuN5W-3tvIpi6HVKAMwgy8iwMm2Bu_-EEbCUsWURfuJ5z3iLRry3B3wmxw7eCs73rcSx-l5X_wASqx5xmjrphMw5An5Q=w784-h1041-no?authuser=0)

And that's it for today's update.  Now it's down to the carburetor and hit and miss mechanism and related valve training components.

Enjoy!

Mike





Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on November 08, 2022, 08:13:09 PM
Sorry for the delay in further updates on this build, but we had our first short bit of travel for the first time in 3 years!   Very enjoyable!

Now on to the next part. 

I tend to add a method of starting engines using a drill motor and I shamelessly copied one of Brian Rupnow's designs for what I use. 

Here I've started with a bit of 1 3/8" round stock and turned 1" of it down to 1.25" and about 3/4" of it down to 1" for a handling stub.

(https://lh3.googleusercontent.com/pw/AL9nZEUC0exzgNmjtwMGWX3vdhWQEfNMWtEMVNRr39cRgv9vyHybZiYGkv3d0ZQZZ-4dswfREdxpcfNsXU3YQmiV_4qWmaXPpParUj0IW3Ce8BTmvKc97xHSj62OztN92e0t3E2pHennk6inhumdtxoT2Lt15A=w784-h1041-no?authuser=0)

Then I drilled thru and reamed to .376" so it would be an easy slip fit over the end of the crankshaft.

(https://lh3.googleusercontent.com/pw/AL9nZEV3Pw3I9CDehL_W3p75jKdcd6lPBKd6OqGSOPprIKdzWl6wD2DLjqHCkyXnquIWJZWQVoH_INITm4qMlWpd6zForiomhKABXt3L6b_wsu4M9fe2xswsYPhbEf_WfgHrPsnfE3smTa3ipFWwzJ6n6r44sQ=w784-h1041-no?authuser=0)

Next I reamed a recess in the end of the part .75" ID by .45" deep using a small insert boring bar. 

(https://lh3.googleusercontent.com/pw/AL9nZEUfUn0L5PBqNhIkAL9AkTWZ9LmeJii22wFP0EBi5EnKVOlDLBUKXi15MQfdKARn6F0UCzN_tfbt0s9a9IW9ki0cG6dJ9HF5WzADMjUG_Uoqg9IQgaYEYnwQTRkCTeMjssSN2c1zZCPsNxM5WXnTuKSDAg=w784-h1041-no?authuser=0)

Then over to the mill with the part held by the stub in a collet block to drill 2 holes for the drive pins and to drill/tap an 8-32 hole for the set screw to secure the starter drive hub on the crankshaft.  The collet block allows an easy method to orient the drive pin holes and the set screw hole.

(https://lh3.googleusercontent.com/pw/AL9nZEUhFZp2N-uKFOANdX15rNrYaEkZQ81g5x90B7TiPkNOMHGgwm2Pry34H7XcOsI_XCqskX9XSBh52VfcZP-FgBe3r91Fd_MSEH14tjLuJPZjuDg6r3Kp-wcYgAiS6m12h3WeUmASrXh74pMJxdQtf7U8xQ=w784-h1041-no?authuser=0)

And here's the finished part on the drawing.  I didn't take any pix of driving in the pins nor broaching the key way for the key, but I've shown similar operations previously. 

(https://lh3.googleusercontent.com/pw/AL9nZEW9v87ndmR1uMIP5XC6nqaZ3izSfDY0dLr2ZCqwzDzKiWP7kJZpX0_nbiphEQnxVK1CMclT9tBxbRxEYCK0Ju-9AT8zNyxbNE2X99RlMLGCV_M67HHC7rdGIGwrj0J3dZZJ3p3yOEvHvpLJiyBg983YOg=w784-h1041-no?authuser=0)

And here's the final pix of the hub mounted on the crankshaft with a pix of the starter spud next to it.  I made the starter spud several engines ago and it works well so I've not changed it.  I use a drill motor to drive it and I can disengage it easily as the engine starts.

(https://lh3.googleusercontent.com/pw/AL9nZEW97ibBnExOM2KpncuoRGnT8By4-qrpacsvyfYUnx9LPHt_xh_DmKlRRUuGN9C1fUO2QZFUwv8HgT6q5pOpdKUTheyyRK6d6uBX2EORnOJs9hzkYNZR508mfYS3EqTp1KE47LYxXSQtLYbeFaZDAfhHLg=w784-h1041-no?authuser=0)

And that's it for this simple part.

Enjoy!

Mike

Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on November 08, 2022, 08:50:31 PM
I'll quickly document the build of one more part today since the last part was pretty straightforward. 

This is one of the smaller bits and I'm not sure the way I did it is/was the best way, but it worked.

This part is the exhaust valve rocker arm and I'm starting with a piece of .5" brass rectangular bar stock saw cut to just slightly more than the finished length of the part.

(https://lh3.googleusercontent.com/pw/AL9nZEXbR8LhvjXpq1394VtLB6nTD4ZucCumdtKcIV9PvaCBJWbQxvCS6l5aJB4RoJ-r5al53H_VrzUq-kodYZ6xEHIQuOWlraU1U0t-cDT9gHE764IVPgHunW3R_6ytgaJRJAr9qD4Mb0LcVE-FndQGCdWoXQ=w784-h1041-no?authuser=0)

The first operation was to trim the stock to the OAL of the rocker arm using the mill. 

(https://lh3.googleusercontent.com/pw/AL9nZEV513XoDUoYyCZiPUC2MPWNM0qwoQ8_-1nn_OStz726aghSrv6ZTVdj3gnh46uI5EgjVL-FypebGiDQaq_9lpRM6iNkGBYRmjco-DksilwKnJ6VPKuBdVMIuoJPyBXcaIRwRn4z4xPjLqDMXD20qO54Xg=w784-h1041-no?authuser=0)

Then I blued up one side of the brass stock and drilled and reamed the 3 holes required, 2 were 3/32" and one was 1/8".  I also lightly scribed a couple of reference lines using the mill, mostly just for reference for subsequent operations.

(https://lh3.googleusercontent.com/pw/AL9nZEUXGC_nI9gmewzH4PZApiekm-mrLNzGLOk9QF4V5bQ0SCviChvP0NFtzbFrdzsP2oMkCuankPBecUBWTrkuQVrKUzVyx7WPNxqXEqiOdwJlvoPnhp3WjPB6FMb-fLnT2Dqbm6l6M78oq3kDd7sFpYpsOw=w784-h1041-no?authuser=0)

Next I marked the end radii required using a 3/16" end mill by just barely scratching the surface using the end mill.  These are reference marks only, no functionality implied.

(https://lh3.googleusercontent.com/pw/AL9nZEUNODmC0lqm6c0p94lIVhKV3dXaZgA1CT7ayiWnQFKBYnoJ6DjIsk20h4J-C03t0HIKEqbCUYC47K4miPVnEgmwS9tNiJNGZQM_9Ilqvn40F8R-iKpeNA4xNQZJtJQkr02XAIopfqVBSWykYHrrxG-RtA=w784-h1041-no?authuser=0)

Here's the stock laid on the drawing.  You can see why I blued and marked up the stock.  I was then able to scribe the angled surfaces for reference and eventually I'll be able to create the rounded ends using these marks for reference.

(https://lh3.googleusercontent.com/pw/AL9nZEXB5u9o7QMr2JyXUwtiMQ6X5DD4BhGBvSb4aAKn9HOFJDHLoJZKocQtr0kgkZ1hQo_TNsK94aX3ifXICsYvMygdXxsT2dy5yl-aCX5k4BhWvAwZ-FyOykRBxWWDv3rTWf0cCjMFj1ct6eOk6NahlfSw1A=w1306-h984-no?authuser=0)

Then back to the mill with the stock set on an angle block.  Here I'm starting to mill away the first angled surface using a 1/2" 4 flute end mill.

(https://lh3.googleusercontent.com/pw/AL9nZEWwvk0QFWo56eoysVfZlhW6r2QfCwXArRZTqZxb61aIXLt0Yta8NppWn9Hy6LtgWZFQIzgdwBrQg4mZ7AgSn516iXpAolVUDHGMYmxiK3K529dlz47Jt8sTXoiRB7wG8HVkOzHh9cG_dMrS2ZL13wzTHg=w784-h1041-no?authuser=0)

And the stock back on the drawing showing the progress so far. 

(https://lh3.googleusercontent.com/pw/AL9nZEUON7DkFpXMTbjRDhulBaLF_GmYOyPekm2YaA-bmwsbdUG3u9kjXtYDu6Yi7W-kMIFsZpqIHZyMEmV-HFKrH6yfEfD6QKazSRi6K8R2evNKJy6jhvi1K-i5Id_YrpdroIExgnQssEERmcjEMJxBwqGlUw=w784-h1041-no?authuser=0)

Back to the mill again.  I'm now milling the 1/8" slot in one of the ends of the rocker arm.  Pretty straightforward after finding the center line of the stock in y and finding the right edge of the stock for x positioning. 

(https://lh3.googleusercontent.com/pw/AL9nZEU1Lx9tG0a2ZmMGyo2ThxjrCyJdHO9FcI4ZOoMKSDU1roR9Npm-ROEUkKVymBJtWcVcc2JX3N_v-cYm7udxTiEl7gezexiiWPCiXGYWUkzc01sHLLxWxG5dkhDjpQkux-gNlRzwLXowFZj00ReuCA8X4g=w784-h1041-no?authuser=0)

And here I'm milling away the material on the sides of the stock to form the shape.  Fairly straight forward using the DRO referenced to the y center line. 

(https://lh3.googleusercontent.com/pw/AL9nZEX03rLf721SlSNnI-pvXaxQI8FJCo0TMUNhtxtvIheBxxukExiMDbIcLHDyg7PmM9FFvbFtwuSsCS2UxvagqwVWg3I9jwZIpaG0clBRtFpuMG-KCXNmWcKeFTFSRsLF_Dx-EWy1pOc5YKQGh04ChiswxA=w784-h1041-no?authuser=0)

I didn't show the operation, but I sawed the part off the stock using a slitting saw.  I rounded the ends and center using the belt sander and polished it just a bit using a small Scotch Brite wheel. 

Here's the part as viewed from the side.

(https://lh3.googleusercontent.com/pw/AL9nZEWmeg1bFWNfnbnRIJClyKnYv8hpVKsk4vCltLLYA4Rn-MHDTaEBKyKDxoxbd1fZFybLNAeASPAF2ui3u5oxAseFx7fkfdUSI7BWfjw-Hi0RheIOFXaMphxrw_VsVkaWoIBA_h4bku5J8FU4otO7goB_Mg=w784-h1041-no?authuser=0)

And as viewed from the top.

(https://lh3.googleusercontent.com/pw/AL9nZEXASwY2r6iS_lAE-CemRiQw0fPV2h4-3zbTP4jCb2HHA0No5mRWJl3DyQTJvQEHwSvbVVZSVdUYoftzXN8wHxTXUjYnQ2XQrXxkTVuN18oPLijuEpjlJDAlWPsslYkRXX7UeMX1heL_S1Fij-eyV150-w=w784-h1041-no?authuser=0)

I think the part came out pretty well using the process I described above.  I'm sure that there are other ways to do this part, but this turned out to be fairly easy.

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Admiral_dk on November 09, 2022, 11:00:30 AM
Great description and result  :ThumbsUp:

Per
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on November 21, 2022, 01:09:06 AM
Next parts up are two really fiddly bits, the push rod guide and rub plate, qty 2 required of each.  On the push rod guide, I thought long and hard about the order of operations as some of the sections through the part get really thin and I was afraid of breaking the part during machining.  Here's what I ended up doing.

I started with a small piece of rectangular brass stock, .5" x 1". 

(https://lh3.googleusercontent.com/pw/AL9nZEWwW12F0Vgu4MgRztlutV2BOKaS4zGod-vprqgClMTkW1WnV5CO28oTqglBCWm71aUvehVngSnBcmfwWke7Ww_DH8h9usvCFiylH5ZbQgy3vKnnEFjxqYp0tuPwh79V7D7K3NmfweKYt3PpqCYxGX01nQ=w784-h1041-no?authuser=0)

Then after inserting the brass into the mill vise, I milled the stock to the required external dimensions and milled the material out of the middle of the part. 

(https://lh3.googleusercontent.com/pw/AL9nZEXo5CQaVftOagyG4GZvxy-B9b1z1j-F6RUoz22y016ZMcKbmCTIVmbNJHLIgW1kWmQCstO1KIhrDe_Kk3PwhDUvr3XNaHsxvqFedXWuei5U759x-iO1sSf9zALhwx70Wxy4Me_CzalH4LbNeC57yYD0GA=w784-h1041-no?authuser=0)

I parted the piece off with a slitting saw and here's what I ended up with so far:

(https://lh3.googleusercontent.com/pw/AL9nZEV7TDJJpZlOLrtYFrUZnKHfFgqGjEcLKHt7VYqFspicGftXo-_hv1AFLkL7bUViUKc8P2DdKy90xkxBUkixkMRC9hLuhnN-Gsvl9CXxZHjDZo2CzPf7N4-ZSeTgcUuX7vxwj_vViycwbt7FfKFdOm8elQ=w784-h1041-no?authuser=0)

Then back into the mill vise and after locating the edges drilled the 2 required holes into the part.

(https://lh3.googleusercontent.com/pw/AL9nZEUeY_4mDyI9Ksgbe9_pmsX4Jc-jJfZOKS86Zw1QPvE2rpRJW8WTHnpDN4zfiy9wh0VyOZ1oFewCJHAOWM7b7QI_fsYTtz1-LYrutUECflQjlKZUx-2Zle0bL91Q303yhDXeDxwzUt5PX4mShTbLfZIifw=w784-h1041-no?authuser=0)

Then without moving the part, I milled the two recesses into each side of the part as shown here.  End mill was a 1/8" 4 flute that I just barely stepped over to achieved the spec'd width.

(https://lh3.googleusercontent.com/pw/AL9nZEUfv9jVwRIUKIsq-4_D2cIvSrAIoUVfdEUP95dkR50IBXR2e8K57W358XhfBZ-yr1oXEc4LSW2ix-kU_7lwoDDcNxFqrgGvr7bOf0xaNUrZ1Giwv6JsRJlheLUrwQeFLiDFGRNmniG3zhXtG5cdwunVyg=w784-h1041-no?authuser=0)

And here's what the part looks like with the operations completed so far.

(https://lh3.googleusercontent.com/pw/AL9nZEVUaJB3dT4eCtWq5yXUIo3KqQ_54jCKtRlLavUGl8-uTUg02ht3Cyx3CMGMojI4ZRpow2kZoy0CO_mZkUkeGFRS9z7tBQ_wR4g6G35uHMcAAZ95lA1H_uTUDdnUsPw-go-yPl-d1smrZOEFkdplm0CprQ=w784-h1041-no?authuser=0)

Back to the mill vise one more time with the part tilted using an angle block and then milling the side features.

(https://lh3.googleusercontent.com/pw/AL9nZEWWdvp8_D4ZtKajC_ZR1iHGLrx8CXM4oBaxbfKcKD0EJrIY6MFoWTagTIeDqWzCtWMNorUIpgElPWEUcSeZPuKxiVbcWGu0W4_JDXfDzFA92BVtd9Rr6Vt1XeJizfcpOKVuNR0k38NLV2SsfgnsejxXnQ=w784-h1041-no?authuser=0)

And after that operation, you end up with this.

(https://lh3.googleusercontent.com/pw/AL9nZEXLLQz6LEjusVCTCNjTXCQ_lygAq37v2A0tdHRhbAmvMzDa5UeGZAEYieeQB18_uMCi0xqPHQrgLxltxVxj_YtpukmmKoYf73cuR-EAnNOfOgk-96JFO9ZwyhamvyQe8pWSyoLLPzxcciB9ddYs4PfLiA=w1351-h1018-no?authuser=0)

I didn't show milling the top of the part flat, but I indeed did so.  Then I repeated everything again and ended up with two parts.  For comparison the 2 completed push rod guides are shown near a 20p British coin.

(https://lh3.googleusercontent.com/pw/AL9nZEWXQ2u5cpOpiRd33aRScdmmjB2qqdzB4X5V1a8h1hNbHlfDNLPwL7Wvghick6My-N8WhjPqaomUN_WePTcTvltISPpvzYvLdWQxW2FFyzY9KEa8z1CGpwt06PdfTFYxXliYpsGJYQJTgNLvl4pslACREQ=w784-h1041-no?authuser=0)

The rub plates actually caused me a LOT of grief trying to get them done.  I had a strip of .025" brass of exactly the correct width so I thought I'd simply glue them to a bit of AL scrap and drill and mill them to length.  But after numerous attempts with different adhesives and technique, that approach utterly failed.  The milling operation broke the glue bond each and every time.  I don't know why as I've seen others use this same technique, apparently successfully, but alas it didn't work for me.   Suggestions on how to make something small stick to a fixture are most welcome!

So I took a much more direct approach.

I started with the same piece of .5" x 1" brass stock and milled the top of it to the required external dimensions and then drilled the 2 required holes.  This was of course easy as the stock was completely secure and stable.

(https://lh3.googleusercontent.com/pw/AL9nZEVQcC-e7FK5884Z-Du-JGt0FFpo3FCZ56J5ARaD_wAVFmN7p6OlVZ9ewdIZbD8f-yp449HRiqai6iTlPRQ0qgV3HnpJ4vp1aG9mmuKVFqAg8DPle5IWKplfouaW-rY2Phdcd07CU7PAYNZY0CP-KUTJfQ=w784-h1041-no?authuser=0)

Then I simply sliced off 2 pieces using a .030" slitting saw.  I find that I can perform quite accurate cuts with this setup.

(https://lh3.googleusercontent.com/pw/AL9nZEWTc5Nq04xE8C1Po5YvAs1TXHBLgC3U07hiOXia_mwvxb3XIYr3At7qoqnPUcNm9-VFZoGrjwRJNHkMIZOXz4ir69keePZjfhgXUgf7eFiGQnRPR8UrWKBt7yp99ILE2zjx9W-uiyRGZeAG-OMt2RpIFg=w784-h1041-no?authuser=0)

And here are the two rub plates laid on the drawing with the 20p coin for comparison.

(https://lh3.googleusercontent.com/pw/AL9nZEU8qlNcWo95Jer2yVm1QmMQqvh5Siu9N2YiiMBmY5Nkprt64NA-e2GyuQTaiWmIOpdsPp0rKc2kV8iElF8uY8dC4T2fcyvS-PxcvpU_f4KTcy5TPP1JytCwFjlM66-bz0gsTRnxllf8mgPYEu8qiSlIng=w784-h1041-no?authuser=0)

And that's those 2 parts done! 

I'm going to post one more part right after this as the next bit is integral to this assembly.

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on November 21, 2022, 01:29:55 AM
I'll document how I did one more part of this assembly, the 'Primary Exhaust Valve Push Rod'.  I found this to be fairly straightforward and easy'ish most because it's slightly larger and easier to hold.

I started with a piece of tool steel I had on hand.  I'm not entirely sure what the alloy is, but I think it's A2.  It actually machines quite well.

(https://lh3.googleusercontent.com/pw/AL9nZEXH3qaGi12BoMXMENZ2A60TUKwgj6E1nYwWs-b4puKr1SODlzlUBdEBLtHEeb0Gkk9_zp0nPXMcvYIq0pSpoP4mlp9bVUpz8SSeHIuerHHupI3jPMFZ_zqQU01nKhmTTPRJDVyshueZadNRiSlMpvclwA=w784-h1041-no?authuser=0)

After sawing it to rough length, I machined it to the finished length, thickness and width and then machined the reduced thickness on one end of it.

(https://lh3.googleusercontent.com/pw/AL9nZEVtgEb1lWwtv48sgYBh4ccUIwjvUhgksZbMeS0imSLgj8hA60bvwmLXZdZUs4XCK_w0bi22HWUcSfv9AsBmW0psjJ7teV7sCarTekEGSAEIgCx-FuDPebQeZ9j7y2brXIrEPi4tGM3Y4JIUiEKUM4L8lg=w784-h1041-no?authuser=0)

Then there are 2 holes that need to be drilled and tapped 2-56.  I used a spiral point plug tap and rotated the tap by hand while held in the drill chuck with the mill kicked into neutral.  If this would have been a couple of blind holes, I'd have used a tap follower and a very small tap handle to rotate the tap as that gives a much better feel of what's going on. 

(https://lh3.googleusercontent.com/pw/AL9nZEW_b6o9LOw8F3RljrPWQ8gwBKMUywnYScu9mxEtc7GeafDG2-EEjC5LKk3QfaNgXuf3a1p659ULjQTZ9VSqZJivfhsjSf-7uYcLtyyocw67Ty5od4nXwEDJ7mqkGD9GrfJj411-0D1A37MJfhViA5MoZg=w784-h1041-no?authuser=0)

Then I stood the part on end and made sure it was vertical and then drilled 1/8" hole in the end as per the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEW2deUQ_1V3xUk7irQCUPUxIBSAlD2yNbxhElqJoO1XJfdRm3njtW6NSWg9Vu43DZ2fRmXvVyzpgfNf8rJlG10VHt_r1mOKSj6S_FJb0XkUSl5mohSZ3rAOo2t7PgeZG8E1n9unbFhfx8gUx6G5BtX3yA=w784-h1041-no?authuser=0)

And here's the completed part on the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEULocvb9ZBhR_6YI_Jh-se18_7vJ75NvTMQjpDylV0pMnYY3APtcPaLndmfI18cnsrG4cJL6SGp1jJ9hKy2Z18dH4tCQRZqVYSPQyuHdkGOdM_ua5Ld4Twwa7CmMhrcXbXsUTFdtCj_YrxPJEX0A4UDdQ=w784-h1041-no?authuser=0)

This valve push rod requires a 'Push Rod Stop'.  I started with another small bit of tool steel and milled the external dimensions and the slot in the center as shown here.

(https://lh3.googleusercontent.com/pw/AL9nZEU_9tkDF_5dMxT5y4TxNUTaVyXb9clb7FPVFpZyLs3OJ_mkGAfFDACHrphG9Y8Du4B7NeGvKxOTfC9rSMFA42_KLiYKGlAbs-ayaMFmNYF_lF8Nk4Sgyqv8K4m4-amJvMko73jPGTccYhu_etMuIVaMXQ=w784-h1041-no?authuser=0)

Then I cut the part from the stock stub using the slitting saw.  I think I ran the spindle at about 500 rpm and slowly hand fed the saw through the work.  I used my mql system to blow the chips clear and to keep the cut lubricated. 

(https://lh3.googleusercontent.com/pw/AL9nZEUaIaLsoPvpqrqn-wAA2MI6E2N0wAZoraisepeKYBQA0UdSD5pNtfnzJdZgWeGRpHRZjjVtADdMgpVG1ZaOfTGqKpsjhLd6zS6_L4D6tYtQdcVUWOdkJD0EelWWYCFI0vd7FwEaS2gGbkEEVvh0FqgfIw=w784-h1041-no?authuser=0)

And here's the part on the drawing.
(https://lh3.googleusercontent.com/pw/AL9nZEU9NbPRTA8o5EnLijsCPpVZzWp7h86KqJvvn38mfzUnTR0yc6Sa-v2-6x50qS3AIepbwFUYiABiJEC5T2epntW6ZR6zzHAFDzAvK-4zBv92l_k04XM20X2dzd18sYJF4r3gmC8Q9BFp_unQ8Q9Q5Eltjw=w784-h1041-no?authuser=0)

This is showing the fit of the stop to the push rod.

(https://lh3.googleusercontent.com/pw/AL9nZEXOpUm9jE7MaUkgEkMEkw2jECxeAPa-3kSsb5Z3286snoGQX1qo4_DWpnjFgXTJnBUq5nNv8eRifppWfdOdvcDSVi5a24cWuHLmhx6Yv9aOGP0wWtj81i6Q6wb3ZryHk0PSmdIxWdJoFpiLwhkG3LEK-g=w784-h1041-no?authuser=0)

And finally, here's how the assembly goes together, although I forgot to put the stop in place for this pix. 

(https://lh3.googleusercontent.com/pw/AL9nZEVcuz1Ps8IALrUnuLYfzymo4gqZsY8N7cljTpwAHTBbx6wEjeAJ2dZ6EQcU6IptpOAlmfeQ9dMyjGGLAGaNtqnkPYC2bucox4hhgtTTUPOZVRB0ONI7GjIPAIGL5e4zQV1QpdXJVK1CrKjyvmbkv63YJQ=w784-h1041-no?authuser=0)

So that's it for another sub-assembly for this engine.  Onward and upward!

Enjoy!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Charles Lamont on November 21, 2022, 08:58:05 AM

Some fiddly work there.
Title: Re: Farm Boy #876 - Mike's Build
Post by: RReid on November 21, 2022, 02:41:53 PM
Very nice, Mike. Still following along and enjoying! :ThumbsUp: :popcorn:
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on November 21, 2022, 09:59:22 PM
Gents, thanks very much for watching this build!   

Now, on to a few more fiddly bits, plus a failure!!

None of the actual operations shown for this as it's so simple.  This is the 'Secondary Exhaust Valve Push Rod'.  It's just a piece of 1/8" drill rod, trimmed to length and threaded 5-40 on one end.  The only change I made was to make the thread longer as I want to incorporate a lock nut to prevent rotation of the clevis/rod interface.

(https://lh3.googleusercontent.com/pw/AL9nZEU8ABubWvVYkXvwpynvZ3UCYTPRUUl_QKedjuChCvE8uwo5wMYpuYHLpbFRWKpR7oVSQyAkQQLZiULWS_VXczWJ1pQtgZ8_TcFftLyJ0_I7N0nNjFfzjuFFdcSH1g5simZ7NzB_7kOR9F3aat3Bel_j-w=w784-h1041-no?authuser=0)

Next is the push rod clevis.  I'm sure you can start with a piece of square rod, but I decided to start with a piece of round rod.  Here I've just turned the lower portion, which remains round, to the spec'd diameter and now drilling/tapping it 5-40.

(https://lh3.googleusercontent.com/pw/AL9nZEUihewAc73bohD55ekl2_ki4C_pLOFmhrvdTY_vHcxmlN7vNzdgNr1z6IzeU7Lghj2HU7vVtSA7zsP3GLno5UjL-hg9YNIFkqkNyIJQWkFkzhOj-h2kYZ0LcREXkqZ5d6SrdqFh7KeGd-eQTP9hB4AyNA=w784-h1041-no?authuser=0)

Next I placed the part in a collet block and squared up the outer dimensions as per the drawing.

(https://lh3.googleusercontent.com/pw/AL9nZEXJxxKN4PAYo8dxBQhR_Tf4Kwpf_dsGYbXNU01eCYNHrydOnj6YVM5BPFA7xktU8NmBiQ-CJetWbWvUp4cMB-KSU3pyVMwWUzZ2vhKX9BQI5ZbwzD11qeF0GG5ulGYW9s198NT-zwkVH4H8gm0BWOncuQ=w784-h1041-no?authuser=0)

I didn't show the operation, but I did reorient the collet block and drilled the thru hole for the clevis pin.  I DO show the disaster though!  As i was making the last past to mill out the slot down the center, one side bent which of course destroyed the part and also the end mill.  A sad day!

(https://lh3.googleusercontent.com/pw/AL9nZEX-i5CFOfNvHRZSQ7pIPkgBx4EZcSYVmks0TBm6ZsoEDHxeBSTEVM6S0-t-VANoygAIu8l0PFSfzxwduO4HA7Vm4pqFuZq1_Hprup2agsZCb8HaoRnmEsSN5unyOI7IriWQAFsdGrHQ5xyEH3aPohlL9Q=w784-h1041-no?authuser=0)

And here's the aftermath with both bits clearly shown.

(https://lh3.googleusercontent.com/pw/AL9nZEXvsO3PA4v7Nu3NOF6UsK9QR70h1jZIPIxR--c9dTlPIzve8IfQmbhRL0SfEyX9fgoxHQ85t7BMKDNou9E2mrSBc1XapV1AxGPg4iyWiwPOEdnVMHW8NYo9AtaK75VQKKkGu6UchfrU_lMJb0TY32k0zA=w784-h1041-no?authuser=0)

I really don't think I did anything terribly wrong as I was taking very light cuts at this point.  So I took a bit of a brute force approach and simply increased the thickness of the part by about .020" overall, so about .010" per side.  This gave the part a bit more strength so that I could withstand that last bit of milling without failure.

And here's the part, version deux nearing completion.  For this attempt I used a 1/8" 4 flute carbide end mill.  Everything went fine this time, with really no change in technique, other than slightly increasing the part thickness through that dimension.

(https://lh3.googleusercontent.com/pw/AL9nZEWljkOQaIgekFzSnstv-ParrMCA7SrCpIK2iFPip1X2UBszL_qtl0TpgqW441L65rR_Lya9h0bqw-8YC4uVuk8eTUfx8zEaMyI6JFXPwbRTXlsOCY0IGHq1l9BN8tZLWAly90mtYOwC6K23RPJ1jDSnYQ=w784-h1041-no?authuser=0)

And here's how the parts made so far look in combination. 

(https://lh3.googleusercontent.com/pw/AL9nZEXeE2-es7ItCX73F-I1AGmHzplbz4flxsDvVgvnhTowl4MgWTGj5gaFK0fY7GpdMiOKDWn09GjcPIgIEKjAXKEu8ukxCheJLK6AYFX-0C2vp5fWB0AtWGVtkTzLXV-uR-QQe8cHcP24goBMUqmAvYRo0g=w784-h1041-no?authuser=0)

And here's a closeup pix of the clevis installed on the push rod with a nut for locking the assembly to prevent rotation.  I rounded the end of the clevis just marking it with a radius gauge and rounding it over on the belt grinder.

(https://lh3.googleusercontent.com/pw/AL9nZEU7x0bM0YosOfSY8DWXaFRK1FaZxa8Tp_TXV5FFk8u84ZRwoFjBrTLufs3NiYOAaTI2vwIwERY0U7qH1s78S1J0aYn1-HPgKmIjbiTQu1DM0DvVVISxLO9yp8khHTn43hmgAUQcuMsaD8Th0yrpuic2zA=w784-h1041-no?authuser=0)

I'll quickly document the build for one more small part, the Governor Catch Lever Block.  I started with a small block of tool steel and milled the overall dimensions and here I've tilted the stock using an angle block, and am about to mill the angled edge on it.

(https://lh3.googleusercontent.com/pw/AL9nZEV0QHB3kWXVxD6ZxgmCgV7ncliA_xqOdbwlfa8N5BYhhGemnZesYBj5eMydU1hkoEDU1KNqQ7zUtXOZ7Hut8yXzvLfEs14ggelBxPkntoqfxCN5z05wo-hvYoj3JNcOyEYiUzp1QrsyA7G5Hy80aqTANg=w784-h1041-no?authuser=0)

Next i used a slitting saw to cut the part off the stub stock.

(https://lh3.googleusercontent.com/pw/AL9nZEXn51aumVQFALH5GCgY878Dzp0TNetbEPpNv-DUdUnyObFSyDD1JSTtRx3anyEq3bRDsi9IXUwHhoDA5KQ_AIYsc5xT3d8pQtQc3PBSUTc8BqjHM2WU5VJxdiX9bzL4Yn3zPb4tLR_3wCBlpyGl48tWww=w784-h1041-no?authuser=0)

And lastly, mounting the part in the mill vise and drilling and tapping 2-56 for the mounting hole.

(https://lh3.googleusercontent.com/pw/AL9nZEW5-RT-Gvi0P7LhLvc0GkMAwB5qb3dgrbR6CjzSszZkaqeJejROY_B8_Eo6FZ8WSj5u1Ka3y-cqIOqhZHnmoNV_WISvtGHE4_r6zZsSEc9W-Iyki1On7rx_0ALAMm31GlT_PJWUo9hdrDFQhRDmrcOdZw=w784-h1041-no?authuser=0)

And here's the finished catch block with a 2-56 hex bolt installed. 

(https://lh3.googleusercontent.com/pw/AL9nZEUCEkYvk4whdgu0MiCbwUnhGYHxipzm0MYR0Vqxfo_NmrsTov7LlXyvlEyqX_AyDhJ2h_OQ8SjayahisrvFodJ6kWyC54M2ZuJZWtEMLNrBTMqUyOFK8CEBnUYNU0DEiR4yA22s04QGyU8xKMPsbZTJmg=w784-h1041-no?authuser=0)

And that's it for today! 

Enjoy!

Mike.
Title: Re: Farm Boy #876 - Mike's Build
Post by: Admiral_dk on November 21, 2022, 10:04:32 PM
Breaking the Part is bad enough - but killing the Tool too - now that is Very Annoying  :wallbang:

All the finished Parts looks very good - so at least you are moving in the right direction (even with one step back)  :cheers:

Per
Title: Re: Farm Boy #876 - Mike's Build
Post by: mikehinz on November 21, 2022, 10:44:41 PM
Breaking the Part is bad enough - but killing the Tool too - now that is Very Annoying  :wallbang:

All the finished Parts looks very good - so at least you are moving in the right direction (even with one step back)  :cheers:

Per

Yes, breaking tools is annoying AND costly!

Mike
Title: Re: Farm Boy #876 - Mike's Build
Post by: Kim on November 22, 2022, 05:19:04 AM
The parts look great, Mike!   :ThumbsUp: :popcorn:

Sorry about the broken end mill.  That happens.  Guess it's a hazard of our hobby.  But always a real bummer!

Kim