Model Engine Maker
Engines => From Plans => Topic started by: mikehinz on September 22, 2021, 03:03:57 PM
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Hi,
I'm going to start my build log of my version of a Upshur Farm Engine. I've already done a good portion of the build, so I'll catch up with the log and photos in the next few days and then will start the more or less real time updates.
Just to describe my approach for this engine: I purchased all of Upshur's plans and decided that since I've never built a hit-n-miss type engine, I'd try that. But to me, the Farm Engine plans were a bit confusing since several different versions were all mixed into the same set of plans. So, I modeled what I wanted to build in Fusion 360 and then generated a set of 2D drawings to do my build from.
Here are changes that I decided to make on my version of the build:
- My version will be an horizontal air cooled, but will keep Upshur's bore and stroke.
- Use roller bearings rather than bronze bushing for the crank main bearings.
- Crankshaft will be a built-up fabricated type rather than turned from solid stock.
- Add bronze bearing inserts to both ends of the connecting rod.
- Use an o-ring for the piston rather than cast iron rings.
- Make the crankshaft more easily removable by adding separate bearing blocks that will attach to the frame via cap screws.
- Use cast iron flywheels from Martin Model, slightly larger than the plans call for. They'll end up at 4.125" diameter
- Change the gears from 48DP to 32DP.
- Use an S/S hall effect base ignition system.
- Add a 'Brian Rupnow Design' starter hub.
There are a few other minor changes, but I'll note them as I post the build.
Hopefully this will be enjoyable and maybe even useful to some!
Mike
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I'll definitely be following along, Mike.
Both the built-up crankshaft and the O-ring piston are shown on my plans. It will be fun to see how your changes compare to my build, which is mostly as drawn, except for some cosmetic changes.
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All righty, I'll document the engine frame build as I did that more or less all in one go over a couple of days.
As all project start, some 1/4 and 5/16 AL stock was chopped off with my small horizontal bandsaw. Here's the rough cut pieces laid on top of the working drawing I generated from the CAD model I created in Fusion 360. You can see some of the changes that I made to the frame design to accomodate the removable bearing carriers. The frame is .25" and the bearing carriers are .313 so they can accommodate 2 flanged, sealed roller bearings, .3125x.500x.1875.
(https://lh3.googleusercontent.com/pw/AM-JKLWWga5-AC9544h8rdPHp95tt0uF2pDUWG9kPDwi6ioHM3dNlGbhMUtZPkpHAeEklR9-WTyF3IrndmADu3VlDim00T0tL5New-XflNcJUFwzvqXo57Hp5RnSTunw82G5X7nWgVJF4kFru73Tgi7onwTF=w951-h963-no?authuser=0)
Just one quick pix of the way I did most of the frame pieces. I used super glue and mated the rough cut pieces together to minimize all the swapping in the mill vise. I normally detest super glue as it doesn't hold all that well, but since the surface area is large and I'm gripping it in a Kurt vise anyway, I figured I'd get by with it.
(https://lh3.googleusercontent.com/pw/AM-JKLUr1bZsFQsAlxG-ah9Uj65M0G2KCAe6O7hmAgSPe8h9s5CWouotunPe-38pL6dgYzjQ3w4HLlM_f_W735Aspqmkzuhz97SLH7r8nTB76WSVKfsVrjehn9niAWx6AAr0W7TatDpWk_m2p-SgUjjd0Z5R=w723-h963-no?authuser=0)
A pix of the last operations on the bearing carriers. I'd already drilled and reamed them and am drilling thru and putting in a counterbore as those blocks will be attached with some 1" 4-40 shcs.
(https://lh3.googleusercontent.com/pw/AM-JKLXZG--qDtFUOvUf7R5pAAQmVNxodLfaDJ6LpmgAgt5NS8QISt7GPAJWxMRMtUpH7mvdZlLhL4IwMvPxMbYDPJPcPgJk6HtQrElzsyIOHZhaBo11LWS7Bbfs8cAHXSISGYrtoSfF9dIvUFFNh-ebQ5m0=w723-h963-no?authuser=0)
Here's a shot of the 'main plate' after drilling out most of it then boring to the final size of 875"
(https://lh3.googleusercontent.com/pw/AM-JKLXpcM6urCq-KCaNpcl0VQ3pN-Bm0TJJPlYAh7AzWBtOF2demvUkpiXu7J3cA2LcUIe2mK4exSEFcYwwboD3E4kiLEXuvt2su4YDXUoJFxcgz8L3bQNSmAYT1aS4tat4FyuqqOFuegawuvKlBTR5U9ab=w723-h963-no?authuser=0)
One of the last operations on the side plate, milling a 45 degree angle on the upper rear corners of the side plates, mostly because it looks better. I set the angle with an angle block under the frame side and tightened the vise down on the plates.
(https://lh3.googleusercontent.com/pw/AM-JKLVIH9K4y7Z7t-ixfkoS5nMbceC1zKhRrCFbvuivKvZKBFyRWg3pLg0MFtTld1KCUGPKX_MdUgdSgNwoqAV47oMZm_iKciRAFfGAtFYbcw6oneEfOJ7N0l3ajXu9m82QhJPhMG7YkiFDUpHYsVImnO1A=w723-h963-no?authuser=0)
The frame plates and base with work done so far. The surface finish will be worked on but not until much closer to completion. The front main plate still has some detail to be added also.
(https://lh3.googleusercontent.com/pw/AM-JKLW6t08WJbN30sEJmIJ0-Tbk84SOCYVoUMybMXO8vo3s4lXSLMEx58msRXMW4Izv4025CKBQ_ackYUmzQVVeG6xPtpUol3WaRtYwGNBrlMnIDr1rSOQdOf-hGcZBDnK8WCeJt72IqmaXJjcG_BLTBspX=w723-h963-no?authuser=0)
I didn't show it, but I drilled and tapped a hole in the center top of the main plate 10-40 (same as 3/16-40 as near as I can tell) that will be for a PM Research drip oiler. Then I made an alignment pin for the center hole of my rotary table, mounted the main plate on a piece of scrap AL and milled the rounded top on the part. Shown is the mounting operation in progress. Process involved center the rotary table under the spindle then stepping off in y axis .937" as per Upshur's design and rotating the table until the top was rounded.
(https://lh3.googleusercontent.com/pw/AM-JKLUR6vZCEbVhqdABx7TsPlUzhnmbMyBTgcW_aF4l5m_O48tVhOjktS1Qdj3DUNZXxGy8sB9I_dBNvyO3e60g_82a-15QRTGbWRatTD1hHM3tApcgcn3P5QlXvSY7c_wzycCfuirzUBEhz-bhL-Kpz36o=w723-h963-no?authuser=0)
I wanted to assure that the bearings would be as close to aligned as possible so I assembled the frame pieces and reamed thru them both with an on size reamer. I'd left the holes originally just slightly under and my hope was that this would make them as close as i could get them.
(https://lh3.googleusercontent.com/pw/AM-JKLWE1riocgukDfG5sIifh9MrkKre2jwySnbSWciknaDtwC_i_XjpNP9t6OX6gw1B_j9sNCTr6gk5He9zgPlQgNeZK2x_TYO4bz-eC8mY_o4322vj84mE7moYCyNhUHFDic7Ubvzki5BAzGFBnvdfxhb-=w723-h963-no?authuser=0)
I also not so cleverly forgot to drill thru for the camshaft mounting hole and for a tapped 4-40 hole on the other side frame for mounting the hall effect sensor. Soooo, after I found my omission(s) I located and drilled/tapped those holes.
(https://lh3.googleusercontent.com/pw/AM-JKLUvEuXhGCMT_4TvlXt4HxKkOxkO6Tu_EY2nVLtlqtPmKTklxm9zjkbeuTtx__gp4B86DQMS4xVtLFF8IxCmm0kOe8eS5BlF8gUKsxIdthlz01Xq37yu8C1md0OXElUd6uH40A-k95-pIjWylY5hIHb8=w723-h963-no?authuser=0)
And that's pretty much it for the frame. I'll show it assembled with some other pieces as this thread progresses.
Enjoy!
Mike
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So today's post will be on making the cylinder. This is a horizontal air cooled engine, so the cylinder for this version is fairly simple. So, here we go!
I started off with a piece of nominal 1.5" cast iron and centered it up in my 4J chuck as best I could given the surface roughness. I tend to get material from Hobby Metal Kits out of Watertown, WI. They normally sell in 1" lengths and their shipping is about as cheap as I've ever seen.
(https://lh3.googleusercontent.com/pw/AM-JKLUxr9t0xVw83QWxqP9linbwhS5fhR43MgD-jdjur2ZTI7tMi803ouotN3lRwlQyivx9Vk6ontLmA1m0-HOELJzBjAa8DVCPQLjFIwBb61mkb0te5GHMjzeQ3fifkX6UrVjC55bx-Fu0TAUQ9Ezv82SA=w703-h937-no?authuser=0)
Then with a carbide insert tool, I turned all the major ODs. I love the way CI cuts! Very easy to cut and very nice surface finish typically.
(https://lh3.googleusercontent.com/pw/AM-JKLViaS_bjTkxFM6y1LsQLfgMhIsEdD1Kj4VRoLXeAnLONWjkuB1Sz2QUPj0lcy824QZjm5dEhfsGsEZgVfoYL737dofjynUVa8fRnZqBi4wK9ybhnmmMD4L894T_r3HOBDz3_psjwQg1kHLZogNOY74Q=w703-h937-no?authuser=0)
I made the air cooling grooves with a 2mm parting/grooving tool. I changed the drawing to make it easy for the tool I had, so the grooves are .079 wide and the tops are .079 side (2mm) so it makes it easy with the DRO to space things our properly. Then I just plunged straight in to .187 deep as per the drawing. This went quick with the CI and a carbide insert.
(https://lh3.googleusercontent.com/pw/AM-JKLUxZHL_DUafCuUHGJpurKfMQmKbmZFavBEqyTj40yWL59WCCH0Ez7fCHFUa_4qc328vU0y0cJ62L4AfpXYMEKuxsHZCeuXax6-dXopCfu4kHTkn2kxzEhMSIWja9Pt00kRcyZi7bQ4MnYhQzZ7iOWnw=w703-h937-no?authuser=0)
Then I center drilled and drilled thru with a smaller drill and then finished with a .11/16" bit. Again, pretty easy drilling at around 90 rpm. No lube.
(https://lh3.googleusercontent.com/pw/AM-JKLXDe88qX8A37eodDh7089Jd31kwMgHuxJ3dMJuWSLg2XU6PXitLMfYOrO2tt2dSHU5nixO0ZRhhcM_8n2PuRRO3DgH5jspf9vA8tIt1e_0EovnS3IBrabTjVHKjFz1aF4yAFQANWUIU8B5Jd_5bjCRd=w703-h937-no?authuser=0)
Next was boring to just under the final ID with a carbide boring bar with a carbide insert. The finish was pretty good after the boring operation but I'm going to lap to the final ID after this.
(https://lh3.googleusercontent.com/pw/AM-JKLVEjt9aSvt0fvr0bUxP3NBLxWQ_g2Fx-m5FxicjFvLQZvUXIvfLtEwE-AK5lmwK7sRkoLWJxqxhMxFsDIft86UHKBrB8gBWWKlROM0FI0CKrNC_K73OHCpca7eE5gZHDoyPVv3t3q0Y1ZcpmatDMeVr=w703-h937-no?authuser=0)
Ended up at .749" which is right where I wanted to be.
(https://lh3.googleusercontent.com/pw/AM-JKLXLoCz7xKi2EQlVYa4aoOhzTUKl0M4TgrT4bmBQ5z-La3TLYq8pLfFv7llmlTnIZBPaK5i0MNWNZB3_WqQfsfn9DT5gZIzi4zS9v7CPqxbXq7pKqbNu0eV0J13DZF0EhMly5b9nfMdOUpasXfFhRMI6=w1250-h937-no?authuser=0)
Parting off with the same tool that I used for making the grooves. I think I had the lathe at 430 and the parting worked well at this rpm. Again, all the cutting was dry.
(https://lh3.googleusercontent.com/pw/AM-JKLXWDRa2sz-UKwOCrWwoEp_hNeIIItJrIosWD4iG5xrU7Tx-ARq5p8xvvDN2MYv7WudmVqLgeni4hhryytovxR7LPDptBFICBLUng_hzayznnwVhqQtzRtV7cGZuuKIIeYK2jEOIWylzi1IGLBrISvRs=w703-h937-no?authuser=0)
Over to the mill. I mounted the cylinder in a collet block on the 1" diameter and milled the .187" slots on each side for the mounting studs to pass thru from the head to the main frame plate. The collet block allows easy indexing for the groove on the other side.
(https://lh3.googleusercontent.com/pw/AM-JKLW57iLjii0yhap-AeNUkS4OqoG5KCmrcFevVzKXqvL3_Cn7YjVwRuj343e1UYYkGuiXipNpiP8xYKabHAsXIordYy-Azf6XtY9PXtxE5aJOAqflXBbqyWpLxIny3XRp_X4So1MucJFoeyJ7GE000tS4=w703-h937-no?authuser=0)
Next I mounted the cylinder on the engine frame and drilled thru both pieces 1/16" to create the oil hole in the cylinder. Then I drilled and tapped 10-40 in the frame only to mount the drip oiler.
(https://lh3.googleusercontent.com/pw/AM-JKLW2WiVjSBDYy2iLpDc32TWq_C-ztkjULBls_PG4n-IXFomfWU8r5TI06SpQkBAAM6nVWVYElAHIKZKt3sUeKhjJwsnT-5uCbCE3gUXvYSYsX1paEY6ROCql7ik3DMDaaxPRb6jTYIOgTFUC_QUhfmTr=w703-h937-no?authuser=0)
Finally I lapped the cylinder. I used a brass lap turned at the slowest speed on my lathe. I used Timesaver compound mixed thick with a little oil. Just a small amount mixed in a small paper cup works well. I started with medium grit, then fine, then finished with extra fine. I held the cylinder by hand and activated the lathe just with the bump button so I could quickly stop the rotation if it became too hard to hold. It's interesting that you can really feel the lapping progressing. At first the part is easy to hold and you can almost feel the high spots and you have to tighten the lap quite often. Later, as you progress to fine and finer grit, the rotation becomes very smooth and it gets harder and harder to hold as the lap is tightened. After lapping, as close as I could measure it, the cylinder ID ended up at .7505" so I was completely happy with that.
(https://lh3.googleusercontent.com/pw/AM-JKLURk6yF9TNsN05gXNXzd7FWQuc1BN6YcHSFMGWZUznmMVcjW4BO9-lleb75XXm3A5uN0atN3VVw76g5eqDMGmZRcI5NUhOrOMbi9edRtnwFlHMt4b8r6hKJ6Hmrk8c-KGKPq8eWrUxW1bJneByblnBa=w703-h937-no?authuser=0)
(https://lh3.googleusercontent.com/pw/AM-JKLWtgrgv8TAp_zw-_I4gNjgsFvmYiphDtcxYcyDcgvLXyEeI3t1Rj2dSvYx5mD7dfgBDWerujnitKsB3eP0TcQTWHgsjugz-UEqfgnqDivrUpAXYwKz4of018ay78FLUvmn5FeDO48f0KDJqWfFCqhBF=w703-h937-no?authuser=0)
Upshur's plans call for a cylinder liner with pressed on or Loctite on cooling fins. I'm sure that will work, but I think doing the cylinder for a solid piece of stock is easier and for sure the cooling will be better with a one piece cylinder.
And that's about it for the cylinder. Next up is the head, but I'll post that in a separate reply just to keep the process at more clear.
Enjoy!
MIke
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This post will cover making the head for the engine. I have to preface this by warning "Here Be Dragons". For details see my other thread about plugging a hole in the head for details. I'll mention now that I'd do it differently if I ever do it again end up remaking it. I'll mention why in the body of the post below.
The process starts with a piece of 1.75 Al that I had on hand. I chucked it up and turned the OD to 1.50" and parted it off at .562" OAL as per the drawing. Nothing terribly exciting.
(https://lh3.googleusercontent.com/pw/AM-JKLVNP4ouvsKfReQRdOKgm-EubmwXKsgvd3afME4gmwbWHJbMXq9RQdVDgqEIhEmJuu1PQDtSbuZuWSVJ-uugLeIr2-80F-IpZdv9YEmdnleiqGpjeJpGyobe2VBbO49aZho3ealXp-Px1aTYWJfNKGK2=w703-h937-no?authuser=0)
The head is illustrated on Upshur's plans on pages 12 and 12a and I was somewhat confused by them as there are a couple of options and some of the drawing details just weren't completely clear, so I carefully modeled the head and generated a drawing to make sure I understood it. So here's the drawing I generated showing the side entry plug and adding 10-32 threads to all the ports. I did this since on my Webster build, I had some trouble with the exhaust and intake adapters loosening after I ran the engine for an extended time. I figured the thread with a little Loctite on them would be much more secure.
(https://lh3.googleusercontent.com/pw/AM-JKLW9F5Xhw2K4IpPRaF4cOZ-vV1-8DC-OUiJwkpZcUuKIPH5PtIvJLS6f_S4aBx-gS9cqXTKlXK6d-LRpC1RBHq5df7vi1hCyqANfQ6vVvqt31Tm0Fhbje2C7bO8SzwEIOR8Oa-b1r_dL39VQmdaqlgRF=w1250-h937-no?authuser=0)
Then over to the mill, holding the part with some V blocks and AL packing. Holes were positioned by centering the part under the spindle and stepping off using the DRO and center drilling, then drilling, then reaming as indicated on the drawing.
Now would be a good time to discuss the issue that I ended up having and what I'd do different the next time. Upshur's plans call for drilling thru the head to insect the spark plug hole and then plugging off the top of it with a small AL plug Loctited in. That turned out to leak and involved a repair documented in the other thread.
I'd recommend NOT drilling thru, but turning the head over and drilling ONLY from the bottom side so as to avoid a thru hole. This will eliminate any chance for leakage. But you need to maintain orientation and center the work up again. Also, Upshur's plans call for a thru hole for the rocker mounting post. That ended up working for me, but it would be better to NOT drill thru, but maybe drill .40" and then shorten the rocker post by the same amount. This again just eliminates a potential leak point.
The the alternative is to mount the spark plug thru the face of the head. But I didn't like how Upshur did this. I did an alternative design where I moved the location of the spark plug and angled it at 15 degrees so it fully intersects the bore vs in his design, where the spark plug hole is half obscured by the cylinder wall.
(https://lh3.googleusercontent.com/pw/AM-JKLWxN6MLbWefvYPohEteoeC4Qb3FQcwt-aX2l0wi2V_mfrcNzcHttVsEBRHgqJQx6BFFLCF_46AIhFsCuY8jlwFHlOlTsHgTM0vFGmylYlprUjqist6LedxLqTVstnqYor45xOj3La7IkNuJBkG34d_R=w703-h937-no?authuser=0)
To drill the intake port, I just flipped the part and held it in the mill vise with pins thru the mounting holes and then centering under the spindle. Then it was just a matter of drilling to intersect the bore from the face and threading 1/4-32.
There are 2 other intersecting holes that need to be drilled. The exhaust is at 30 degrees from horizontal, but the intake is 39.8 degrees from vertical. There are several way to do this, but one of the easier ways, at least to me, was to create a a 39.8 degree angle block. So the following pix show how I did that.
First, recall what your high school trigonometry!! I did the calculations and then drew it up in CAD to generate xy coordinates. Then I cut a square block, and it's important to make sure the corner of the resulting block is really 90 degrees. Then using the DRO, locate each of 2 holes and drill and ream for a .250 pin.
(https://lh3.googleusercontent.com/pw/AM-JKLXGgNzK0JviuPmcuPebTHPx8qPS54Yh8BovqjJG9PenKD87RQy4QcIyXeHs3WZ6rBbQCcCOw37ING3voXW_1wGK2y64J-1VmSNiyq-5mg6J1erIr6vhVNdLMDI0ff804RS4s8fsMoC3oG5N3yLrHqey=w703-h937-no?authuser=0)
Then insert 2 accurately sized .250 pins, turn the block so the pins rest on the vice jaws and mill the corner away.
(https://lh3.googleusercontent.com/pw/AM-JKLUmXJ7cJ_qc5S4ejZ_wDtIKrLLJBZjY7rd3SRoArLbzpJqQFpiom5ywWLrbCTC-ub2-ST2P2B8hu4RsGa6DRoia5DWh9yNk-9jKLyYu3E0wlkYF1BOgOoGAfTnSaS65A8Tgxqsx3Nfy_HqwtWHyI78j=w703-h937-no?authuser=0)
And here's the resulting angle block shown against the drawing.
(https://lh3.googleusercontent.com/pw/AM-JKLU0p45tjqhKC03f-WeJfjlHfVcCLfciKpoZ3B9A_7Lvde7uoTLyIhH1b4iWKLc9tykmc1z4mjV9Z7q5Cm1wC4OKNh99LgrUyXruvrPqPNzVb0qYgc9jjhwZf3bj-0t1GxOMCFWLJsZdJIgEoiJ_ztev=w703-h937-no?authuser=0)
Showing actually using the block to set the head to the proper angle to drill and tap for the spark plug hole.
(https://lh3.googleusercontent.com/pw/AM-JKLWmej3cI363HaVeGrb5orz23ROS2YsJSGrAIPmvZnO6C9AkeDUwhEMLUq98G4vJbMgPDR-tYpMBz6qQqRqjATG0Vukn1uJVjuSV7TYQfEQaNZbygG2Niq3cySHeonVm4iW4tOBG9OyHlq-Z0rD4RADV=w703-h937-no?authuser=0)
I do want to clearly state that I claim no originality for this procedure. Many other's have made angle blocks this way but I thought it might be interesting for anyone building this or a similar engine. So again, this is not my original idea, I just used it to solve the problem I had.
And here's the head completed so far, with the spark plug installed. That's one of the Rimfire plugs with a 1/4-32 thread.
(https://lh3.googleusercontent.com/pw/AM-JKLXioi0JZC1EBQ3HB-Odpj5_QsYi0R24xQweGglANMxvjrGd2WjK8p-dyXiQYu--W_cExacQjk0A4JoshIhNcmUC9vxo1QQiWUAcDAYJd9wKAYSH1FofjTyy6Z4G4V14AmvKWCveL7B9zN-2_buxGU3K=w703-h937-no?authuser=0)
And a pix of the engine assembled with the parts I've made so far. The drip oiler is from PM Research. So far, everything fits together!
(https://lh3.googleusercontent.com/pw/AM-JKLXvpM_luR47r0zXT9yle_QtBmtZEUO10BIovARvCVADo-tf31reFTrqE_17ENSZDnWinEcn-x4clCnvqdq1fwaI_BJvFcLNF_v3Ie_7jGrvzN3m3rl0ku8BsdgGacD3Zk3X-zLSCoHqfDCu9AFuD7d_=w703-h937-no?authuser=0)
That's it for day.
Enjoy.
Mike
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Man - you're working your way through this build at almost Chris Rueby speed ;)
and no Elves to help :Jester:
Nice description and parts :cheers:
Per
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Damn some body is picking up speed here. Parts are looking great Mike….. :Love:
:cheers:
Don
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Man - you're working your way through this build at almost Chris Rueby speed ;)
and no Elves to help :Jester:
Nice description and parts :cheers:
Per
I resemble that remark! :lolb:
Very nice work!! Watching along. Hey Per, pass that bowl of popcorn!
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BURP ...!.... what popcorn .... oh, wait a sec - I see a fresh back of corn .... now we just need a Pop or two :LittleDevil:
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Looking good :ThumbsUp: :ThumbsUp: :wine1: Are you using an Acrolap on the cylinder?
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Gents, I'm not all that fast, really!! I have been working on this engine for the past few week and I'm sort of catching up on the posting. But thanks for the thought!
And yes, that's an Acrolap. I have several based on projects I've done in the past. I find them to work very well and they're not expensive, at least IMO. I always use Timesavers lapping compound, mixed rather thick using just a bit of oil. For a cylinder that is bored to size I typically start with medium grit, then fine, then finish with extra fine. And the finish ends up really good IMO.
FYI.
MIke
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This post will describe how I made the crankshaft for the engine. I'm hoping this technique will be adequate, but I'll not know that until I try to run the engine. I'm hoping for the best!
I changed the dimensions of the crankshaft to add more length to the right side of the crankshaft as I'll be adding a disk with a magnet for timing and a starter hub to that side of the engine. Also on the drawing you can see that I'm adding a 1/8" milled keyway and will be broaching the flywheels and using 1/8" keys for torque handling. This is just a piece of drill rod, not sure if its O-1 or W-1 but it's cut to length and ready for further operations.
(https://lh3.googleusercontent.com/pw/AM-JKLUmGi6glXecfQ6S3_rbV3LMfxaSQaEu-kzjjXgjseUVSzXZoBG4usvEXQAGz9lA-wA7Rl60wGrvUwChRRIsorDY_ydNX2DBXozNGTJsrjvzyhHPZqMVHLm8kxqaS3NofLoK97JuQ_7ErN4msQLxF__j=w1248-h936-no?authuser=0)
I showed making the bearing blocks earlier, but I wanted to make sure that they were aligned. I installed the qty 4 bearings in the blocks using a just a small drop of Loctite 603 so they stayed in place. The bearings are flanged, sealed 5/16" x 1/2" x 5/32" Trade Number R1810-2Z. I tightened all the frame plates down and slid the rod thru and it fit well and rotated freely! You can also see that I drilled a center hole in each end of the crankshaft for possible use later.
(https://lh3.googleusercontent.com/pw/AM-JKLUDijznCt9XEcXIt9f-CBwhdVaMpOv7UgJOg2ptfuwu6gDSe7ZrZr609dnUiJ7ch7zv8I4FLCv5KpOXEOQpxGbDeOjEAPBWsZYjPSRaryy8Cf03HWrsYjKfRJZHdwrlnYYfuJyo32G3e_fUT5-X92F8=w702-h936-no?authuser=0)
Next I cut and trimmed to length a piece of 5/16" drill rod for the throw. Nothing terribly exciting here.
(https://lh3.googleusercontent.com/pw/AM-JKLXsSNE-fmdD1ZRknUnioC--CUtcH1vwcybXMKcRGQ5LlhlofjyQ-IMpj2llYdWNt2qg5cQdYQ9Ql_Eo-H0kHINYFuoR9zSSFzRLgelm1VR6pKT0-62PVipTx8K-haDOt6FeYr47ERNasBVFuMI5SxsC=w702-h936-no?authuser=0)
Next I sawed off a couple of pieces of 1/4" flat stock and glued them together, just to make them easy to mill and to make sure the holes were accurately aligned. I didn't take any pix of the operations on these pieces, but it was just milling to dimension and then locating and drilling then reaming the 2 holes through the parts.
(https://lh3.googleusercontent.com/pw/AM-JKLVFy7DypBqH9uwAFUnaycxgtCT0lyraCFsgioJcE5glw_UP6n8ap7CivB4DikMSk-IHTUMK9B036XFPHJUBAP9ybNeGTaacJN8yXSbDHNPJpI3mmCVj8eLD685v09Ugut1O6d4mFCzkYtWg6h8txsjL=w702-h936-no?authuser=0)
Here's the milling operation to put the keyways on each end of the crankshaft. That's a 1/8" 2 flute end mill, running at something like 2500 rpm and I'm using my Unist MQL system to keep the work lubricated and the chips out of the slot. I think I made 3 passes each about .020 deep until I got to .062".
(https://lh3.googleusercontent.com/pw/AM-JKLVawdDVQYsGgUystnhoIf5jME7fn4BdDFV7aG69-9IUq8KT5PDmL3CmIfO6NqJY6nbOdHAxUJ9n97MwRiBxx9VQDz70IcpNC6ic8RFM7gdRc4pddL7Zkl-AcXn3860_B6nw0youZw2kiKo3jE7M__mU=w702-h936-no?authuser=0)
All the pieces laid on the print, deburred and ready for assembly.
(https://lh3.googleusercontent.com/pw/AM-JKLU1h4GLTI_cXOeUMv_0FJ_TUEVafgi7Rmmlq7YzFOHiflfiSJJHs-gyK6Uz1wOLNoCKkWkW5K4bygeShQuNgbhye10kycmMKotVnmZv1vuXDXgCiCViVQXV1MeDe2MaR_3Q20Kt6JS3mAy8pVmnXHWr=w702-h936-no?authuser=0)
To assemble, I cleaned the parts with acetone and applied Loctite 638 to each joint and slid the pieces together, maintaining the spacing at the throw with a couple of gage blocks. I assembled it on the top of my small, cheap granite plate to keep everything as well aligned as possible.
(https://lh3.googleusercontent.com/pw/AM-JKLWROqN5sK5vsPP66tojj5rNF6U37YhTUDmNGyl_TT1kryd7axcDpKFC7wS8TQReKjT21cr82nnJ4hHkl20VLMlWN3pzt0DyhBnEeYwkL9IxJvASVHEHHyqqvj-ztC8fc1pG20Sze-4rHrzZzuDs1B5x=w1248-h936-no?authuser=0)
I drilled in 4 locations with a 1/16" bit in preparation for pinning the crank joints. This just involved finding the edges and using the DRO for positioning.
(https://lh3.googleusercontent.com/pw/AM-JKLVLmuLFiXlMpjS_V8GVb5HT-LGMABAmBiQ4uTUG1z2vCkG0Hvw5AKk1x3STz4RWLCGQLcGQ3uejd-Pa2FdWLBorO1Fc5P0eaio7Wjaxwy5ChdzIcRYd5S7lYhANUHxZD9qVyrvoaIJSbH7QcK42-86t=w702-h936-no?authuser=0)
Then I drove 4 small brad nails through each of the holes applying a liberal amount of Loctite 603 (the thin retaining compound) to each hole before I drove the nails in place. I went through and selected the brad nails to be a very light interference fit in each hole. Each of the brads went into place fairly easily with just a couple of taps from a small ball peen hammer.
(https://lh3.googleusercontent.com/pw/AM-JKLW3I2oSlg-5vVeIpGxcIUuwH8NPRyI2P7Qx7V2xs9-a52ZxvDaSNUlPo6kwhkem_w3KWeMqsuEv4wZ7Ra9Oa6-5DXJk2NDX0HbHcAARM3HXT4L2-w2YykMqunSsh2kiBL8efYu6XfnYIcuvOduqb4dq=w702-h936-no?authuser=0)
The next day I clipped off the excess length of the protruding brad nails and ground the remaining bits flat on my belt sander. The back to the mill to remove the section of the crankshaft to make it into an actual crankshaft.
(https://lh3.googleusercontent.com/pw/AM-JKLVxMFEgk_SnhsgkgD_ZNEcRqFQghSwwFTzhCpVLsw93xRyKAfUXZnoh1WBZMfMvDjbzOLhOQOZQas_QkPapmqHbR4kHBmWg0QvWYJcnKPhMIDUSuzxEnzKvnmat_1OKFCtIIb4d1WtynMNkiodUYLVk=w702-h936-no?authuser=0)
And finally the finished crankshaft laid on the print. The brads used to pin the crankshaft are barely noticeable.
First view.
(https://lh3.googleusercontent.com/pw/AM-JKLVIsEiH9Q7KhS1HEliBEOy7XDtUA0sVbp5_3HBGotlfTeXeOZMUckqInJWM-KlzNh2-WWMBgO-b46bQXQVnWSQrROJW3D_Zi4_X0Bzb_gO5g_6qzwxLChI1BAGM8fI1_zyAC6fEqtbuMdJpNJE2bhWZ=w702-h936-no?authuser=0)
Second view.
(https://lh3.googleusercontent.com/pw/AM-JKLUtvNwVROwd3l8BQOCPdcjOr0bC3de2D9usA7TH8VYL5dA1LKVH_YypC_L0_mG8yEIf_aYc8gVtWH6PZ7gsldBs81zj9II2zIh13LR1gkLqi-R1T9qLz_OCaYHyL-_EOYvVbkTUGlkJeJVOi3Q7CnuR=w702-h936-no?authuser=0)
And that completes the crankshaft! Hopefully it will hold together when the engine runs. I'm hopeful, but who knows??
Enjoy!
Mike
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Looks great, Mike. I have no doubt at all that that crank will hold together! :ThumbsUp:
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Looks great, Mike. I have no doubt at all that that crank will hold together! :ThumbsUp:
Hopefully it will. If it doesn't I'll build a replacement from a single piece of stock like you did. Base on what I've read from Brian Rupnow and others, I'd get a piece of 1144 Stressproof for the stock.
Good luck on your build!
Mike
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I'm going to make several posts, each on a separate small part that I've made for the engine. Hopefully they'll be easier to read and follow by breaking them up this way.
First up is the cam shaft / hit-n-miss lever mount. I didn't show the operations, but here's the pix after the first stage of work on the lathe. I took a piece of .3125" drill rod and turned one end down to .25" as per the print and then drilled and tapped a 4-40 hole in the end to mount on the frame.
(https://lh3.googleusercontent.com/pw/AM-JKLWCZl9sJx9D2AwpBF1jACBzAQLBF63XE0FqKHwsxnTYyPhFcvmAge9QajYiSDlYrqaODKsiBAR3gHbJrTjmU8lREPIyymialuKMRMxS2QvQ1OAT_GWuV50LCDw0Q415HZesdDu41YVPmnKun9Q5ljV7=w702-h936-no?authuser=0)
To cut the groove in the shaft, I mounted it in a collet block by the .25" end and then used a 3/32" saw to cut the groove. This went very well, certainly much more easy than attempting to use a small end mill to do this job. I also made sure to use my mql setup to lube the cutter and blow out the chips.
(https://lh3.googleusercontent.com/pw/AM-JKLWowUjOFZrv9LxzOJTCULKdZ9FXRcREoAJE-VQPdSVMGSKqSYQYrCDZRyCOxE_gwcjWAXzoWdqluW57rwdRmv7q1IqiHmExfNQCzg5B7t7E0ZX8_LMEYizsUYxAT96hfvCaMUyR05kZw6CvbPM_a3qi=w702-h936-no?authuser=0)
I decided to use shoulder screws for the various pivot points on this engine. So for this shaft, I drilled thru both sides of the slot with a drilled sized to tap 2-56. Then I drilled a clearance hole thru the top side of the slot, then tapped the bottom half size 2-56 for the shoulder screw. I used a spiral point tap since this was a thru hole and I find the spiral point taps to cut much easier than a standard plug tap.
(https://lh3.googleusercontent.com/pw/AM-JKLU4CWmYuV0Zh6KH3hVaO5W2ngDMyAoconUjEcRIc53pyxhITsLGJccXUGa1sBb6C-RJWksLQE5xpqwniWc-8KTgve8iBtgM81gpoWGxxixQJvRz82zrGyX_5axiAvjlGywTfIr-b4DpUtjVtDfsHKWv=w702-h936-no?authuser=0)
And here's the finished shaft on the print. Note that I also milled the top of the shaft flat so that the shoulder screw fits correctly.
(https://lh3.googleusercontent.com/pw/AM-JKLUakrlMidbOmn9bhQDFgN7zTQHH3NDi2YoAqIRl7mZcHb1s2N7l0-PdMsDFJbgDETrZtenbjhM1cfiLU9tLm6-u8pS9h__ePpdJWXGJh083Ia1FKRWbhDRipH73WR18aT0KXRa9uEioTVL_OS005ISM=w702-h936-no?authuser=0)
And that's it for this part. I'll post a couple of more parts here shortly.
Enjoy!
MIke
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This post will cover making the valve push rod and is quite short as it's one of the more simple parts.
I cut a piece of 3/32' drill rod to length as per the drawing, and used a die to make 3-48 threads using my home-made tail stock die holder. Shown is just after cutting the threads. For this sort of small thread, I just rotated the die holder by hand. I did apply a bit of EP-Extreme Tap Magic prior to threading.
(https://lh3.googleusercontent.com/pw/AM-JKLUPH2f43Z318sS24MSTGDtTwBGABusXt2XREzSmtdPNCtEOH-I4UiHgXyDZ-qgX8M1Chj61o1moFHBsVExbxv3eCJchPSparWBkdMM7IpJ-D14_4vc7CyvaNCNSrel6ARZNsVcj_2wpyvsnSvWWAKX9=w702-h936-no?authuser=0)
Here's a better pix of my die holder. All home made. One end holds 1" dies and the other end holds 13/16" dies. This is one of the more useful tools I've made for making parts for these small model engines.
(https://lh3.googleusercontent.com/pw/AM-JKLVBHXyC-tjGNn34VOz7AFv69SBsk1_xJNMWxGoe38rqDlUDymtmEYfMo-VB9D7qsE2hR0vdZyAyIH9FD8KtI1WoKSQj2kIuxXwm6cT5b5J6bqLr5T9HE_XUad1oPccr4MBBKHKpioyyef6aXkfsGkuT=w702-h936-no?authuser=0)
And here's the finished valve rod laid on top of the print.
(https://lh3.googleusercontent.com/pw/AM-JKLXBPpDeL4ShlfzdoOF-yS9CwvgPuXfgzvJ5dnfh4f_gMm5wU4UIBVxk8w2wFHjgKVEI3BTkWaI0h1GMiy5PbmRzPlHfm9PwF7zz8SioC2PVavOMAA5MwLLOpVlDlYwZqbCq6_QMQ8QVjJXCUJAI64qh=w1248-h936-no?authuser=0)
That's it for this simple part!
Enjoy!
MIke
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This post will go over the gear assemblies and cam. Note that I use the word 'gear assembly' as I actually purchased the gears and then made hubs and assembled them along with the cam.
I must hang my head in shame as I've not yet cut any gears myself. I intend to one of these days, but I need to purchase some gear cutters and am wading through the choices there, and I bought a kit to automate my rotary table and I've not build and install that bit of gear. I'm thinking about purchasing some import module vs diametrical pitch cutters just due to the price difference between the two. I think I'll probably eventually purchase some module .8 (roughly equivalent to 32dp) 20PA. If anyone has any good advice for what's best, I'm all ears! But I sort of have the excuse that purchasing gears for a few engines is actually cheaper than buying cutters!
So for this engine, I purchased 2 gears from PIC Design, models J23-20 and J23-40. These are 1/8" face width, 32DP, 20PA one 20 tooth and the other 40 tooth. These are both unhardened 303 stainless, hubless with a .375" hole. These are exactly the same pitch diameter as the 48t gears originally spec'd on Upshur's plans.
For the crankshaft gear, I made a steel hub since it will be held to the crankshaft with a setscrew. Here's the first pix. I'd already turned the ODs, the smaller bit to fit within the gear and the larger OD to allow enough meat for a set screw. Shown is tapping the 4-40 hole for the set screw.
(https://lh3.googleusercontent.com/pw/AM-JKLVoEKUQObsI_p-2l3hhozYGnmPxQTU_cs8mDMpmt5d_jtpvX9AIDgozLNhdbCC3JNiBxUsoI6CVErAEdsHOYC_JF_j9FtxYy465TuL02ZBvBxnv2R7epbCwu1eef3-06TnHKOiPj0HkpwsI6oz_7K14=w702-h936-no?authuser=0)
Here's the gear and the hub I made for it.
(https://lh3.googleusercontent.com/pw/AM-JKLUPn8QnY13qe7MHde7WD-vO5kCK__lWq9sd_8h7CPpuvfCylrJAQL1WPF9WZkzuJujmJPONpR9B6FeTvdOWtGy1CV5von9lkBMKF37I0iOuV4OJLFYv7YSfD4OIGHwF7E8ivGdrzaP8RFvX4WL-iWl3=w702-h936-no?authuser=0)
Here's the gear on the print after pressing the hub into the gear with a little Loctite 638 applied before being pressed together.
(https://lh3.googleusercontent.com/pw/AM-JKLXn1DqBufF1b8p5tk1YzbKOF24Z5-Bl7SP8enTPVNWVuvc9Q43bjDuF1JUSiqck1jDnJo7u9T-qYK0PoeOa3AA8zeyQn5Np-ANG8xK2ENeOqTD_If05ERkKyH0_yVKPVgHF99lsjVjBYeKilOeX4PBe=w702-h936-no?authuser=0)
And finally this gear being test fit to the crankshaft. One of the reasons I built the gear this way vs what Upshur calls for, is that this makes the exhaust timing super easy and easy to adjust as needed vs the fixed arrangement method.
(https://lh3.googleusercontent.com/pw/AM-JKLXQFoji6VkfHmbmSOdN79GslHtddAzlGdGflwydoUL3gPI-305sx4RWFLbByAzxGFQ8Xd1xs5vPXkKu9Vl3f7knUWTqJesuJEqqx_mCPDOKb2bnDp7cxEOW8yqzbbEecgIGcA3hO6Cce3VODC-s-1uM=w702-h936-no?authuser=0)
Next up is the cam gear and cam. Luckily, when I built my Webster engine, I cut the cam stock long enough to make an extra cam. Originally I did this in case I needed to change something on the Webster. But it turns out that the Upshur cam design is exactly the same as the Webster, so all I had to do was to part off another piece of the cam previously made. That's what's shown in the pix. That's my favorite 2mm carbide parting tool in action!
(https://lh3.googleusercontent.com/pw/AM-JKLWx3_8F1UjhzLZFhBa38XITSyO7BsxwbbVVoaZN90FhZhYdM_Nv3cFfJCys5sPYOawA34MR4N83_WxQwKmlRb0CxVuA9ERg44iYBr3nVr8HhTG_KDQmruJhE2khUGPjJfhJhGTfcEvOACL0Bsoven0y=w702-h936-no?authuser=0)
And the cam after parting off and cleaning up on a Scotch Brite wheel. It came out well.
(https://lh3.googleusercontent.com/pw/AM-JKLWWEDD7UZIGrHthrmWQszH38SyqUHjWWCDPxQARxlXtD8uGWOZ4oTaUB_KrCt1LahoJvhKGfO5ixlbNslawjFR-kRmEx3ZYiemtoe0SIWccd9cOYXCsi8XYutgnORShWCS_pENHbRUWAUz4uXEAmG4q=w1248-h936-no?authuser=0)
And here are the 3 parts necessary to assemble the cam gear and cam. I made a small combination hub out of SAE 660 bearing bronze, one end .375" and the other .437". The reason for using bearing bronze and using this method, is that the gear and cam have to rotate on the camshaft so it's way better to use bearing bronze for this application vs steel on steel.
(https://lh3.googleusercontent.com/pw/AM-JKLVULApx5VXSHFKIcNONegjJofessbS8kdkZgMrv0g1hJtIKOZUSy_ap_Lp07B5GXIWrfgL2CRCoPoTMlZ2-uegjBHZ24LqpM7w-GSSf0WpXYBuSVS5UJBpkyJ0npUxK2PWBvdOuxJvKfYaAyVOAc7cK=w1248-h936-no?authuser=0)
And here's the assembled cam, cam gear, and hub. The pieces were pressed together using some Loctite 638.
(https://lh3.googleusercontent.com/pw/AM-JKLVy9vRnMx25G6Dprf-J-bteVY2NiPieyLkwje9kiCY83dpPDUOvaE-2VQ666-gPbJdjSC9Xy_ECKievJ7yp4sRQONkBRKLtoa74Ch1tM3YEwQo_DNnYckZfvl52SmGKa2VXGKdR1Hf86UOsQFbP20bP=w702-h936-no?authuser=0)
And here's a bit of a family photo of both gears along with the crankshaft bearing carriers with the bearings installed.
(https://lh3.googleusercontent.com/pw/AM-JKLVltU6Z7gmZufAwpAzZ7mn2Nd576s0xT1Swmvutd1FV8wufPKHY1Ho4YORHyoZqD2LZM9dJtS-bORo9Qzw-OYqPIVOl96caAED7aB3CHZr2JrjruX1Qk0hW2--SAVshyXrtgnK5CZEjA9C9PmljEmaD=w702-h936-no?authuser=0)
And that's it for the gears.
Enjoy!
Mike
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For my last part for today, I'll show how I made the hit-n-miss spool. This is definitely different than Upshur's design in that it has 2 sections to separately guide the weight arms and the activation lever. The challenge here is that this is wider than Upshur's design so I carefully modeled all this in CAD and increased the left side of the crankshaft enough to accomodate this part. Just as a warning, this causes other subtle changes so don't follow my path unless you're willing to carefully model this all out.
I started with a piece of SAE 660 bearing bronze that as you can see, is quite beat up, but luckily it's quite a bit oversize so I could easily turn the OD to the required diameter.
(https://lh3.googleusercontent.com/pw/AM-JKLXLMRdZgxsu0BPQWxrB-sbMkyHFaW4hVQTZjqWp2ODrtBac15Z3nEyKWYkA3sbSLS5HDPnPT1pUQp0BR1ult6lHQ8M-Aq3wdkZsvDc2S5axJ_me4cTTeTRkNpZw9tmT_4DLSyHcvUE0oRsw11mMBVwa=w1248-h936-no?authuser=0)
I turned the OD with a standard CCGT insert tool and then cut the groove using a 2mm carbide part/groove/turn tool. I also drilled and reamed the ID .001" over so it would easily slide on the crankshaft. The pix shows the start of the parting off operation.
(https://lh3.googleusercontent.com/pw/AM-JKLV23LFAKDfTy6jOlUzMMJb_RBm_flPThmRhNzBv63V59ncA7Nbnl3dFHw9iwmwCy4YKwO9uGptxrQdWpjBFg52GzqVeEUBB2vLXvf2OIVKfi-RS9Uy00aZnrpAydF3PbkNlnWk4KI7Sj3H5nZSAGAyu=w702-h936-no?authuser=0)
Here's the finished part on the print. The print shows my almost illegible scribbling giving the DRO readings for the various features. I normally try to dimension the drawings using ordinate dimensions so I can directly use them with my DRO, but for whatever reason I didn't do that for this item.
(https://lh3.googleusercontent.com/pw/AM-JKLXZkPh9UoAFbzfsJ60V4kqZ1aBgG-vqRRaWqE0znxJeWK9sEHlMlvV9kH7KwiuD2qk8Lp3T82zEQcKTxs9DrkFCKG7z-bwTEXbfPhWSX3hato6g9z7JK82ypG7ZNV1f3OWtrbshn9YUcqB2EndP1K9l=w1248-h936-no?authuser=0)
And finally the finished hit-n-miss spool fitting to the crankshaft.
(https://lh3.googleusercontent.com/pw/AM-JKLX_M6yeEW1dp2g0Smb2Ud8_gfwQlyF4OA1FNuW_UOi8XSI9R2sMd14syiXDOVrzd5ifiaBnMgs54WZxSLGotG-pe-lV2WtGCIeQIGg10_BCERDnVKtDjcM-jfvT08L0YPYt4JtXkOQt5HjQldUOHsxj=w1248-h936-no?authuser=0)
That's it for today!
Enjoy!
Mike
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That's a lot of nice little parts, Mike! :popcorn:
Kim
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Here's the build log for a few more small parts.
First up is the clevis for the valve rod end that will attach to the rocker arm. I started by cutting off a piece of 1/4" square stock a bit long and placing it in the mill vise, making sure it was vertical.
(https://lh3.googleusercontent.com/pw/AM-JKLWdaw1XpLlHpJ57vvoziwUL9dIBG8Lq0PRHh2xJELOCWlXC-e7N737vkEKzbf-KKBxhVIOS52nSpD7-Pd7TfhThhoL1o8P2ltwXRy0S_iZQGnJg8UQqtXSvGSqM3jWvtvGpQFpLKfyAsQEYcOi9zJRV=w702-h936-no?authuser=0)
Then milling the slot in the end stock to start forming the clevis. I'm using a 2 flute HSS end mill turning about as fast as my mill can go.
(https://lh3.googleusercontent.com/pw/AM-JKLVImOQxgrA0Tu54pOhDnFHuWmTFEU5O3lZxeUv9MH7rKeZ1QObaKea0VvB7FPg5Rc5hQqgsOi1fOq4XCeUgs8oN2WGoZr_mbPASCCTarVxRMU3-lcufr1HRhdFifhHAYLWQVV9wT2uXKsEjVoun8rel=w702-h936-no?authuser=0)
Then I drilled thru both sides for tapping one size 2-56 and then drilling a clearance size hole on the other side. Shown is tapping the bottom side hole. I just placed the mill spindle in neutral and rotated the chuck by hand. This works quite well for thru holes.
(https://lh3.googleusercontent.com/pw/AM-JKLWsngd51PdgdtcDGmROW8mOZwWKjCBqzFUiw-mWlYtJDZvV4-WRDcBpP82ssGAqgnUo5ljyXU7sX5Pggo-1m7E1fbAdudkB-62JfSHOYd4dxe_wwVdGmqScTJlsLxkFYYqzKU1sFLmfFWVwreMaa-ep=w702-h936-no?authuser=0)
For rounding the end, I blued the part and marked the radius with a gage and a sharp scriber.
(https://lh3.googleusercontent.com/pw/AM-JKLWT9BFC82Xe1INi-0xEmHqDiFclgkGo4VtQc2Fj-oJRnHUSNB4KskWxO7Ekd_zV0hp59G6zlNdur-Vkw1ImRhiAdwe7W537vhxDYZNtZNeobEfhxqb_f1r-SYvhY0KOL7Jcwap_OnOsERJTTfAuCWZg=w702-h936-no?authuser=0)
Here's the marked part ready for the belt grinder.
(https://lh3.googleusercontent.com/pw/AM-JKLWycykTKBjZjRHtSXRHw93Aq75eDithTaWNx2NVHfv5c5mkj3muVmVYPD4-tofQZAqA7-Ma6khHeEVE8lC6cF4ZL1mhp23ELfJFFH1R0iiytiEx3sQFaPAGAJlDKFFiPdNwfjGy4WMin5b-T_7IznzJ=w702-h936-no?authuser=0)
And here you can see the part about to have the end rounded on the belt grinder. You can see why I left the part long as I needed something to grip while doing the rounding operation.
(https://lh3.googleusercontent.com/pw/AM-JKLUaHClHDBqVXntWJRyC3e3UIHwVyNYWctytH76Szfrb1J2qItO4xnbidQklEWWtuhgLl5sCgRZVoeRCIvEQCLqe59fCxaSK9VZZegyjXlp2849tZKUjuNmPcCnORDDrxd6QBMXxwzDuDYFO0CoWGQp-=w702-h936-no?authuser=0)
Here's the part mounted in the lathe in a square 5C collet. I parted it off to length and then drilled and tapped 3-48 as per the drawing. That's a spring loaded tap follower mounted a tailstock chuck along with a very small tap handle. I find that this combo gives a very good feel when tapping small sizes.
(https://lh3.googleusercontent.com/pw/AM-JKLWZMWrHFaBioKjIFuxmT_bCFijXGvXWyX4kib9rq1uhRgaVvcINP2qfaNxRiJeu3xxGWQyQShcKq4wofsN8956o6yjXHI5jTeYXa1rAcS6PJf8JWF4MdkplO8Ko_RzhnUB96DBZ85Cti4A6vduxiucf=w702-h936-no?authuser=0)
Here's the finished part on the print.
(https://lh3.googleusercontent.com/pw/AM-JKLWq3lhhHX6YWtf6AaRWx6uTD3wYRzf422z-D99b0TiIapajBmVLQAo-15cb6Yrw4JJUWPh58oxK_SSE_hYg_a9nYXZCTIkD3H9ZsFpRyJgUbbvSLdmkFEFreNe47XjPeTjul0vOaqqcbgUDZKI4Oo3h=w702-h936-no?authuser=0)
And last up for this part. It's mounted on the valve rod and I've installed the 2-56 threaded shoulder screw and luckily everything fits!
(https://lh3.googleusercontent.com/pw/AM-JKLXeFa3RJmozOQRnOIWQintlpn-FK5GdFKCwEa5irvARNOdLJ1Z2ZLooJaU7snrttqSzHiyE8V3IAGSqmYlLEBbRdpNsjMXoebnolHIHf8LQIu-OCAK0v3chHKeAEQZtdmrITcmVfZJW1TnNkTAFYWXF=w1248-h936-no?authuser=0)
And now onto the exhaust pipe. This is a very simple part so I don't show any of the operations to make it. Essentially it's just a piece of .25" brass stock, cut to length, threaded 1/4-32 for .25" on one end and drilled thru. I decided to thread this part since the I noticed that on my Webster engine, the exhaust pipe tended to loosen when only secured with Loctite.
(https://lh3.googleusercontent.com/pw/AM-JKLU7AyzpW4obp6sFVqpek25dgTzqIXV4_zGPDaCJA_tDsk4o9Lz79HnlsuSuZcq246n7fd89FMm6m1GBYwr09pJDlFS_5vd9VqNh0USMHF92taBvKJq1edfrBGe-0W_lWULnWFdkO5GmL6aNLBFka7wk=w702-h936-no?authuser=0)
Next up is the rocker arm post. I didn't show the turning operation but it's just a piece of .25" drill rod with the end of turned to .187" OD. Shown here is milling off 1/2 the thickness of the .25" end. I'm holding the work in a collet block as I find it very easy and handy for small parts.
(https://lh3.googleusercontent.com/pw/AM-JKLW9C0RUIOZa9wN7pJy3dkGbBN2BGwFe86BIyYLfMK0vS_KV3Tg5Owk8vtJr3V0ycIub1N13dIHJOcL0RC-Jz1GGkDlXmkFdAv82Zfg2Qyim1z0f4K68zbmQrC131Ht18K8_P3L3q-eK108uodsQHZuE=w702-h936-no?authuser=0)
I didn't show the operation, but I drilled and tapped a 2-56 hole in the center of the flat. Here's the finished part laid on the part.
(https://lh3.googleusercontent.com/pw/AM-JKLXrDcyC-7lE-JPJ995LaaRVW2Nzi4n0Qs9qR6edZ4arjeTotoNP2trPeJepe316G1x1zqO3eimswlNCrrZJwVFIm4awArfV5Yaw1qXDGYCpR8x4eqFDPtNo3yjuNKI_5Ug6VWJVWcA30qT4THDCP2Yd=w702-h936-no?authuser=0)
And here's the rocker post test fitting into the head.
(https://lh3.googleusercontent.com/pw/AM-JKLUArf4vRYn_1F4Ej5xGpH3VoB-yHfq6HBewy98TNXuBlVfZNx5jvpt6PGa5jpSMhWN9YMK9AfKqkWV3K0YC5TFk-puaipkH-sbSmrhhJ6yVHffT4JTY3a7v6Cvu-hgypjYRPnJzjI0sSOFmV5uya88O=w702-h936-no?authuser=0)
And here's a tip for any future builders. The original Upshur prints show a .1875" drilled and reamed hole all the way thru the head. I'd recommend NOT drilling thru the head and shortening the rocker post by an equivalent amount. This prevents a potential leak point.
And one last part for today. These are the valve guides. I didn't show any of the operations making them as it was pretty much all simple turning, drilling, and reaming. I made these from a small piece of aluminum bronze that I had on hand. I did change these from Upshur's original design in one aspect. I added a 2.5" degree taper to the end of the guides. This helps eliminate spring binding and IMO this is important as the springs are quite short and they may get excessively stiff due to lack of travel if the ends bind on the guides. This taper prevents this.
(https://lh3.googleusercontent.com/pw/AM-JKLUWFJIA2M7l8xkatK4lH50siMHI0p3Xr9NvIp8zKM087ekbZGguVWDlLsWHrLtE2_AJKmzXWyEwskqmChWR8BN0PwBp3iahtMx1n4r6DxaLZqggHV6o4H26hRFFgV4VgsuxJJ3Oy_dhN59Ogqfts6ii=w702-h936-no?authuser=0)
So that should do it for today.
Enjoy!
Mike
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You have been busy with small parts - something many here take a lot longer to finish :ThumbsUp:
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Today's post will cover a few more small parts that I've just finished.
First is a pix of everything I've made so far assembled to check fit. A minor miracle has occurred and everything fits and turns. There's no piston or con rod at this point so what I'm checking here is the fitment of the cylinder and head to the frame and the gears and cam.
(https://lh3.googleusercontent.com/pw/AM-JKLX4498GakFOgvgNQm9Ak63DD6Am5eRw63vrMWRIYv_AP-h5-9NcydkSOFc6LkaJATbBUSvSZ8w36hYTxrb-jHDzvC1RWjD4ydLWBteAFnEQ4xXIYQraMataWN3i4_ytd2MYTBd6IjZ8Jb4J1cEFeBXv=w1243-h932-no?authuser=0)
Next I'll show how I made the rocker arm. I started with a piece of steel I had on hand, and brought it to the general length and width of the rocker arm. Notice that I've left it long. I'm showing drilling the two holes in the to be rocker arm, the center for the pivot point and the one on the end for the clevis attachment.
(https://lh3.googleusercontent.com/pw/AM-JKLX-PVs7rdxwHJbRwqhMhp3duRuA2qLaKzJg9trxmmg4bbH1mv2Hkr2G3U9ZvckzkjQfzE2EppxfxEuqg7_TLgSlH0eCfxEis6rDhExZLJt_xeaheu-AVa4D2DTHVPlWAPRv0MkIHj8uWuuFJX75Q0Ib=w699-h932-no?authuser=0)
Next I used an end mill to form the radii at each of two points as per the print. I located the points using the DRO and then moved in y axis until I reached the depth as per the drawing.
(https://lh3.googleusercontent.com/pw/AM-JKLVUWZ6bx7LgVXcX9v4o2RsN7LcijIO3GEXmn3Vo2MIps-3CisiWvl7jf75Ju6jZqHhGF4hQesmwaL2PIierg3MuePRNwZFDXJx85piqyhWm9SFaYYreSP1RvZ6dKg6vqPIozJ5AngQghE4TlXeHPj6F=w699-h932-no?authuser=0)
This is how the work looks at this point in the operation when viewed from the backside of the mill. I think this shows more clearly what's going on to this point.
(https://lh3.googleusercontent.com/pw/AM-JKLXaMNjtYFMoCXhYjE8_BmOwpK6UvguUJ3AWHp_HvIUIyJkn_Hk5VFfLEamx0jaJMhdPUlkjRfMIIULbKWS2rSBr7C3b6BKAOOAlkXuMTPLu7YoVAzGMLYbj72dkqoUdtPgDPjUEWSRemX5ZlcPl1csV=w699-h932-no?authuser=0)
Then I used a slitting saw to cut off the part to the required thickness, I think it was .094" . As usual, I'm always amazed at what a great finish a slitting saw produces. You can probably see where I"m going with this...............
(https://lh3.googleusercontent.com/pw/AM-JKLVdfMsxwf-F1VDUzqsyh3aYdDYd2DaeWM3A7dsXL0kNLJvLcjM__saF5emQ6W7WNbegX0kJSEmDqzAweZMytbv-tgrilvCUqsnLmp5xb9fSkMnKk0y054bEULfbTl7bZFy5eYdXzRd8iJEUHgKB_o6P=w699-h932-no?authuser=0)
The part on the print after I cut if off the base stock.
(https://lh3.googleusercontent.com/pw/AM-JKLUc0mlgw8LkSj4rkpQg0a-axEJHAI7IoHNPrOkSVyzHz6di3aXkJwtUA3odvaHhflA0tODw0HBO74Md2g4o9XHadf_o2pETDnTBsEvBxvZSPXWfcP63a990Gp3ebUdP_s-0Jq8IazOqlopSdICQbgLj=w699-h932-no?authuser=0)
And finally the finished rocker arm after I rounded the ends on the belt sander and on a Scotch Brite wheel. I'd blued and marked the area to be rounded with a radius gage. I think the rocker arm came out pretty good and making it the way I did nicely solved the problem of how to grip a small part.
(https://lh3.googleusercontent.com/pw/AM-JKLV9Jah1OvxwRbfe4nFPlyAnr8egoYH3DSG-8bh4ybNVLUpsoqn8PUt2VU48Ee00UKH-tlRsSB8UJFvrBVOAKNvkvnzRNvdfppChLG-6dFbkoqLSrlNgVS2ePCi17swBuHEIFtKHg1aWY76uR1EK0HmW=w699-h932-no?authuser=0)
And here's the rocker arm, clevis, post, and valve rod all assembled.
(https://lh3.googleusercontent.com/pw/AM-JKLWHZ30XM2UT-oNg5IcJtW0ihHfkASNaxFq1F1q0KK6zxx3LD0ZjFzIKfB0Ze_hSqdZNPfLChd4podDHHyDR_Yc7dLG8fIwW8lPpL8_i5fD6BXxNzClL6gcnsornTkJdjJQfgp4SoNHaWSr2vLmiz_ei=w699-h932-no?authuser=0)
With the rocker arm done, I started on the hit-n-miss lockout lever. I ended up using pretty well the same technique as I did for the rocker arm, so here goes.
I cut out a piece of steel and brought to the overall dimensions using the mill and you'll note a hole drilled from the end which becomes the pivot point in the finished part. I didn't show milling the stock to dimension or drilling the hole. What's shown here is milling away the material from one side of the stock to form the 'catch' bit of the lever.
(https://lh3.googleusercontent.com/pw/AM-JKLXFHvK7YPtZL0CVabYcsYcYbXWL9JTA_1MgoHikTqLk_aZ1UKiGmlNKVz-nVYDL7ukZynYY6YnUiHp7jGoVyQ3szLs8yIj8gDhRDqo4-AxhWA1fts80ryrNlcLfB77nuFBMJS912klqsTVaQK5IxrTR=w699-h932-no?authuser=0)
There's a flat area at one of the lever so what's shown is milling that area to depth.
(https://lh3.googleusercontent.com/pw/AM-JKLWsVFtF9AQshK4n_gYD4F1vryt1CirPg2nmqxRBsjAlepQbH5zExLh5bKm9ALGcnTud-TWL9wL7jJ9QO2YBobH_lSlhIjbuP5Ja429RZPREqNHaZOD6AA0KceVHLni8Cm_3aPFSj6CnpfxmtAjZ9uXm=w699-h932-no?authuser=0)
The remaining portion of that side of the lever needs to milled at a 15 degree angle. Shown is a 10 degree plus 5 degree angle block set on top of the work and indicated to be level with a DTI. This assures that the material will be milled away to the 15 degree angle. This angle isn't terribly critical so it wasn't probably necessary to get this accurate.
(https://lh3.googleusercontent.com/pw/AM-JKLUl4J7Mjhoo2SCJHjdPklRI7Pn57dd2YBBYXqHLUjfgTFhJckSPT7Aic2mx15mjKBRHz-29uw5DfbtDHPGTO3RwLVaD-0LHn9_RWDOu72mOhDModNVqDb2TGkAWfnGMCgxbUWwkBopWHzz0oWMJWHoD=w699-h932-no?authuser=0)
And here's the part on the print with the work so far. I did it this way as holding a small thin part like this would otherwise be difficult.
(https://lh3.googleusercontent.com/pw/AM-JKLUS4pmaowEdI-LJXO8-uqex5yM1c2caX24rn8wxnq3QZnrb2Erd5lyMUrSHcucg8CjWhQq8C1uDl5Qt5Je_MQEQ5p2iHcMCPWrKjHJIngsyBa1DTsW8UX-fl7KH8DYKzoOATa1jfV69VjoR8xTTfCq7=w699-h932-no?authuser=0)
And then back into the mill vise, the flat side against the fixed jaw and a liberal amount of Al packing to secure the part against the moveable jaw. I'm using a slitting saw to part off the lever to .094" thickness.
(https://lh3.googleusercontent.com/pw/AM-JKLWi5bUWYMGFgGRI0nL7h74jwuAa1ZQPMiIRtqbe3wLXfYUF5VMXXJtDJBQ-LXr_zuncZzyVfknVVDa4dJgCR3Ln9iz6sXeqGWwKEZLFcPmceRkVVCq_8HdxE1LJde8qkhc99_MeyYNB6D6vevzgXm3Y=w699-h932-no?authuser=0)
The finished lever after rounding off the end with the belt sander. The tip shape will be refined whenever I actually try to make the hit-n-miss mechanism work.
(https://lh3.googleusercontent.com/pw/AM-JKLVnNVMPGhl14adoYmcOq_xV-z_jZj-hdfpJrNRqxA3s_joHdqncZ_8OgX-IjZASD4tkr6dK7ScRID_dNNEOgroCQ3uK2r8bcVgKN7g29iFJv6Oy3J82v9wnEpmUuMDZ7vBTYj9hlqzqYllsluJS0Xzv=w1243-h932-no?authuser=0)
And lastly for the lever, a pix of it installed on the engine. Certainly it fits, but that's no guarantee that it will actually work. That bridge will be crossed later, hopefully successfully.
(https://lh3.googleusercontent.com/pw/AM-JKLXTcZfhfPhp-6uHvklMDDb4ssMnMgdsY_0t_uaCLHdwPyUpgT13SitnIqnnDu3V9vcon18MUxzAqYHYOzj8SPWAjWLkX-adduCSiJI7Hrk5cwQNog35Y7kBud2xAgVLR4nOLNfju7HsYRClgLRFM7lS=w699-h932-no?authuser=0)
And lastly for today's posts will be the piston and wrist pin.
The wrist pin is just a piece of drill rod cut to length with the ends rounded.
(https://lh3.googleusercontent.com/pw/AM-JKLVf7yJC8NckU4Z-HsSmzq7-4joDYTsDbbnww0OkYa27n9-p-NryNGt8JBzfnlUB_QasrpZuJsaptT7IkkmMYK-XVaIlXm9Si_lQ19SS6DYnsT1UjlDpaVzmmOxaGwroI6HKZTKo3CpNxcZZIphoMmXH=w699-h932-no?authuser=0)
I made a corner rounding tool some time back as shown here. It's a bit rough, but it works. After I cut the rounded profile, I filed it a bit and then used some emery cloth on it and finally finished it with some maroon Scotch Brite.
(https://lh3.googleusercontent.com/pw/AM-JKLWiSQNAUeEnr-qekSr-berNPTyV-fbfGnRS0-1ODN3ICVwpT3naXWNSh4VCoCC_BeA7NTz1HkqbrWWaYfKWkA-gv3Mgb6ebKhkOcFqXlmyiabhPEjv1oj3ABKbEwMz8kV5nXUWdsPAo7FIPFqvzpU5Z=w1243-h932-no?authuser=0)
Next is the piston. I didn't show any of the operations as this is a very simple design. Everything was done on the lathe, except for the wrist pin hole. I did that on the mill holding the piston with a collet block and drilling and reaming thru .001" undersize. I did want to point out the dimensional details for the o-ring groove. I use the method espoused by Bob Nawa which calls for a minimal radial compression on the o-ring only .004 to .005" If you look at the attached pix, you can see my drawing notes on how to form the groove. I used a 1/16" x 3/4" OD nominal Viton o-ring and based on my finished cylinder ID of .7505" the o-ring groove depth and OD is calculated. When I cut the groove, I used my 2mm carbide grooving/parting tool and carefully progressed it while carefully measuring the groove diameter. I was happy to land right on the spec'd OD at the end.
(https://lh3.googleusercontent.com/pw/AM-JKLWZO4OvXMhg3nuFgytQg-2YDnxUJqDLf9SQsne-9Np6UBqYU3tXK6bQvkIxXq0sEkIFsttgmysR8YoyCzt_LrGMp_lFTV0lPVXBB0vSpLb2HxbKIOoaBObJXp85N6XQm99WjW9hFRjjPykHbB-_Jx5a=w699-h932-no?authuser=0)
And finally the piston is shown fitted into the cylinder. It fits well, being a nice slip fit. It's actually .002" under the cylinder ID which is exactly what Upshur spec'd on his original prints. I went with the Al for the cylinder since that's what Upshur specified, but I personally like cast iron for pistons better as I think they can be fit a bit closer with very little tendency to gall.
(https://lh3.googleusercontent.com/pw/AM-JKLXOKPee3kt455wHDNlFh83y4S05_DEiWUMiCdTVZL4GMXQm_2z9n9PiAl_gxqBvUXf5P89P_8B1Tv4KbSgvdHvRbSC8Xd_eWC951hbLwk7-pwzbyFtwDjbTExzQPOs8srpWUGgJ5p0fezX9_1h2ejXQ=w699-h932-no?authuser=0)
And that's it for today!
Enjoy!
Mike
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Lookin' good, Mike. You're making rapid progress! :ThumbsUp:
I'm not building mine as a hit & miss, so I get to skip that lever,
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This post will go over making the connecting rod. I modified this extensively from Upshur's original plans, mostly because I wanted to, but also because I thought some aspects of the original design wouldn't stand up well over time. Unfortunately the side effects of my modifications were added complication and added time to build it. But in any case, here goes!
I started with a piece of 5/16" thick Al and after squaring it up and bringing it to the spec'd dimensions, I drilled and tapped w holes for the ron rod cap bolts, the top portion being drilled out clearance size for 4-40. I also drilled a small center hole in what will shortly become the rod cap.
(https://lh3.googleusercontent.com/pw/AM-JKLWQAx4xEc3EAYLJsyzobkc0Y8PY4bVyNFjY0CvZEw0mXiZ6Qcv__9_WDZYPzbmSRMGoh2fZttvo-sghwJti0OKFI7hOqGfPFzR0ckbKBR041nQwPw_Tx6NPvVJyNzONx8sFsY8bksUGSIYe6wCCdY4y=w702-h935-no?authuser=0)
Then I used a slitting saw and cut off the rod cap.
(https://lh3.googleusercontent.com/pw/AM-JKLWLxrkz8zLLsMw_VV_h2O1csubzbiyO_wgEVZZIkh82lum1Uv7D5oSqPqJYEFubk1Rt20EHh1pot3cyMTBOwvC06Cm7FvNvP2gsnb4KzQI-EJkvfJkZd1ZBrUwXuZ1og626nHEGIjwcugBkhb_nX0FR=w702-h935-no?authuser=0)
The rod and rod cap shown on the print. You can see the clearance size holes in what will be the rod cap and the 4-40 tapped holes in what will become the rod body.
(https://lh3.googleusercontent.com/pw/AM-JKLWEheVjUFLhcIDrBolGzmIUXFkmBBLIA1UWepobD3edBbEO7lrz1JlUYalkPkPfmRjhTh352VMsQm3buMWOvcWW1o_8rmx8bmX_B8J7-3ZnfThPMcIaKAnS6nvyUxorEHBnnUq_o5UeHSySa26PS39i=w1247-h935-no?authuser=0)
I made some 4-40 threaded studs from a bit of brass. I very carefully turned a piece of .125" rod down to .112" and then thread it with my home-made tail stock die holder. You'll see the reason for making these studs shortly.
(https://lh3.googleusercontent.com/pw/AM-JKLW05N_g-sleBo4RRucmhdWujE9FVn4CaBd78gwUfFnPNjaK5jNGQ0ZU2U9WAh0AKac-GxfdZjMyG-XXDEs2tZExdeYNTfNhmCj3ypLfhwWNIJezUC7DzYqDvjpNJprf7XWq8GUUnBbeRMFNw_jjP6SN=w702-h935-no?authuser=0)
And the two pieces reattached using the studs and some model pattern nuts.
(https://lh3.googleusercontent.com/pw/AM-JKLX6BtGrIjw8KtLS-XJ2vwCBp8v7MwCKOTZ-9i18_JXsfVUAC7i0v6zRaI4kM-u8AgI0tn_kJrBdxjfOFIa_lmSjtArRiRbOS3G0YxCdbMUAc38jmR7tu_f1svF0dp6_LnVITzAChAdR0Y3bGqJOmGNU=w1247-h935-no?authuser=0)
Back to the mill locating a number of features and drilling center holes at 4 points to define the to-be shape of the con rod. I also carefully located, drilled, and reamed the holes for the wrist pin and for the big end. These are larger than Upshur's original plans called for and you'll see why shortly.
(https://lh3.googleusercontent.com/pw/AM-JKLUAV7yTAtovpdxJ2OwLoTo4BQY13WBZgPNjjGt9v-0jKNfpI-M-oF4vTSbNK0-BJwKuZdUHZXEZPt59XKye6v7LvPnEV1Bdz025fCug453pWnROccY7GjrmostBOHKxO6842HBQ7K3rtUjpraEps0cf=w702-h935-no?authuser=0)
Here you can see the big end after reaming to the final size, which in this case is .4375". You can see why I used brass studs as they are partially cut when reaming to the final size. I also increased the rod cap thickness a bit as I needed more meat on that piece given the much larger hole in the big end.
(https://lh3.googleusercontent.com/pw/AM-JKLVfXiRL6eu-LL-Waa_ZJaM85-X_xhDMSMyAWzu8tnamlwko-jt665jayz3RO8tNK27AM2e2ei4NWa6C2CDtydSYNkHurQzLdcJBNVqJgU60v0jkn1XVObmxROu6Z7qGwt1H01Y9dUlQgToqpSm5GpHi=w702-h935-no?authuser=0)
I also milled an extra feature on the top end, essentially a 5/16" square extension as the original stock is 5/16" thick.
(https://lh3.googleusercontent.com/pw/AM-JKLXe62Sra78G6t1u5LaAZPOxYfn2VZx4JgegWJ5OBAoGM7wEaRBb9sfgvEeXMTRVLlQqyPO9pMppJm77eJUI7vWV8NYFRFRP4Ge7tZy0BdCDUy_MLiBtzfGeyrlHpz3MkXeQwzczHDqWAvgdrAZeXcR8=w702-h935-no?authuser=0)
Then I installed my small tooling plate and located the big end and also made sure the part was parallel to the x axis using a DTI.
(https://lh3.googleusercontent.com/pw/AM-JKLVE4-_dTQeU-dv2ucaDXVw9VVBuLwXNeod1ZbX7tWqCQ4YbOzVrwLS41QnEc7biVxJx3sCGOie-W12VKxH2-K1GBX5DqLIDiThiRrJBMN_ryJQLRKn5CKayD-iWIUNpCKN7dM8_ps9Dp_OSgjxHyAqa=w702-h935-no?authuser=0)
Next I plunged in a .25" 2 flute end mill at the 4 locations previously located. I actually didn't need to locate them earlier as I used the DRO again this time and used an end mill anyway. The 4 cuts start to define the to-be shape of the con rod.
(https://lh3.googleusercontent.com/pw/AM-JKLXlDjo3gMcsSzzapGjIvb5bSDYumm3DzSGCylKCcclmkRez49iLTqcUdc4RfYVRLh1s7ycyjP7o5TREFjqDoACUdn_z6DNhbjbh4rP5hq65xFO2Q7UNANIJvQJQ51l_MjPi7Ps2taMNcq9uPy_w1te8=w702-h935-no?authuser=0)
And here you can see the rod with the operations done so far laid on the print for comparison.
(https://lh3.googleusercontent.com/pw/AM-JKLUHmI2ICwWch7Ufoya3m4Ubk5yeeCq3Fk1DzhVxMyaUEtcOZZfZamiMjbqvZmPzlc6iHeoAFSBJDF68i-F4Wu1kaYznBl1nCWEvntU6aJAnS72Vm74jb5sBPSjUowSLOxbvs40cq0wlNWJVpLD7wbC_mQ=w702-h935-no?authuser=0)
And here you can see the reason for the larger hole at the wrist pin end. I turned a simple bushing from SAE 660 bearing bronze and you can see it here laid near the con rod.
(https://lh3.googleusercontent.com/pw/AM-JKLVsX5sQMqL5TSReNuUF2_l0eyjs2u7ogplix1T1qJQSQG6U9MVZxeblSn9omIm_XGj9EwSP_bWtmEQpe36vXSvxpovCxvK0hkR-gzwQKhPz1AJqAqHr4EPSmJOFrZWHrHAB_jzth2nW6Wu0imUW3hbF=w702-h935-no?authuser=0)
And here it is pressed in place with a little Loctite 638 applied before pressing in place.
(https://lh3.googleusercontent.com/pw/AM-JKLV1sj6UMrbvuCCcTjrjnEWFN2U1YSpGzcuasWX1flMKEgzbQtouHRacony5xXC-bO9haTqLR8qxM17jXWcQepIom6Wuv4JZoxbBnU3YbMWv-umiG_FE-YPPZXshd-gYFX92HYLFlseypOcmaSChqO20=w702-h935-no?authuser=0)
And here's the start of milling one side of the con rod to a 2 degree angle with respect to the centerline. I'm using a 3/8" 4 flute end mill and I placed a 2 degree angle block under the part.
(https://lh3.googleusercontent.com/pw/AM-JKLVhWq2DJm9YkSeTdAbYtq3mZ3X4SNeh4xcVzCHdXt5XUaKtksjJ4cNQDBE4vUlSdy4mh1qIe4VZqqEVhXf3qlTcljCKN4Nyasi-4uW0468UWXZzd_D5c1LCm6BIZZSvdWChr9tJ9OX9qxThkOIuSTac=w702-h935-no?authuser=0)
Then I turned the part over and this time placed a 4 degree block on top of the previously milled edge and set it level using a DTI. If the starts are aligned, this should also give a 2 degree angle on this side of the con rod.
(https://lh3.googleusercontent.com/pw/AM-JKLXWuy_Mg3-lY8cmGwAhWEf5FnW_iXQwxhS0xLTsrtnigPc-p-vc7MJuLURuV7zYsMypJ13KviBfb6nlo60Oi4WmJQkk7-Ub2HWN_kGXUtTT2ChxhDUsSuoi6Qf_oecFnWjBo6En0nwlv-R_kovmrwGE=w702-h935-no?authuser=0)
And the con rod against the print with the operations done so far. You can start to see where this is going!
(https://lh3.googleusercontent.com/pw/AM-JKLXMDIGUCf5mCHL25CjZI2qTWuNPE_wopgTfDExuNMHaxdMAYdX8kCP2RUeLuiNl_7ewIvGYodN5z0rJnSMLpPvE-f95oUHsBKHka-kzU4dCWrzyBlN-W2WHQzH5BJ9OfcJrOMKDNtHR0R9Zbon9hQZ1=w702-h935-no?authuser=0)
Now over to the lathe. You can see the reason for both the center hole in the rod cap and for the mysterious 5/16" feature milled on the top of the rod. I'm holding that end is a 5/16" square 5c collet.
(https://lh3.googleusercontent.com/pw/AM-JKLV-3RhYOiIYaP7WEbmL62X9U8rZ3GHYf-3kCSYF-8XiHjb5vgKPkyxl6ndROv53vwGY4gCSts9Us_Rapvge339yNQH_GcB9QSQFWjI7ufBHrnyqzmg-mKzwlFGxMbVqAEQk0c_1Y6CXexAgXFjypiyP=w702-h935-no?authuser=0)
Here's some of the lathe work. I rounded the wrist pin end with a right hand tool, but had to change to a left hand tool to round the big end of the rod. I'm using a CCGT insert in a 5/8" shank tool holder. I find that these inserts work very, very well on Al.
(https://lh3.googleusercontent.com/pw/AM-JKLVO1kGLN3eleiG8b89vNkFm_ThcmL7Kv1TlT9hO425hLKjlN2kbNSjV8xZxJFjfZMhK1wJ2DuDaiIWxSSQ5ZGpVq2iQNKndmVDSgVhB9NtVQnBkPqlXLCa-0QD_IQslTa9vRCfi7GOFJ-bIub_MF1H2=w702-h935-no?authuser=0)
Here's a pix of the current progress on the rod when laid on the print.
(https://lh3.googleusercontent.com/pw/AM-JKLWgHg_xFOTjtTgaPH-BPQ4hBqqjvT_kqPsx6o0CvILX4gPkc51igsPN34hKgiJp2eQKHbxtlbEzxTCvq_uxdHpiKMr21haGOaVClgSn4wU71ri7hofRXcHX26sOQRTwOPyqrpfA3qpsNEZSqgDE_xyB=w702-h935-no?authuser=0)
And here's another pix from the rod's side so that you can see the shape from this perspective.
(https://lh3.googleusercontent.com/pw/AM-JKLWSYqCJHJoiTT1l8iAnYVairKSWm7ezZZAGM4q3L7JckH-w4NcjxNVHe3if6r52joleX_MijIZD6_xyZZOBgMpfXTZh5iWGxnqSa5zeHRXuoF_9Nzxwi_KeU8Fj1snI-pscOu0IEP93dQaQO5MUQk6_Og=w702-h935-no?authuser=0)
And by now probably everyone has figured out that I'm gong to attempt to make and install a split bronze bushing for the big end of this con rod. So I had a piece of 3/4" SAE 660 bearing bronze and shown is turning it down to .625" to start the process of making the split bushing. Shown is a short length turned to .625" and being parted off.
(https://lh3.googleusercontent.com/pw/AM-JKLUQRQGgadouMcL2WM1lW7WqKzi1k4zIEQektihfC1qYOGFj-tT4658DQqXcITb9B0I__UOSWnHZXNToV0_XynsTi567vZhRDOwtHD31GVkv57zB00yPCKTdbG68IyR0FPVBC6Mnx7d0nZCR97dL7Sb5=w702-h935-no?authuser=0)
And here's the bearing bronze shown on top of the print which shows how the bushing will be made.
(https://lh3.googleusercontent.com/pw/AM-JKLWsxbu5nWeFfKMIz50viJsQqyyBixLd6plskYHKlm626Jnb1q0Fb1gMSTySGALxXQZBPogY2mR8mdwzKIubp_UeA8B-ttLP6JpGsPH_8mmP78O7DRZiFpuTmhfT8rpVSdGxFrjnRmrzUoqVnx5gHMJe=w702-h935-no?authuser=0)
Then over to the mill with the stock installed in a collet block and being split as deeply as I could with a slitting saw. I used the thinnest saw I had, .012" so that I removed the smallest amount of material possible.
(https://lh3.googleusercontent.com/pw/AM-JKLV0UgGME21VRgqCDtIzA5J60aeFleaYSYh0X-7eW98Be7ZdANTnvWfcHyka2lVHmjeNrDE-40cbW38lzozKZfTPQ3jxFE4HnVlAjrs29Yim6-Uh3qz8qzjLsRAc5P4ngyNY5_Rr4bMXziha7SVa89Vk=w702-h935-no?authuser=0)
And the split bearing bronze after parting it off from the main bit of stock.
(https://lh3.googleusercontent.com/pw/AM-JKLXYxETSMn9XesHHiUTZRXPr-Mbo7o0-addLK0dpLDSNI1337Sp_iMA16SOdDF5QNuHijsTPKcZi1kCwtl8qyUVRHnDPbsaj2CpA_XXcE0R4Hv6WNLZlnlbsj49r0yM7WbmWGU9fESq-2-oRq4DteWLh=w702-h935-no?authuser=0)
Over to the welding table showing the materials I'll be using. I've roughed up the flat sides of both pieces using some 120 grit emery. For this sort of soldering, I like to use the 'tinning flux' type material as it has some finely ground solder within the flux. I'm also using the Harris 4% silver "lead free" plumber's solder. I find that this solder melts beautifully and bonds well.
(https://lh3.googleusercontent.com/pw/AM-JKLWu0eDBXKxVykiiAVYfRHJdea1ncrMKUuHJt-TB92ceeovqvAuVoaL3FfEXhb-ilnnT_sUjaL3FCqgH9TxoDvGJ2CF8KtletsGK5THugygO7tVpqrROrieC-27SkOQPOkjOd4PSkyWM6gK0IjuduWns=w1247-h935-no?authuser=0)
After fluxing both halves of the bronze material.
(https://lh3.googleusercontent.com/pw/AM-JKLWzizA1zju-P8EUlqadgvlZ0JlYTCacFFiL09HvTmNWkz9CgPFGk3fNHPpbz9dgKJ58nFuZsFphmtAZE-3MNsC-wztxGDXYop7-uSQZufQeSkh4rUH0AT2qNx2ZLhLAKlHGYPzZ255K5kvwdYKswDeK=w702-h935-no?authuser=0)
And here's the operation ready to proceed. I secured the two halves together with a couple of twists of some annealed steel wire. Heat will be applied by this very standard plumber's torch.
(https://lh3.googleusercontent.com/pw/AM-JKLU6IhgQWapNjgsrFIzcbe7a2t0bcIgm2AyBkk1NoX7jEjNqdOSj7iib4bJ0ouiogW8m0DE4n0GJjXQ9nlgroliJ9M3YGKktitAELYOxIDFmafnWgDI840Y5E-Xx6BFC6F0DQNN_qb1OtAnK-h0WzBW6=w702-h935-no?authuser=0)
And here's the part after soldering. I applied heat to the body of the part and then touched the solder to the top of the 2 pieces when they got hot enough. The solder wicked completely through both parts and was visible at the side seam and at the bottom of the parts when completed. This is the top of the part after soldering.
(https://lh3.googleusercontent.com/pw/AM-JKLUnUsI7ErfaFC9pf8v51oTyTYs-bsRBEMvPZph3XfnyU1ics2CG_hkuA0Er3sv9tqKC7wrxf8wRCnVWfqyj_eA0C6p0-adC_dE_nk3e0soh7s6tOIQf06UmSnnfK0mjQhpv85O1Mdf4BVCl2XNSUYUa=w702-h935-no?authuser=0)
And here you can see the bottom of the part after soldering. Notice the solder flowed completely through the joint.
(https://lh3.googleusercontent.com/pw/AM-JKLWJLLaX7xbHACjrtlqntZTZI4F6p48v93AjfSNiGDqhROakRwtf6BSF30fhIplhLQ5DhyRj_h4M_xs3m2MtlNc07V8R7RGhG3fJeMjsMmGWKEst7ezv-wOgQLAM3mMpcyr3IL_bDMG1LzWP2tvvhzYQ=w702-h935-no?authuser=0)
Since the part is not truly round anymore, I went back to the lathe and was still able to grip it with a 5/8" collet even though it's oblong about the amount of the cut. During this operation, I took the OD down to .562", still oversize for where I need to end up, but now that end is completely round.
(https://lh3.googleusercontent.com/pw/AM-JKLWcUMPqiBj0GKgMYHQAYPIEIxAeInxp21_0ptiCdlV1rTG1P1h2-_1X8t5fOT8ypyN7VCJf0F9JpE65XLW_HFTKlPgThc01yChXaD-4qxdS6tzUKfT7FU3R38DhsIPYrUlULNJiFOO5_57KaMN8v4uX=w702-h935-no?authuser=0)
And here's the bronze after turning one end back to round. The solder joint is barely visible after turning the OD down.
(https://lh3.googleusercontent.com/pw/AM-JKLWQvP4ROzraaIgObYfn_v9Ao-pvV0-L2exlFOt0oDA1TaCy2B8AP1JbINYlFz7cbrXl6P2XbJL3WcV1Zhzs4fddIZlb2KaC1U-s7JrwN-E4dGQlH8UXIsgNyg8_PGiB7SEBrZ468cbVwtcgFf0vS3P0=w702-h935-no?authuser=0)
I didn't show the operations on the lathe was it was just some turning to the final OD and creating the .437 OD with a groove/turn/parting tool. Here's the bronze to-be bearing on the print.
(https://lh3.googleusercontent.com/pw/AM-JKLWJoV7VMJTYRZrz31nwf7QzXg7uLBwQJWA2czrXPJsultVcT2rQjvY847p0tBYyIm5SAkJFOF8NZrEwckKAeIlV2lfgsCInzp_5oScWVVudjXvFZ_U6L2gC9afvnQT603sR0rv2aWlNagr2B2TA7o8A=w702-h935-no?authuser=0)
Next was over to the mill with the part installed in a collet block. Shown is aligning the solder line as close to horizontal as possible, just by eye and comparing it with a parallel for reference. After I got it as close as possible, I took it back out of the vise and tightened the collet securely.
(https://lh3.googleusercontent.com/pw/AM-JKLVc-_Prk3r2WMTDVWcu6VruLsfX-daI-7vph0K6B4SabrH26yS2aTzczYdUmeRFxMDECYtgsxWhzl64RKdIfkjC1_u89irBF_09URPXgeX5BJNlm2ls2xw_qB-qQrT6nczaXThuO9Z-p6h2bb8DcnlV=w702-h935-no?authuser=0)
Then I created the relief areas for the 4-40 cap screws by plunging in with a .125" end mill. I located the end of the part and the centerline and using the DRO to place the cutter appropriately.
(https://lh3.googleusercontent.com/pw/AM-JKLXM2nktXXol4DQ6N3mKDY45lQdTfG_f7QdmO3V4YKAgn4zRz7YXkRunmvxdKzTkkPGylvF8EhtR2P4Gk8Acu1k5MwzWxbqtKecU0vx-ue7rpLRuQNT-2LZOkShxG_CZlMUyTc9Toghy5we__THcqWsj=w702-h935-no?authuser=0)
Checking the fit of the con rod big end on the bushing. I wanted to make sure there was sufficient clearance for the cap screws before tearing the setup down.
(https://lh3.googleusercontent.com/pw/AM-JKLUHycfvgXXVPYxCZPnez_ulu3p0HrrtBhUOU0HJ_kQDvr3iLOXLZWFZrsIuxGyPnDiDDy0c4953vdGmEXLa52hTeafJg6y7bCTqPwY069ssFBJd-RJsMz32B2qFbWrqUTAldULS8wGiWoFDKmNNJgCF=w702-h935-no?authuser=0)
And here's the bushing on the print showing the relief areas.
(https://lh3.googleusercontent.com/pw/AM-JKLXPHq0vRibUWHa17sIkGQRHnIvlSYELuNSBmR0DQsCYd-SXgejpohJLFf2IDqQhiT5xB0gcKiFCQxDYlCBpX8dN8pfknZYR2kTU7qIh7U8WHQiktMv_fCyJJGkxrrTY2MA0O4anitZvywIQ3u_HvkTH=w1247-h935-no?authuser=0)
I didn't show the remaining operations on the lathe. I was going to but things happened rather fast. First I drilled thru the part and then reaming it .001" under 5/16". I then went to part off the bushing and just when the parting operation completed, the part actually split right at the solder line. I think what happened was that there simply wasn't enough material left to withstand the pressure from the parting operation. But luckily the bushing halves were completely fine and their shown against the print, along with the con rod and the brass studs that were sacrificed during drilling/reaming the big end of the rod.
(https://lh3.googleusercontent.com/pw/AM-JKLX3aFGnm4NteF1Xd53mE_ZxTYXjcrnSZCmNqCkM6ZUghnF_J10CoJZ4EkxE_ji5xViQtiqwT2j3SjAG-dwbgQL_VILDi5o9WKnpCCBqTclcxEpWRfFJUPk_XIB-naTnoL9oCEZUy4maKFLVyEhdcrzy=w702-h935-no?authuser=0)
Then back to the rod. Here's the setup to remove the holding piece from the small end of the round and to round it over. I made an alignment pin for the center of the rotary table, .75" by .1875" to center the rod. Then I placed a scrap piece of Al under the rod and secured it with a couple of toe clamps, centered the RT under the spindle, moved off by the radius in y and rotated the RT to round the end.
(https://lh3.googleusercontent.com/pw/AM-JKLWDgpQUglwUO6gd92clCtKDoyiCBR41z5Qu_PgJxgy06m3ldZcUd1R1sN3M-yN2OYN4pKWjbttxmKcFnXgQxr3XRaPsGpRwyUz7oPRrUcdhRQ8abXB8OjdULotFCSD-X1EeMFVnVca8u6hICzotBcjy=w702-h935-no?authuser=0)
And here's the rod with the small end rounded. It's interesting how the two rounded features intersect and make what I think is a rather nice looking feature.
(https://lh3.googleusercontent.com/pw/AM-JKLXNArAmMO_FBbsIUTUpASrAxQ12fIw8_4QKLblpKIBXOBffQacnmcZyi-WZbrbr3rs83vQpTx0zj3hI8Yy7TG6YRmY71Mg8_vVTFUV6k2pZupubA51jJZNuknDJG7VWPyjxQdp5kK8Rqw2obhXXlec5=w702-h935-no?authuser=0)
Here's a close up view of the small end of the rod with the operations done so far.
(https://lh3.googleusercontent.com/pw/AM-JKLUEIg8qnDBB3yK76Y1nYb1RzFnKMOXQCDtSPuVAtf0zq2kWn_QwNuiM3Xfe26fhocxR9ajjspS_4iHP15WaC44sgn32s9KYcS95CPUsvYYCvFtJnOJNE0e29mOOQbefHlIjerVz7l28fmLfyopn2tQn=w702-h935-no?authuser=0)
Next the thickness of the rod body needs to be reduced from .3125 to .25" everywhere except at the small end. So I reinstalled it on the rotary table, moved out the radius plus 1/2 the cutter diameter and rotated the table 360. I repeated the same operation on the other side of the rod also.
(https://lh3.googleusercontent.com/pw/AM-JKLVdWeOt_iMByCgBIH9gBNzfctJdz7LEb3ar9gVPnMk1YTSDonhUmDPQDYLVBjIDgQcK1hL9WgOODLRQrPAwxNIrOFtwmyYJN5wS_249vS_db6LKou4x5xtS6-gDaZgmZ8c17ZluEK2_h8LxHUB1m0pm=w702-h935-no?authuser=0)
And here's the small end after thinning both side using the rotary table.
(https://lh3.googleusercontent.com/pw/AM-JKLXoa3x2MaRw5zMAV3NYxqBOt5vM4yaKE5rCSdKTbLure3ew3Ww0xaepBErIyLhYbXkGARA9cX90dSI95LyPMjrPLCS5-PM_C6imObEcUs-QuL8iG_PvudkvWVIQ4sRIQ5LXq-y2n7Zq3YgzzYVFj-TG=w702-h935-no?authuser=0)
Then back to the tooling plate to then the remaining sides of the rod. I secured it and then moved the toe clamps as necessary to get to all parts of the rod body. When I flipped it over, I placed a bit of flat, scrap Al under the previously milled area and moved the clamps as required to remove the material from the current side.
(https://lh3.googleusercontent.com/pw/AM-JKLVfvIBwvSCEKys_j55FmYBHMXUb259eqI42PcWyZFjUj-xCaXVAbUfx80YSLsRWyhWrzrwxsTnlZbK7GjA1mNtukgK74dF3XlV8Ajd6Cq1CjN23pBAfIcJfc27GZmfCUuDlqBxNa4_bi5qTOL7E9HfR=w702-h935-no?authuser=0)
And here's the rod profile after the thinning operation was completed.
(https://lh3.googleusercontent.com/pw/AM-JKLVxyNTnp24U6BxUbCC5nELG5MYHM-Q60tu85ViPE4w42ZH-iVFFHKk57EA_yeUQrvg6_jHBFt8gLYqI1psQCOM3uYLDHWjWpmsxZoeXgS-7tRqrG1miabjYpVzQF2ASIL02wD6xo2s9N_19CUqI_UmU=w702-h935-no?authuser=0)
Then, since the bushing isn't guaranteed to be perfectly round, and I'd reamed it undersize, I then reamed it first to 5/16" and then finally to .001" over size. I did this just by hand with the reamer in the bench vise and turning the rod by hand.
(https://lh3.googleusercontent.com/pw/AM-JKLXIBdavlZemfg7zmS9ivshMnD4G5DvjQzyvLy-rm3E7Qbh8v19bxbuexvW4ClOR0hoqvHtAxGlRrqlSodDbIVYq_av21XGUJIDD_1DSoQlAyNG7duJuV9ZymagcNwful51c5P8iAD0YS8A11GiDrXcz=w702-h935-no?authuser=0)
Lastly, I drilled a 1/16" oil hole in both the small end and the big end. My thought is that I can periodically put a drop of oil on both of these locations and hopefully that will be good enough given this is bearing bronze. The bushing halves fit quite securely in the rod and rod cap but I also put a small drop of Loctite 638 under each half of the bushing prior to installing and tightening down the rod cap.
(https://lh3.googleusercontent.com/pw/AM-JKLVtslPGineuleVCqxbTjARr_D2kcUjNdw8Pt7IjhQLsPZtpbQKc339wFNOOde_UVofxeUiOZgQpuyRLzdh0_ZfcX0NDcClA4uPa1UQuZBgDVAwuz2Jmo557tVgUTT-Sy3wuQsO2XjU2bVy_upaYI4tm=w702-h935-no?authuser=0)
And here's the wrist pin, piston, and con rod ready for assembly.
(https://lh3.googleusercontent.com/pw/AM-JKLV4ya5uSDY7xNW9QGLm-IxG6PuQ2qlt-6ZLPYLdkZy4uD-TGP9u9l-5bfQmlHBqitztLFNmDMS6qe9Vp7QLH4SWQhBwqueJh-RtGA6MBj41xBK3AfSn0noNSLnp3mgva8jcJxSNq6kJKWs2gcIptO15=w702-h935-no?authuser=0)
And here's all the major parts assembled and checked for rotation. I do notice that the piston skirt protrudes below the cylinder bottom by about .20" or so. Is that correct? I can't find any mistakes in the dimension so I assume so, but I'd like to be sure.
(https://lh3.googleusercontent.com/pw/AM-JKLUbwzWnnG87qgU-LrLNIjiyNFJ8aWGy0AYN9wJgn_BjefNYJgXKLPHskvR2_udu1U8sdMCys9qqzqnRpI8tDaMQTRTH3XQE1D7y7z6YYPenN1kO4QLOBOhiYzuOgb2tpS8mHzJNz_ihiznkJYsq2TjN=w702-h935-no?authuser=0)
And here's a pix from the top when at TDC. The piston is also about .20" below the top face of the cylinder which I also assume to be correct, but I'd like anyone with experience with this engine to comment.
(https://lh3.googleusercontent.com/pw/AM-JKLWPjOsDslKxpEaRlKaBRTGpHXJ5BE4KOCuhfz-WBJnZ8w5fujTKzAflIPYCs7hDFd18-_wnK6DFvKRk6XG0nERaFujBUzMCVZPHw1H8Y6Qqg8m9j3XM_gY-1ylltwpeo1Fv8tT9DzK53C-DuwvDTa952A=w702-h935-no?authuser=0)
And that's finally it!
One of the other reasons I built the con rod this way is that I next want to build a Farm Boy and the con rod design for that engine is very similar to the way I built this one so I felt that this was a good way to gain experience.
Sorry for the length of this post, but I did want to give sufficient detail for others to attempt the same.
Enjoy!
Mike
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Great sequence, great results!
:popcorn: :popcorn: :popcorn:
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Nice job on the con rod, Mike! :ThumbsUp:
The fun part of our semi-parallel builds is seeing the outcome of our sometimes different approaches to the same part. :cheers:
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Nice job on the con rod, Mike! :ThumbsUp:
The fun part of our semi-parallel builds is seeing the outcome of our sometimes different approaches to the same part. :cheers:
Yes, it's actually quite interesting to see how differently a part with the same functionality can be done so differently! I like your approach quite a bit and a thought about making the con rod about the same way that you did out of a piece of Al bronze, but I wanted to go the lighter weight approach and I wanted to practice for the Farm Boy engine that I want to attempt someday.
Keep up the good work on your engine!
Mike
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Great write-up, Mike, and a good set of ops to get it done. I appreciated your step-by-step approach! :popcorn: :popcorn:
Kim
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And here's all the major parts assembled and checked for rotation. I do notice that the piston skirt protrudes below the cylinder bottom by about .20" or so. Is that correct? I can't find any mistakes in the dimension so I assume so, but I'd like to be sure.
Hi Mike. I got my piston made yesterday, and assembled it all together earlier today. My piston skirt also protrudes about the same amount out the bottom.
And here's a pix from the top when at TDC. The piston is also about .20" below the top face of the cylinder which I also assume to be correct, but I'd like anyone with experience with this engine to comment.
My piston is 0.312" below the top of the cylinder at TDC. That seems like a big difference. Did you measure yours, or just eye ball it? I checked all my relevant parts against the drawings and can't find an error.
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And here's all the major parts assembled and checked for rotation. I do notice that the piston skirt protrudes below the cylinder bottom by about .20" or so. Is that correct? I can't find any mistakes in the dimension so I assume so, but I'd like to be sure.
Hi Mike. I got my piston made yesterday, and assembled it all together earlier today. My piston skirt also protrudes about the same amount out the bottom.
And here's a pix from the top when at TDC. The piston is also about .20" below the top face of the cylinder which I also assume to be correct, but I'd like anyone with experience with this engine to comment.
My piston is 0.312" below the top of the cylinder at TDC. That seems like a big difference. Did you measure yours, or just eye ball it? I checked all my relevant parts against the drawings and can't find an error.
Ron, in the morning, I'll pull the head off and check the distance from the top of the cylinder to the top of the piston at TDC. I'll report back here on the exact measurement. I was just eyeballing it when I said .20" originally.
FYI.
Mike
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Ron, I just measured the various piston positions on my engine. See the following:
- The skirt of the piston is about .18" below the bottom of the cylinder when at BDC.
- The top of the piston is about .31" below the top of the cylinder at TDC.
- The top of the piston is about 1.31" below the top of the cylinder at BDC.
So, my initial 'just looking at it' observation was incorrect. And shockingly enough, the stroke appears to be right at 1"!!
So given that we're seeing about the same thing on both of our engines, it's a good bet that they're correct. At least that's my sincere hope!
FYI.
Mike
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Ron, one more bit of followup regarding the piston position with respect to the cylinder.
I finally did what I should have done originally and that is, go back to my CAD model and look at it! I had made it so that it rotates correctly and so I checked the piston distances at TDC and BDC.
What I noted in the model as follows:
At TDC the piston is .313" below the top of the cylinder.
At BDC is the piston is 1.313" below the top of the cylinder and protrudes by .188" from the bottom of the cylinder.
So that's another good data point that what we're both seeing is correct.
FYI.
Mike
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Thanks Mike, that is a good data point.
But since my measured number at TDC is 0.001" off, I guess I'll have to turn myself in to the Machining Accuracy Police in the morning. Or should it be the Measurement Precision Police? :-\
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Thanks Mike, that is a good data point.
But since my measured number at TDC is 0.001" off, I guess I'll have to turn myself in to the Machining Accuracy Police in the morning. Or should it be the Measurement Precision Police? :-\
Lol! You'll just have to have all your measuring kit sent off to calibration lab and certified at tremendous expense!! The problem has to be with the instruments! :ROFL: :lolb:
Good work!
Mike
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And here's my next post on several small parts that I made.
First is the valve rod guide block that's unique to the hit-n-miss feature.
I had a bit of brass that I milled to dimension and then drilled two holes as indicated on the drawing. Shown is the first drilling operation on the mill after locating the edges of the stock. Nothing terribly exciting here.
(https://lh3.googleusercontent.com/pw/AM-JKLUe1szlPOly7FMtOz7x7emQD3qo71NdrEO1Z8E7bIFbkF_2cxJG0_mOUfyx3m5s5vrRZTLbwGd9GwsRJWv3ygv2Bwje7isbN3FuFZav8qfEj7IA04DrOlz0VT1ZGspTLQLl0EAkTk0YJPgEZKslQhvf=w720-h960-no?authuser=0)
And the finished block on the print after a bit of cleanup with some 400 grit paper laid on a flat surface.
(https://lh3.googleusercontent.com/pw/AM-JKLXOfJpmlDsghI9PuXcjT4lOXS7vMeYndUfB04hI8f4ZI-rVz00R92aPJaMBAH-LF__HnMABOAtMeNbemqK2B-9LkjCsV8MC3xxOlX8GxYnsCycTRckjHIUhfuhS6CfytLHOJuz0vnphHRP4BMpUGCsw=w720-h960-no?authuser=0)
And here's the guide block shown in place on the partially assembled engine.
(https://lh3.googleusercontent.com/pw/AM-JKLXyRiboWtq203k4ohHKVzAoMWKGzJYqaU8LkAqbNZteQVMpQ9LukP3gWxh36Od7suyc_tMBECtmLxly5RXZ9BuvYH459I4t5DJqJGqM8eSKavmRR3N-MHROVyjF5ZNQiyn2xetmG_tz1_aj4c_dG6Rf=w1268-h951-no?authuser=0)
I also made a small brass block to act as the catch stop on the valve rod. I designed this to be square as I thought it might offer a better edge to the lever edge to engage, but that's really just a guess on my part. I won't know until I'm able to try it out.
This part turned out to be a lot of trouble as i didn't have any small square rod stock. I first tried to make it from a larger piece of flat brass stock, but I ended up with no good way to hold it and managed to crush it out of shape in the mill vise. So I started over with a piece of round brass stock and made the end square in a collet block held in the mill vise.
(https://lh3.googleusercontent.com/pw/AM-JKLX6DT6GgCf0iXGqNRBlTdnbeDTT3H6vUQ6oMgae1Jd2zjGgkKYArcwx7mrvGRa5g174F7aLy--UmL7WXnJHPx6LKko_GTzqm3lSbeCMJ15cZ5m-dcqO5t_o1yuq7HhJcDa7_J-7NS0z7w_nr4paJIo0=w720-h960-no?authuser=0)
Then I stood up the collet block in the mill vise, made sure it's square and drilled a clearance hole through it, offset to the edge, for the valve rod.
(https://lh3.googleusercontent.com/pw/AM-JKLVnii48pshmfKSOQnDlG2Mpu5MbwXpHLphwxQlHDGQ9LPRFabMhguwMSI9ZB5iyDFAsM0zvMdpkZbT0bd0RMpfwc1xT_loSvTpdHv1XkUQTgYwxzSlB1eVg_yzLLrSp_013eodJoIc0FdPLFq6cdpb6=w720-h960-no?authuser=0)
Next I turned the collet block back on its side and drilled and tapped for a 4-40 setscrew to secure the block to the valve rod and to make it adjustable. Upshur's plans call for Loctite'ing a block in place, but I thought it would be more wise to have it adjustable as I'm sure it's going to be tricky to setup the hit-n-miss mechanism and I wanted to give myself every chance for success.
(https://lh3.googleusercontent.com/pw/AM-JKLW0AedLdnOgis9tXaQiVMiCueo8uBdIKh3qvlOSvLl-W_YkqjAkpEXKP8rspLoqKu6iYTkSmuorPBtqrO_h0ipvBT9SIMwMuMQu_U0B7c4jk_KERV9e-e7_ZsFCcVW0wF6T0nLgLoicqgBzsrI8qlwr=w720-h960-no?authuser=0)
To finish the part, I simply sawed it off the rod using a slitting saw.
(https://lh3.googleusercontent.com/pw/AM-JKLXwg4luwaU_L0utqKSpBE3NHxxtjVXKbWF3ZHnj49uWFZwPT_B1yIEoqpu_Y9E-46SKhMWwrqj62x3suLrnsXV83_h5esXtnk3yTDMKaCDhZvBbUVkmpR6oVsa4h2XHmNfYQgAfPUcp2BZRH-YdBWmn=w720-h960-no?authuser=0)
Here's the troublesome little block laid on top of a dime for comparison.
(https://lh3.googleusercontent.com/pw/AM-JKLVh8IzsCLoX_xQn7VjPNIpLn72sADTugjFeKd1ETSqVZ82jL83LBLzudnnShWJT2hXv8ElQngASlHWZnHqR6fo5C91qof6wU6HvjGD6bgFtS2p9-9dsz8PJ1JNtozTADpgnZL1S9sFrFWDVSbd--aMQ=w720-h960-no?authuser=0)
And the block test fitted to the valve rod on the partially assembled engine.
(https://lh3.googleusercontent.com/pw/AM-JKLWuupBhw84p7tUfjLB_QA75tpsx82QohTMbLTTJ6Zsslh1Q74VG0fgomlGDZQdbF2x7PqtMalsoosbDks6AO69B5rXWme8IRDAJEUeES05kQzGzqCVM0u31SEJNs_12UbsHLDGEuaQMAl4r8bc0J1wt=w720-h960-no?authuser=0)
And here's the head with everything assembled that I'd built so far. This picture is important and tragedy will soon follow. Note the small flush Al plug that I used to blank off the top of the thru-hole that forms the path to the spark plug. That a 20P British coin for size comparison. I noted that the Queen was not smiling as she knew what was about to happen.
(https://lh3.googleusercontent.com/pw/AM-JKLX9Hnmdm-Rac2t6JTH_0KC65MgNxIh1rCuW2sDbII-hPaYdI1GJuigIfKXq_IXaG4TwDb0G-IV6QKpVFxsiX_cTPo55BcY9LjirEyznz7U8_H058UvLEDjAJZPN-86t4O9ZAHgwxHZxjvRbIlTV_bQx=w720-h960-no?authuser=0)
I'll post a few more pix before i explain the tragedy.
Here are the valve retainer caps. No pix of making them as it was just straightforward lathe work on a bit of brass rod stock. These are slightly different than Upshur's design as I made a small recess that holds the retaining pin in place when installed. The Queen actually smiled and approved of these bits.
(https://lh3.googleusercontent.com/pw/AM-JKLWEcMUbRVCH7-Ozv3yorTKgtDtvnAkN70lXBWJeP4ZFWenxapsLjVSw8JMNA_Q-yQRVZes0zqd1QN2xBvB54o5wZhFXA5aRYATvAsOTy2ipE6BBMVexAy0C4Jflne7-iLAOpwutgQK89I5BSTm9BEHB=w720-h960-no?authuser=0)
On to the valves. For my Webster engine I made the valves in one piece, but I wanted to try 2 piece valves on this engine as turning down a .25" rod to .0938" is extremely slow and a bit painful to me. So these are just 2 bits of .250 drill rod, drilled and reamed to 3/32" and parts off just a bit over .10".
(https://lh3.googleusercontent.com/pw/AM-JKLUJKf_xTIr8sJWP6UU_9oXgE_Pv0BhYS1DnYHPm_Ec5xt6G0nCfWICZos-qfkAZiDd8s3OjQ-kSUv3w2haBUtsfAMYnfGG8vh51WtE-fkyqOi5-wKESELR9HCT1ySJ-4bHtt8xVdo0AaPfC1hv1r1Al=w720-h960-no?authuser=0)
I drilled .040" holes .10" from the end of each to-be valve stem. I find it easiest to hold the stock in a collet block, find center of it, find the end of the rod and then spot drill and drill thru with a #60 drill with the Bridgeport running as fast as it can go. Here's the 20P coin for comparison as otherwise, it's hard to see.
(https://lh3.googleusercontent.com/pw/AM-JKLWmP9tTplQo2TlF0Hgl5XwzMGgPUxn33GF43JBJJ7Cu7V1e-1FTKps5LqAeH_FNltLr6S52nvEc2nMCTA7Lka3WZN6UXPNR6irZex18M9vCY9OGb_mbWB996xUe6jtKYIV9xvQagMMoCjBnY9JSKYKn=w720-h960-no?authuser=0)
Here's one of the valves ready for silver brazing. I used Harris Safety-Silv 56 along with Harris flux for the brazing. I cleaned the parts with carb cleaner and then fluxed the end of the rod and the ID of the head. I cut a very small piece of the brazing material off the roll and placed it on the head of the valve and applied heat with a plumber's torch. To hold the head of the valve in place, I very slightly dimpled the top of it with a punch.
(https://lh3.googleusercontent.com/pw/AM-JKLVv3wlrluJLgUFc_y1Seu_Lv0y_-uQ8kCUKbDjwufk9r4YmmYA5xeapj5StPkKglBNih08de4u8wS30yLqfP9_NegM0osQWS-Dq_nb5V4LsDHvSNvy1Hl9ma0UQEeD1izUDH3OKi7HN6o-p46CBF7sr=w720-h960-no?authuser=0)
One of the valves after brazing but before cleaning it up and turning the head in the lathe.
(https://lh3.googleusercontent.com/pw/AM-JKLUYBa0n4jQpgGId0dPVA0II9OM2IWSfxFVnJno4qpTzYTcvbY3z8JQs0uIChKcz65wFoc_b69HMyPKzYL8Oh-oCjHDBEHGlcTPdDTTV485g5mIj6yyc467G55LZRU7WCLccEthav2iyt1NOzlqSU9Yt=w720-h960-no?authuser=0)
Here's a pix of 3 valves after being cleaned up bur prior to turning the heads. I actually made qty 4 valves and ended up with 2 good ones.
(https://lh3.googleusercontent.com/pw/AM-JKLVuQ1FQVYQcOIOYcSgbqN_XLyoufrBNu765Rg0Skz97pWOOqnQKw5Gdi3d07PkvJ3Sb2Fd2mBslwQ1nNOTv6WcsulDyoOYOOcCczZAj0lkpqGZM6L-NwTtOQx36INrwCSXO7exu1d1RBKj8Pcpi58YN=w720-h960-no?authuser=0)
Here's a pix of what happened to one of the valves when I started trying to turn the 45 degree angle on it. I was using the wrong tool and tried too large of a cut with the valve held a bit too far out in the collet. I managed to ruin 2 valves in a similar fashion before I figured out how to do it successfully.
(https://lh3.googleusercontent.com/pw/AM-JKLWC7iG0UtC9oB7F63acRZgeKY2GG2Tf5pzq7wd_czKlupcyqTr5lr1kbNdQZLV30D1TqtukcaPn2HFSFYckMuh0n1U60F_1yU5PUb0ak2Y0ub1uC7RfkrpQIdIwHO2ko54nhNQkX3xheNVTFlIheM1D=w720-h960-no?authuser=0)
This is the setup for turning the backside of the valve. This turned out to work well. I used my 2mm groove/turn/part tool engaging just the corner of it with the work. I fed it in using the compound and very gently advanced the cut using the carriage. Using this tool allowed the valve stem to be held to the maximum length possible in the collet. And it cut very well.
(https://lh3.googleusercontent.com/pw/AM-JKLXG4VsvGBc7D2gEK1KW-91gkk94KlT1pad1GiCGetIljEbeesrxbHA6nVOgT8ewHW3XPIZDxNQ4DMFcLDjJzWzb33lgZzCX__Rg3Td-VnnhJ6MUVn3vUN27cuCl1zK2lI3mVYssq6EUuL241DjNFDPa=w720-h960-no?authuser=0)
And here's 2 valves successfully completed! Note that the silver braze completely penetrated the valve head and it formed a nice fillet on this side.
(https://lh3.googleusercontent.com/pw/AM-JKLVrrA1RT40cwsTboLA8lYduWym0rZoEsXRSAYa_4yj3uaTfvKqJ36lIzZgUiRKWvIQoCVeK7MH5TSFFcITS1cV2yvwrcK7sb6k5MBTFnI05IkLrOxlr9-w6vzZkahoqOQUQ4rXojzIMbvo7ReDQpVoL=w720-h960-no?authuser=0)
And a pix of the top of the valves. You can see that the brazing material completely surrounds the inserted rod, so I'm pretty comfortable of their strength.
(https://lh3.googleusercontent.com/pw/AM-JKLVMa8dlwRWSw2DRfBtKJ48C2m0Njf0_L-Jv-VzkNJtVCtOVdjm2kPeuBRQQa5FtjR5S0iw5i4pEcSWeD4zDU7qtjUwMow1qhcCH7H8Ig5gOJTVsVXxljDHFFYh7c86u1EW_5pOJ6aciGBGLM6qdWiXI=w720-h960-no?authuser=0)
I also made the valve springs using my home made guide tool in the toolpost and a mandrel for forming the spring held in a collet. I used whatever The Machinery Handbook specified for the mandrel OD for each wire size and the springs came out OK. I wound the springs by setting up for threading at 14 tpi and holding a bit of tension on the music wire and simply running the lathe at the slowest speed possible for just a few seconds.
(https://lh3.googleusercontent.com/pw/AM-JKLWk-QXAwci_rnDVwjHX9HAQxFuegfhoGlryqhrBY9Ac5D2SWTK9hU1p8icOmIRPiQygYm7m33xNJhpC4DmAkYBylaT9wYdEpVv9L7bp9EgRaiiwqK78L_oCZG6ivLdTe5AsVJroYOUPpJ-5fRMlDaZ7=w720-h960-no?authuser=0)
And here are the two springs after making them and cutting them to length. One was from .014" and the other was from .022" music wire exactly as per Upshur's spec. I also made the head gasket on my Silhouette cutter. I used .015" Fel-Pro Karropak gasket material. I had tried sheet teflon on my Webster but I found that under the heat and pressure of running, it tended to soften and extrude and the seal would fail. The Fel-Pro material seemed to work much better for me as the heat doesn't seem to bother it. I've previously documented how I made gaskets in a separate thread so please refer to that for more details on my process.
(https://lh3.googleusercontent.com/pw/AM-JKLXmA9JxO_xweES3iPJffTfM4iJeZjU3Mq_O_fCCvaz4OuicUOX6_FrWMpI_LGHE0OP5Wr0YW7b_1UosddgW_QpD93wEp4yYDXziFJrXGRXU5endafWh0NZ98g7Hhfh8UHXmz3yiVrupFQ1P75I7b2_H=w1268-h951-no?authuser=0)
This post is probably long enough so I'll conclude this now.
Enjoy!
Mike
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Mike- Did you indicate the valve stems in the collet to make sure they were running true? That would be my big worry making two piece valves. Parts don’t always run true in collets.
-Bob
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Mike- Did you indicate the valve stems in the collet to make sure they were running true? That would be my big worry making two piece valves. Parts don’t always run true in collets.
-Bob
Bob, indeed I did indicate them. I'm pretty lucky as my collets are all pretty good quality and even though I bought my lathe and related bits used, the spindle runs very, very true, at least as best as I can tell with a DTI. But I also think the process I followed, that is after silver brazing the head to the stem then cleaning them up and turning the OD, face, and 45 degree angle on the back side, the head of the valve pretty much has to be true to the stem in any case. I've not yet shown the pix, but I did lap the valves in and pressure test them and they hold pressure on my test rig.
I have done one piece valves also and they also work, but I wanted to try the silver brazing method as turned down a .25" piece of drill rod to .093" is a bit slow and painful and I manage to ruin several in the process typically, although I'm getting better at that method.
Thanks for taking a look at this thread!
MIke
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Hi Mike. I like your method of turning the angled faces on your valves. I made mine pretty much the same way, but my technique at that point was not as good and shows my inexperience with IC engine builds. I just set the cutter as best I could at the required angle, knowing it wouldn't be reliably repeatable but hoping for the best. Most importantly, the seat cutter is probably not at quite the same angle as either valve. It never occurred to me ( :facepalm:) to dig out and set-up the compound slide, which is not permanently mounted on a Taig. I haven't tested them yet, but if the valves don't seal after lapping in, I'll go to your method for the next pair, and the seat cutter as well.
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Today's post will cover disappointment, heartache and eventually success!
So, at this point I've made the head and all the bits for it, but based on my Webster experience, I definitely wanted to test it before assembly to the cylinder. So, I needed a test fixture. Here's the first pix of making one. I had a scrap bit of 1.75" OD Al rod, so I chucked that up in my 3J and turned a bit of it 1.50" to match the head diameter and then drilled thru 7/16", tapping size for 1/4" NPT thread, and here I show boring out a .75" ID relief to allow clearance for the valves.
(https://lh3.googleusercontent.com/pw/AM-JKLVGSOcUX7L8zkm-XzbvG1xF_kJjmnrmPP8-7r6K9DN1rLu63mz1b0krgGvBYzcTov62qxWidTcmEFJGfa7NXG-hQhi2cQiVFrblyDUlFPoeLsf19YUNE71UG0Va80PPZ8ybaVnkgf-pwgYK17X8D8Fv=w722-h962-no?authuser=0)
Then over to the mill where I drilled thru 2 holes for some 6-32 studs to secure the fixture to the head and tapped 1/4 NPT as shown here.
(https://lh3.googleusercontent.com/pw/AM-JKLViss0G6pOgheAuzUyfd55JEiF7W5m8ruFs1sdTO1P7p251zfUXmmLEfyryFKaNnzkEeEeUGXjRWBXWWOy7uNgXgSI8o9bkiJ61RNf9jXJCJ2w57bQKDuhKkcwhdWZrgXyvw7UyK-yHO6Cm1VGVWIZa=w722-h962-no?authuser=0)
And here's the test fixture and a air fitting 1/4" NPT x 1/8" barb and the Queen looking on in approval. The seal side of the fixture was lapped briefly with some 400 grit sandpaper on top of a small granite plate.
(https://lh3.googleusercontent.com/pw/AM-JKLV7HKJTuuGjRC_oskxknlnAAcUBsTawc2q2VsCrpkQoWiiIUHuIc0QMm_lrBtpUezIQHlQD_G4ZawTUxcUsLrXQK6pDXvFKHoAYqKJOU_ouocCs8R5xXgpVkn6HSJj4onAnxIhu8gvBpKgFtFxqvxsv=w722-h962-no?authuser=0)
The test fixture assembled ready to go to work. I added a bit of Loctite 567 thread sealing to the threads prior to assembly.
(https://lh3.googleusercontent.com/pw/AM-JKLWtA6Rpo-vIKSFw6X1vCaZjxxqgJ9nKSRD_5d_udRhVxFlX-aSeCj7kg3LAv-KlfO5MPTV394PwpJWeAGVdDCYa-oU2UtzXfstEH_OPrUfQQ5mcIM-5mcCiwFqRvJtH33uyHH0nN-Bu-QIxo-LJNOYn=w722-h962-no?authuser=0)
And here's the entire test setup ready to go. Shop air at 120 psi is coming from the right side via the large air hose and then enters a small regulator then the lower pressure regulated air flows the regulator to the test fixture via the 2 barb fittings and some 1/4" OD clear air hose.
(https://lh3.googleusercontent.com/pw/AM-JKLWyQurDddSJe_sqD9AvrqsO81AS3LOSrWCZtNh0ZEHBWsWr3x6psOBWonjlm6FAT7U9sNP2Zjms7CMcwRCZYdjzFZ17AsS_YZhMH_sotmAXY6UT6rHPdOfdPpZtH9v0M13IfeElz2u0RP6wtV0mFCd5=w722-h962-no?authuser=0)
I perform the test by submerging the head and test figure in a small container of water and watch for any bubbles. I was quite saddened at this point, as the valves appeared to hold, but the little Al blanking plug used to seal the top of the thru hole for the spark plug passage leaked. I'd pressed it in place and used Loctite 638 on it, but evidently that wasn't good enough. In another thread I asked for advise regarding how to repair this and I received some very good advice. So thanks to all that responded on that other thread!
In the end, I managed to press out the existing plug by making a small, close fitting punch and pressing it out. I then used JB Weld and created a much rougher surface by making a new small plug and made some threads on it using a 10-40 die and a ran a 10-40 tap thru the existing hole. This in no way created a good threaded connection but was an excellent way to create a rough surface for both parts. I also made a small head on the new plug just to more easily locate it. Here you can see the head and plug prior to assembly.
(https://lh3.googleusercontent.com/pw/AM-JKLWSB1dYhD48lIdn-NSVfTOh-63z6BT3i1Go1qPpCVWWd9PJPxDi3YeCD-HyGMpDZ-Dlj922c6aKl6cdYNz8V6v4EBC3T9II--gy01YNqwJMLLfemqiV8Y6GEJa1tK11KqKejIJ68QAFlyfihT1elUVw=w722-h962-no?authuser=0)
And here it is after the plug was in place with a liberal coating of JB Weld prior to assembly.
(https://lh3.googleusercontent.com/pw/AM-JKLWYbi4Wi04XFvE7afbASzBE13_s3qL0Wn42Ous1afOW4kZS7QY16xeCuP1XMwjTGumzJCzgpDq_i4CfS_mEnSpMNMOE7AG5juaiu06Kbh48YjiAnU1yj_SGQ56-Cxj6Xl36r5fSG7vG-AZi0Wstd5CO=w722-h962-no?authuser=0)
I waited 24 hours for the JB Weld to cure and then pressure tested it again. This time the plug held, but my intake valve showed a slight leak at 20 psi. So I tore it all apart and relapped the intake only using just a bit of Clover 600 grit paste. Then after assembling it one more time, I was able to get a successful pressure test!! Huzzah!! :whoohoo:
I think pressure testing the head as a separate assembly was a very good thing. I suspect that if I had assembled it without pressure testing it, I'd have gone down a dark, depressing road trying to get the engine to run as I suspect that small leak would have been impossible to spot when attempting to run the engine.
Looking back this adventure with the head, I'd like to offer some advise to any other Upshur engine builders. First, don't drill thru the head to connect the spark plug passage. Just drill from the bottom side of the head and stop when your intersect the hole from the spark plug. Doing it this way totally eliminates the need for a plug. Also, I'd suggest NOT drilling all the way thru the head for the rocker arm post. Drill only down to about .40" and shorten the rocker arm post accordingly. This eliminates another possible leakage point.
I had decided that if I couldn't get this repair done successfully, I was going to make a new head and would relocate the spark plug to the top of the head vs the side. Upshur in fact has an alternative head design that shows this very idea. But the way he designed it, the spark plug hole is only about 50% exposed to the cylinder. The other portion lies outside of the .75" cylinder bore. He did it this way as otherwise the spark plug is hard to get a wrench on. I made CAD model of an alternative design where the spark plug hole was moved a bit and then drilled and tapped at a 15 degree angle to the top surface. This gives sufficient clearance at the top for the plug and moves to the entire spark plug hole diameter to within the cylinder bore area. If anyone is interested in a print of this design, or the CAD model I'd be glad to post it or send it to whoever might be interested.
So, that's it for today!
Enjoy!
MIke
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Hi Mike
Sorry about the problems, but at least it feels better knowing that you have solved them :ThumbsUp:
As I'm sure there are several who would like to see and probably use the revised drawing you did of the head - I wonder if it would be OK to upload it to the drawing section ...?
Best wishes :cheers:
Per
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Hi Mike.
The test fixture I made the other day is almost the same as yours, differing only in minor dimensions. When I get the chance I will follow your lead and do the dunk test. The only unnecessary hole in my head (cylinder head, that is) is the one for the rocker post. The post does have a shoulder, which will help a bit, and I'll goop it up well.
I'll be following your build even more while I can't work on my own! :popcorn:
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Hi Mike
Sorry about the problems, but at least it feels better knowing that you have solved them :ThumbsUp:
As I'm sure there are several who would like to see and probably use the revised drawing you did of the head - I wonder if it would be OK to upload it to the drawing section ...?
Best wishes :cheers:
Per
Per, I don't think I'm comfortable with uploading my revised drawing. Upshur was careful to mark and date his drawings with copyright information and his estate still sells his drawings. I can't see that he actually registered his copyright(s) but I think his intent is clear. I'm not exactly sure of the law in this case, but I certainly want to respect the spirit of his wishes.
I think I can provide enough info for others to replicate what I did with respect to the sparkplug hole with the following info:
- First change: Don't drill thru the head for the rocker arm mounting post. Drill only .40" and shorten the rocker post accordingly.
- Second change: Relocate the spark plug hole to the front using the following information:
- When viewing the 'top' of the head, locate and mark a point at the following x,y coordinates: x=.1875:, y=.3248". Zero is at the head center.
- This will create a starting point 60 degrees from horizonal and .750" from the center of the head.
- Change your setup to locate this point and to be able to create an angled hole at 15 degrees from vertical with the angle toward the center of the head.
- Spot face with a .375" end mill to .25" depth. This creates a flat surface to start drilling from and creates a seal surface for the spark plug.
- Drill thru .221" (#2 drill)
- Tap 1/4-32 to .5" depth (or deep enough to completely accept your chosen spark plug)
And that's it! Hopefully the above is understandable.
FYI.
Mike
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Hi Mike.
The test fixture I made the other day is almost the same as yours, differing only in minor dimensions. When I get the chance I will follow your lead and do the dunk test. The only unnecessary hole in my head (cylinder head, that is) is the one for the rocker post. The post does have a shoulder, which will help a bit, and I'll goop it up well.
I'll be following your build even more while I can't work on my own! :popcorn:
Yes, IMO a test fixture is a necessity. And I very much like submerging the test part in water to check for leaks. Just like with tires and inner tubes, submerging in water will find leaks that are otherwise almost impossible to spot.
On my head, I drilled thru for the rocker post, but it sealed using Loctite, so I was lucky in that respect. But I'd not build another head with sort of potential leak point.
Safe travels and I hope you enjoy your holiday! I'll keep working and I think I'm actually getting fairly close to attempting a startup.
Mike
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Today's post will cover 3 smaller parts for the engine.
First up is the starter hub. This is exactly as per Brian Rupnow's design. I used it on my first I/C engine and it worked fine so I decided to do it again!
I started with a piece of 1.375" round stock, I think it's 12L14 as it cuts so well. I turned the smaller OD to 1" and the larger to 1.25" then drilled and reamed thru for the 5/16" crankshaft. Here I'm boring the larger recess in the end that will accept the starter spud.
(https://lh3.googleusercontent.com/pw/AM-JKLXXTfczwm09EG69qKCqyN4_fraScmA9sAotxgstj0N7aXjBh7NE1v6KraqD-p87geivuV-j2CFd9XQ4H70bDyHIryrveI73Bnf3yIxQ-qxU3BB4tGCMlK--nB7wr_DZSc3SDIbNVtiqe7y61Bt0ODXW=w722-h962-no?authuser=0)
You can see why I left the 1" OD a bit long. I mounted it a collet block, located it and drilled the holes for the 1/8" dowel pins and drilled and tapped 8-32 for the setscrews. The collet block makes indexing the locations easy and setting a stop makes it repeatable in X.
(https://lh3.googleusercontent.com/pw/AM-JKLWrZcfvqle0fF8YuMRQVmc8mY0-JbIf829pqN-LR7drptIUxJjjzFKIqh215IgHSXBG05CbMXOqAXLsVaL2NjUW43x48Rf-GTEKzWKIyRRKs6sMQjbrsTnrcI9TXog3YbY0YpanRBE2AUafqUNvVPWf=w722-h962-no?authuser=0)
Then back over to the lathe to part off the starter hub to length. I used my favorite 2mm carbide parting/grooving tool.
(https://lh3.googleusercontent.com/pw/AM-JKLV2HmPYM4j9Q-MFFpsHdocZjGqitVXURMt_xnaaGiFKlBIg4NeDabxwph5Yg6lXOPXqZ3KSPhi4nRY9Sp8IM31Yu-OlbkCqQk-V2Cv-R_9PMhTmkKuK2e9LnEqueYMQJ67flU6DjCT9aXw1dIAHC3TS=w722-h962-no?authuser=0)
Broaching the 1/8" keyway on the internal bore of the hub. I aligned the keyway to be inline with the 8-32 set screw hole, just by eye but that's plenty close. For the 1/8" broach, two passes are required, one with just the broach and the other with a shim inserted behind the broach. I oiled the broach liberally with some Tap Magic EP-Extra cutting fluid.
(https://lh3.googleusercontent.com/pw/AM-JKLU9er-lfNo1UNRQ9noT-6JYBS0VWqkx80E-V0xXjn0jybiC4gZKuVZXdli_3_mTwbpZpVKCrC2cPFMY6hvGJ862wNtLbNRg-_qGKTOkBXhlIlbW28YrMaSqG8Y0gIrh7_qfIiYYZ-kMQ_GgjZlEYR4v=w722-h962-no?authuser=0)
Here's the finished hub on the print with the 1/8" pins pressed in and the key laid on top of a 20P coin for comparison.
(https://lh3.googleusercontent.com/pw/AM-JKLXAhHXk5HfbUbfjo2djuuOQ4htv201WoYN1eqZQ7rrQWPO_STO6qOFXk_VZoGCn_cRzXyloV7nWpNK_bdaUot3JweydgpiA70ugzXbCtJj6OueLkQiIEJdDMifhRk8172DUBmFlo33cxlWtsmN4nq9q=w722-h962-no?authuser=0)
And finally here's a pix of the starter hub installed on the crankshaft showing the keyways matching and the pins installed.
(https://lh3.googleusercontent.com/pw/AM-JKLXuJ9o9GzHPBzfTNgBL-OE2cQB3cgcQpstgr36gz0fgJmJO_UXmzX5cGb4rOaTL0FotEJoO4MgCHeaHFbLvjOv7REtHa1TsiAtftWjngeCFJiSPEdKyc-n9kOS-nAHXswUglqUopizZj90RG279_NKS=w722-h962-no?authuser=0)
I'm not showing any of the steps for making this, but this is the ignition timing disk. It's a piece of 1" OD Delrin rod, parted off 3/16" thick, drilled thru 5/16" for the crankshaft with a 4-40 drilled and tapped hole from the rim to the center. I drilled a 1/8" hole near the rim and pressed in a 3/16" long magnet to act as the trigger for the hall effect sensor. Shown is test fitting to the crankshaft.
(https://lh3.googleusercontent.com/pw/AM-JKLV2iKeti8ZwnoWP5GdJ8Ml73SFgemle6V6L5ZspCtyJn56waccd0asem8E9wYCnuyviqPskUkPiA-8BOrQMlktQp4DWIE_0elUdC0U4WiU8y4fYGhppAOrsDsUn2auXB6WECZ64HkI0qlq06zSmhkS8=w722-h962-no?authuser=0)
And of course there has to be some way to secure the hall effect sensor ot the engine. I'm using one of Roy Scholl's S/S CDi systems and he supplies a hall effect sensor with a very nice insulated housing that prevents all sort of problems. I very much like to use that setup if there's room for it. Shown is a small bracket made from a bit of scrap Al that will act as the holder for the sensor.
(https://lh3.googleusercontent.com/pw/AM-JKLV3T5fxeB3Qr1UqM0Ju03r809x3m7hSE8KYPFLeiwwJjV96ptn_fwqS2tmZvkkfAKnztnVIh2mVLAvxqFj56W-vAePlKzbLenK4xXopwLkh1DvOJcaEgh9HT7Yoy2jhBdSf1ow0Xrz3lHmjK9mPuEta=w722-h962-no?authuser=0)
And here's how it looks mounted on the engine with the ignition timing disk installed.
(https://lh3.googleusercontent.com/pw/AM-JKLUvAMGfpt4Yxg2T4GvShi5F-gG72x7G3fG-VvLLL-dNNFCYxzq_OJ_BPoHqagcGfKh7TcWQaQILKPVrskzzUKC2v57gc9zuXVOBz9CN7qwWbN9lTlU9dV2n0SSwdqiY_eXOZoheoZNWiYOPhFtIMPl4=w722-h962-no?authuser=0)
And that's it for today.
Enjoy!
Mike
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The next part(s) up are the flywheels. I tend to like to use cast flywheels and I purchased qty 2 from Martin Model and Pattern from Scappoose, Oregon. I chose the 4 1/4" six spoke castings that I think Gary Martin calls a 'heavy pattern'. These are a bit larger than Upshur calls for, but I figured a bit heavier wouldn't hurt anything.
I'll only show the work on one flywheel as they're identical. One thing about these flywheels castings is that they are extremely high quality with plenty of extra material on them and with almost no noticeable inclusions. Plus they turned to to machine very nicely!
Here's the start of the machining. I mounted the casting by the rim and tried to get the interior surfaces to run as true as possible. I gripped the casting so that I could get to just a little more than 1/2 of the outer rim. Here's the casting with 1/2 the OD just about finished. I used a standard ccmt insert and that worked very well.
(https://lh3.googleusercontent.com/pw/AM-JKLXwNJzc4U2qkDxO97EMeaIkWMqrta_J06gG6y1YwrmXLoH3xl5rD4ObHbQP473aQeXltZg64PvBJ478OagDk_36IldXPndBBN20lkF3c0X5ACdJozgYDQxHnsa9EsJ4fSqtnHWULVQbegnVIzHaUN6w=w726-h967-no?authuser=1)
And here I turned the casting around in order to machine the other half the OD. I used a DTI to reach the machined surface as best I could. I also made sure that just machine side was running as parallel as possible by spacing it off the vise jaws with a piece of .250 tool steel.
(https://lh3.googleusercontent.com/pw/AM-JKLXKTnM5DvXSJEM3OZVtc0kSzXBgDW-fvP9WEZm00znU3Nh92oUly4hkpYO6akxhgRz3PyF_U6kRWUYQ1bjl0ue9oxc2dLviEJp0z8gISMilNKWaa45MmGZOCjav7dDvViUBrByq6uCylLtK-aDAjcI4=w726-h967-no?authuser=1)
Here's the start of machining on the 2nd half of the OD.
(https://lh3.googleusercontent.com/pw/AM-JKLUlX62Dszfx0ZoOuoKl5B-CoW8MddAPiUVmG4Fzlwbf6E1qNGtgNlP-vJGenXgb1it6L3peYh2dCbhIxj4nRiqGQZgLs4Os8xB-GtqMIRgZ1rF5bImQ-7JuuXcTaTuOh_9jtpmS-SQePuZ0-vdR23tl=w726-h967-no?authuser=1)
And here's the casting showing the various features on the side being finished. I turned down the OD of the hub and flattened the end of the hub also. I then machined the 'side' of the flywheel just enough to remove any casting roughness. For this I used a 3mm carbide tool as I wanted to make sure I left a small radius at the various corners.
(https://lh3.googleusercontent.com/pw/AM-JKLVHubqcdzh3ikWJI2r9OxSksbPvQK8aOyXnpQp7l31cvjlI1FpqKBcM4tGVe6NzGurQfNqgHDpIdnxR2vDNpqSp6vrP8Q8fT--nMXpiDlhRtFKrjlYDGdg57YNx8vWRzNJU9UwNVoWvyjRkHd7vkR7d=w726-h967-no?authuser=1)
Then I changed to the 3 jaw chuck, just since it's faster and I was dealing with 2 castings, and drilled and reamed the center hole to 5/16".
(https://lh3.googleusercontent.com/pw/AM-JKLVrR_HL6ND6DGqFrrrLncNaFGbw0A2iUn-FcTKeKEk5SV95CxN65_UFqqEc_uN1mjpGz9lheELKWYYqyqMw_rKF-YM3Fc5M3pMgUY5bndsK0GaV2NaWOTZX1jWAjORTCPCjUtBTRwWsns-l0MJrfrzl=w726-h967-no?authuser=1)
And here are the 2 flywheels test fitting on the engine. I ended up taking down the OD to 4 1/8" just to make sure that I don't have any interference with the wood base this engine will be mounted on at some point. Note that the very, very small difference on the OD can be seen, but I'll soon take care of that. But the flywheels both fit well on the crankshaft and seemed to be quite true.
(https://lh3.googleusercontent.com/pw/AM-JKLXNHhFvh5hmhJEKiFkw9JmTCi7HwAEaAAb0uqPTRUZ8YOU5nKflDe95F1Ewl50EwlhwKfUyIxpvUxMQxj3_mH3A1IEMSB2x-cXG-c7Ivxekyfy7I4fpXI-_UX4W3T0xwj_aWvX0YfGd4eL1kdb9UMPs=w726-h967-no?authuser=1)
I made a couple of 5/16" temporary shafts to mount the flywheels for their final touch up. These are just 2 pieces of 5/16" drill rod with center holes drilled on each end. I secured the temporary shaft with a bit of Loctite 638 and let them cure overnight. You can clearly see the OD differences on this pix.
(https://lh3.googleusercontent.com/pw/AM-JKLXQxz_7aMf_0jOntCLaMbn5KYw7s4esj4nBIMVukeO0174YdSaBBr164ZNoJDmvnC-S5xNzsZppNck4Sp6Qvo6ND3HVmmXCfHynX3BGolac6Dd8TzmDHvEwOfQ5XBGKDruKhiR6uXyBCv3DiLUPfXdF=w726-h967-no?authuser=1)
I mounted each flywheel in the lathe, using a collet on the drive side and a live center in the other side. Each of the flywheels ran very true. I took a very, very small skim cut just on the OD to eliminate the very small difference between the two halves. They sides were running completely true so I didn't touch them.
(https://lh3.googleusercontent.com/pw/AM-JKLUkPVj-Iz5V_EiaaA2x-c_uRnHEEIAhP-l2wIK7lfH0J76EU-8EsbrC3XwY2liyWFGbVReDR5_6X2eeyp7aWKtc0f53dHt1ZGz36gfcFJLA-V2BfsqlzrC1gCtbA5jSIjhxrKgN1RKSuhGa4zBcOTyE=w726-h967-no?authuser=1)
Here's the pix after one flywheel was touched up on the lathe as compared to the one that hasn't yet been finished off.
(https://lh3.googleusercontent.com/pw/AM-JKLWjC8kbuY-1zPnCmPz33f2byarbGEgQWFGhZqGtCJXL2dotMWTDJdYEXHeU-Rlj8QerB4qSNg_Sz9am5DJe7k5p3428tQXz0WTUadnIgIA72gN47xJajXAig4pSgzPOPca8grpAhVWfZASdfOnuhY20=w726-h967-no?authuser=1)
I wanted to add a key and setscrew to secure the flywheels to the crankshaft. I ended up purchasing a 8-32 extended (pulley) tap and a #29 aircraft drill from McMaster-Carr. I ended up tilting the flywheel by 5 degrees in order to place the hole as close as possible to the middle of the exposed hub area. The best way I found to do this was to leave the temporary shaft in a collet block and then place the block in the mill vise with a 5 degree block under the collet block. Shown here is spotting the hole with an extended center drill. I pecked away slowly at it and the drill did stay on center.
(https://lh3.googleusercontent.com/pw/AM-JKLWHjZTDUnTU0auucdOzMCjaBEPWV3nxThZ-zYcAA4860hdccmfYXN5ley30QHnDgXL4hIjG5cRVLQ1p662i3CT60IAwxuf70xGYmWLNs7Pxhr33wWPoIgzG4jKKU_2owbUgYP3IzahFDdhTF-oCE9R6=w726-h967-no?authuser=1)
Here's a view of the overall setup. I quicked the mill out of gear turned the tap while held in the chuck. That worked well especially since the cast iron cuts so freely.
(https://lh3.googleusercontent.com/pw/AM-JKLUVgRz3dN24hea_P6mrWyXZBzdzYFR7wjMKTtYCflGxU6AcDV0aNQEhz8TjFJnHzdWXBNBAN98fuKnyUVLMUTCF1fo_NFQkPQ6PGX0JhKfQ2xL2OkmtD7sXQ8Kw6zYtlb1WD5MQFErHBBB07Frze-lW=w726-h967-no?authuser=1)
I don't have any pix of broaching the keyways, but I used a standard 1/8" broach driven by my Dake press. The 1/8" broach needs 2 passes, one without a shim and the 2nd pass with the shim included with the broach. Shown a pix of both flywheels after the temporary shafts were removed and the broaching operation was finished. You can see the slight surface discoloring from heating the flywheels to break the Loctite bond in order to remove the temporary shafts. And you can see where I drilled into the temporary shafts so that the hole through the flywheel hub was full size all the way through it.
(https://lh3.googleusercontent.com/pw/AM-JKLX8FdSRIJsqGAAW_57BnVYmd-wmL4LnUOdvaU9d_0HbDloH3AYxxXlVhV10GsCnAhI6EAxF-WiLuPNC3ad7RbbffdsI4r5Lck8Kc6f9TJ3REvs2Byz-pUDkkqrfY-bZWvQEPvLdOyEvqyN0AENb-ssg=w726-h967-no?authuser=1)
As a bonus bit of information, I'll offer the following which probably everyone other myself already knows!! When making keyways, the keyway portion on the shaft needs to be actually milled slightly deeper than I originally thought. When I made the crankshaft, I found the top of the shaft and then plunged in .062, essentially 1/2 of the key size. It turns out that the cut is measured from the 'full chord' point that's equal to the size of the key, so in this case, a chord of .125" and this is known as the "M" value. There are complete formulas to calculate this number as well as approximations and of course The Machinery Handbook discussed this but doesn't have a table that extends to very small shaft.
The approximate value can easily be calculated by squaring the key width and dividing that by 4 times the shaft diameter. That gives a value of 0125" vs .013" for the exact formula.
So, I ended up filing down my keys by .013" in order to get them to fit. What I SHOULD have done was to touch off the top and then plunge in Z by .063 + .013 = .076". Or do as others might: Start plunging in until the edges of the cutter fully engage the material and then from that point, plunge in 1/2 the size of the key.
That's it for today.
Enjoy!
Mike
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I'm now down to the last major item to build for this engine: the carburetor. I spent a considerable amount of time trying to learn the basics of carburetion for small model engines and what the alternatives are. In the end, I decided to attempt to build the carb first documented by Chuck Fellows, with well documented builds by Brian Rupnow and Andrew Wakefield and I'm sure others as well. I liked this carb as it seemed relatively simple to build and it offers a throttle option. I did end up building a 3d CAD model of this carb for my version of this engine and generated 2d drawing which I used to build the engine.
So to start I milled a small piece of Al to the required dimensions for the body of the carb and then spotted the off-center hole on the body using the mill. I drilled a small center hole at the spec'd location and moved to the lathe.
(https://lh3.googleusercontent.com/pw/AM-JKLUjQeNlhagazr9dwo2MuK2lDSI-Qs7Mw3jYEKrW9TK2FQXoTBQhSc5glTTyFoMInftU6BG6w44fZ7iJph3dvDV3AoK_YIwwP1sQQ3s3CquS2YSRu2iVsuId31l9WP5bVXl4THnKDDaY6mR03I1yC7Dy=w677-h902-no?authuser=0)
On the lathe, I put my spring loaded centering rod in the tail stock and then used a dial indicator to center the rod which in turn puts the to be drilled hole in the correct location. As you can see, I used my 4J chuck and had to use some thicker packing under the jaws in order to actually grip the material. My 4J is an 8" model and that's really too big for this sort of work, but I did manage it. One of these days I'd like to get a 4" or 5' 4J for work like this.
(https://lh3.googleusercontent.com/pw/AM-JKLXwNTQxu1kjmXWRQJOZizQ9naXmJlA42rDGuU-QMeBOZoau3KYB9GYXPTtjKA12wFaSfjWX4u2-2g5AyBMZI5NpDJjiW0eo29JplsJP8ZNUTx8TC2uHF14UjTQagzhhULDw395p_YhSvHfF0zBwtrml=w677-h902-no?authuser=0)
Then drilling thru at the just located point.
(https://lh3.googleusercontent.com/pw/AM-JKLWGIttSRQR_kf4thYJmmgCMXKSQ2lIA8ycWu6Anjl9-f_UORpT5VLvN6YFCaZAVC_JStmCvDVCUv6ezcyWZhkejLIstsWyLWUXZGilmm_HNwOUA2vsov9mL9JfaVLFggLCWA5lcv_4NH2rJwEIrmQEl=w677-h902-no?authuser=0)
Then turning down the OD to round. This is on the intake end of the carb.
(https://lh3.googleusercontent.com/pw/AM-JKLUQ4okXXdO3AHDFOWN7o4aZ7SH7M_3sBD2M_zZgKSUQLZ8-htw-10LS-1QCmxVy5TplICQ7F0sqzLjQRwBPlrq43S94A6ybpR7L0T1MruomL4Mqbl3-kdc7MqMzNKVlOsw7OPFjfKJ10I-5HFV57pdW=w1203-h902-no?authuser=0)
Then, I changed the 4J back to the collet setup and turning down the outlet end to .25"
(https://lh3.googleusercontent.com/pw/AM-JKLXI8Pyp4zdm-IrzYkQRbGaupddFB4Q0A2kwUSzQZVuKzlSYGzQDIghVl6mBc3nP12MFSliphNY-PIXyhP62eS4N3aHIZWM0iIJT62cJxjlS1CPBnxHbU0Tm2G3Jf4-1POhKA_seyOkqEiL4lJd8ut1P=w677-h902-no?authuser=0)
Threading the outlet side 1/4-32 with my tailstock mounted die holder. Rather than using a slip fit and Loctite, I decided to thread all the ports on the head the same as the spark plug since I have the 1/4-32 tap and die on hand. On the Webster I build, I noticed that the Loctite wouldn't necessarily hold well when the head got hot.
(https://lh3.googleusercontent.com/pw/AM-JKLUmsQeYKqo-VkVAqyMbWehPT2uPLq4EjEJRRsvXShFh4MRB8K8UTC1xFVvku6Wf6BKi0OWGZF-cfrDjN6Klhj9AMCUETChyDwNVZj8Si1j4_IN7qTyx7OimnQmLUpmeK2c2prHjwuoPqLAq-ZkX2TOV=w677-h902-no?authuser=0)
Next I moved back to the mill and drilled thru the body as called out on the drawings and also tapped 10-32 in what will become the throttle hole. Here's the body with the work completed on it as compared with the print.
(https://lh3.googleusercontent.com/pw/AM-JKLW40Jfx9EnSVnYKa6M595IGRA84II0kSHMjqfJAmLDVh4snp0H9d_p0z6EmfKJxf2uo1RL0Xh8bIv52QsbNU5EqH7ThoaoriMC1AVhAQcYSuBxtqS-xz-uqe0SODFk48hRTu3HZeYKb0eNia48vb_t0Qg=w677-h902-no?authuser=0)
Next part to be made was the jet. I started with a piece of 3/8" hex brass stock and turned the first end down and then drilled .052" to start forming the jet. I was careful as this hole has to be drilled to .625" so i was careful to clear the chips often while drilling. Shown is the drilling operation with a 20P coin for size comparison.
(https://lh3.googleusercontent.com/pw/AM-JKLW1PobXJfbwxiiNxzoZWG-HLIHGxdhjNacVmLQ7uSBWoZzekdd46tBNrHDm1oQju7sx12LVJj60RdPg4SVM6QrdwPKskWEtNzu2_U_5Yapq_etd9D24uZ6rRhwm1UvY9olqpm-r9P6MMKR5zmOO2lpARA=w677-h902-no?authuser=0)
Threading 8-32 on the longer end of the jet. This was done with my tail stock die holder and rotating the holder by hand.
(https://lh3.googleusercontent.com/pw/AM-JKLWIVW7LH2sPpn2KXcks1M4makG8iXzbhg_nNl_0hsRha0RZQg8F8i4XdR-O7aiXRLAvyg_wDoeh6pv2woEUpBEodfE4VOKYWW4CckriDag9qxnnio5BPXKGWXrERFBwyXyL7bHQdcMrlobC73cCf4x_yQ=w677-h902-no?authuser=0)
Back over the mill with the jet held in a collet block. After finding center of the block and the end of the part, shown is drilling a .040" hole thru the side of the jet, being careful NOT to drill into the other side of the ID. The Queen is observing the operation.
(https://lh3.googleusercontent.com/pw/AM-JKLXMWp2hbizL-P1kIX-u7x-6bNfx03cWhE2fJ6svBnPbpMIX84mwaCvpMRhbuDxK4kjU-Om7wKyv1QB7woH0Y6aVfxLxjz9u7jzoLNdT4z0Y5VtwwTEBo0FqCNPn1QAn9yXpO_N7AP6KgmKvCw7nkzegmA=w677-h902-no?authuser=0)
Back to the lathe, holding the part in a collet by the just finished end and turning down the opposite end to .125" OD. This is what becomes the fuel input port.
(https://lh3.googleusercontent.com/pw/AM-JKLXo_Memz3kIm3P8Ps0IY9Z5NDAFqo8yOi0RTMhIQO6H4W7agRlTuXlINEjNJu4_d9dDDlLwpW9OKYWTPI4mHTM2vuaHmfaTf1ohZpYRFKzytvZ3yzcOSrG4b1hIkiZqrgztWlosO6bgKzWcEZ-ktc1v9g=w677-h902-no?authuser=0)
After drilling the initial .063" hole, shown is shown drilling thru the remaining material in the jet with an .040" drill. The 20P coin is there for size comparison.
(https://lh3.googleusercontent.com/pw/AM-JKLUn8j4On3xeD8rOLjMqrp5E7hgyUgLTaaPr7TIWuqekdvyN9fq0zr5kgsNjTm7RMKGevsBp4ZZEw8r4DEj2iiUwbJ7AL2GtvLCRIu9VlkXFso13mKaLt02uFExEK1nc_0lrGgn-kouh2Te6KILolRt4TQ=w677-h902-no?authuser=0)
And here's the jet after it was finished laid on the drawing.
(https://lh3.googleusercontent.com/pw/AM-JKLVUHdSOSFiH6HZdWe3spv0jaKpEFRCrXdt-VSTskiavWkfuJh9aMxQqhyekZEM0B1PlfMWI6ifommNReRI_go2U8fEFG1u2AQjXVCQ5De53FnOVY69E4hPQo2NM9WQai2HGHTc05wI003xzSlR4E5Sc9g=w677-h902-no?authuser=0)
The next part to be built is the needle assembly. The first problem I ran into was that I had no idea what a '#18 darning needle' was. So I went over to a local sewing store and ask the question. They came up with 2 items, both packages only about $2 so I bought them both, just in case. On the left is what is known as a '#18 chenille needle' and on the right is a '#18 darning needle'. It turns out they are both the same diameter that being .049" to .050" and the #18 refers to AWG. As you can see the differences are the overall length and the eye, but either works fine to make a carb needle from. Hopefully this info helps someone out!
(https://lh3.googleusercontent.com/pw/AM-JKLWROd-Fg_ASju3w6Al0D-AgPE_0hYZziDe2V4TdXPmmTOPMMIEa8eZ-wHT2QkddmiS99jEJ91oMnMqXBrHcJOWZMo-z5lVsgwprtyvSYV7n9HyLEwWIy0rG40YitEOnRZk8UDQ_HAc71yJ2x19Vd2QMFw=w1203-h902-no?authuser=0)
Shown is how the needle fits within the jet. It seemed like it fit properly so I decided to proceed with what I had.
(https://lh3.googleusercontent.com/pw/AM-JKLULAi7uRXzLnkDZ2eJSJXJcuciM3bnIgo4T-8RIXzYAHIctNO0R5H8DytmE034PtORHYcs3x0o1OUSY7V8TbHiscVrqouCFLov8PE3cHoaZuuGrOT7_v7REyaIALsxEKoE0fLDJW8gW2yAQj4R9JywI6A=w677-h902-no?authuser=0)
I knurled a short piece of 3/8" brass just to give the needle adjuster just a bit of grip.
(https://lh3.googleusercontent.com/pw/AM-JKLU3QNovZv95uzAjdOMOC5Gca5d-kNJ_VQiWuMMMkJScQ9480DZNosh0_8IzUJcYH6_6-sEhVMNBLL-gGxxWfjbN1qlNDoLtHHxK7qR7GOdcizavXI_BSwPn35klyR6iujKEz8ngWHNBuX7eqgPxNNXqxg=w677-h902-no?authuser=0)
Next was turning down the small end to .22" and parting off the adjuster.
(https://lh3.googleusercontent.com/pw/AM-JKLXKNjK4EhUYkUUi5KPoXudODW6aoke-CF4b8Z1p1IxfeXf3E59XJsKFXtnZlBXnWkiyYhALtTnKGBp6aLcqthwq_zKogcqcs5gJC-GjMTOVSvJ4SAxaxscwPvs0Y1NOTMcR0pQezK4aUDPIi9yZoYPhug=w677-h902-no?authuser=0)
I didn't show the lathe operations, but they were pretty simple, just drilling and tapping from one side, then turning the part around and drilling thru for the needle. Shown is the finished part on the print, and you can see where I needed to hand-correct a mistake I made when doing the CAD model.
(https://lh3.googleusercontent.com/pw/AM-JKLU1FPFh0A5o48IPqMJq5Nva-N4d6tGz3CwRG6mwWkW3XNMO-EZJQHEUSoJS3xhBwftE3hOS-RTlexGe-CZCHg-WE3oF8tNnc0yTblfg4f_XgG7s_cYlpgtHcdozKjy_GgJ0ziPNZAlh3WvYdgWTSMRZdg=w677-h902-no?authuser=0)
Here's the needle after cutting it to length, ready to be soldering into the adjuster. I used Harris lead-free plumber's solder. This is the stuff with 4% silver content that melts at a low temp, typically about 430F or so. I find it quite easy to work with. I also used the matching Harris flux. The needle is gently inserted as deep as it can go into the jet and the adjuster is backed out about 2 full turn. Both parts had flux applied and a very small piece of solder was laid right in the center of the adjuster where the needle passes thru it. I made a very small countersink on the hole in order to give a place for the solder to flow to. A small plumber's torch was used to apply heat.
(https://lh3.googleusercontent.com/pw/AM-JKLVm24xS0PqxzO7SUZeUAd8M-ex0UWnqVr8bC5w-kMhTnkUJ9DGWL5fAejn64YEo_gEwuwfUZRWTHs4SGgYY05vb89mzXxd7Dhp_TkU3AbsxowruBXNF5ODPPp0sMynicadn1j5I_aFTk0wP0Joo3GG6xQ=w677-h902-no?authuser=0)
And finally here's the finished carb on top of a 123 block. I ended up NOT using the slits on the adjuster to apply tension, but made an additional spring to apply tension to it. The issue I had when I tried to use the slits for tension is that they simply didn't' work all that smoothly and tended to bind at different point on the thread. I made both of the springs from .022" music wire using one of my spring winding mandrels. I have enough experience making springs now that I find it fairly easy.
(https://lh3.googleusercontent.com/pw/AM-JKLXNP7OzYxDdzMBeW-QOLA09NODC_cU3imKCkTMlZVBET1Y_CuolDK1octzeuC6TpbWMo0_EM7N0_2AaYUjrBjB81ZpWjyLBeJ7dZ-izEgwvKLEvZ_RMb6C0Dy0Ho6EQBWxNZGI1HySJFHcy8SJzR_h86A=w1203-h902-no?authuser=0)
So now all the major parts are finished! Nothing left to do but to do the final assembly and then try to start it up!
All for now.
Enjoy!
Mike
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Nothing left to do but to do the final assembly and then try to start it up!
Great Mike! Looking forward to your first pop! :ThumbsUp:
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Me too ...!
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Hello Mike, I have enjoyed watching your build of this engine, as I have built several of them, one of which I have posted on my You Tube channel. I, also, made several changes similar to yours, and had the pleasure to have exhibited with Mr. Upshur for a few years where I talked with him about his designs. He deliberately designed these engines to be slow runners with a compression ratio of about 5:1 hence the .312 clearance at TDC. I noticed your flywheels are a little larger than designed. This may contribute to a slow running engine also. My flywheels are bronze and machined to the design. They each have a mass of around 17.5 oz., and my engines run about 350 - 400 RPM. I hope you have it running soon.
Earl
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Eagerly awaiting the video of it running Mike.
-Bob
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Gents, thanks very much for following along with this build. Just for reference my flywheels are from Martin Model and ended up 4 1/8" OD and weight about 19 oz each. Hopefully using these flywheels was a good decision and I'll end up with a running engine!
Mike.
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This post will cover the final assembly of the engine.
I tore the cylinder off and installed a viton o-ring on the piston and then reassembled the cylinder to the frame. I knew I had interference between the rocker arm post and the 6-32 nuts, so I made some model scale nuts and washers. This took a bit too much time as I had to make a bit of hex stock out of round as I didn't have the correct hex stock on hand. But in the end, here's what I ended up with as compared to the standard 6-32 nuts and washers. The model scale fasteners are smaller in diameter but are considerably taller than the standard fasteners.
(https://lh3.googleusercontent.com/pw/AM-JKLWLFmcrvbaFTj3e-HoeA3Kf8BkHiNii23axdJty7pTkrgZJOLkdLtD6KIQlGN_0xNrhnaKWNLkgHreV6-QJnaOuPwkvFBlIEzrUhstxxqpW7IwMo0etviCD8sCJGjKANRvRZ3vKxhRcbQoEga-ocrPV=w724-h965-no?authuser=0)
Here the head is refitted to the cylinder with the new model scale fasteners. They fit correctly and looked good to my eye.
(https://lh3.googleusercontent.com/pw/AM-JKLVTWocVKvSv6tLCv0vZC-nAI44kjsAKOut4faM-bZ6aR-U0Yu4CoXs9bOkF0V3-a8y2CgB-kpobLIabejVdb4Vzii0kyXCOWywDJQ2TQJwww6DFN-sCgJJvIPFeyuqVEo8FtA1Qc5iIxbQimjdu1Tl5=w724-h965-no?authuser=0)
Here's the head fully assembled on the engine. I spent a considerable amount of time making sure that there was no binding anywhere in the valve train. I also modified the rock arm just a bit, filing and grinding a better radius on the bit that touches the top of the exhaust valve so its action was as smooth as possible.
(https://lh3.googleusercontent.com/pw/AM-JKLV3L__KdK8IOszgbdCS_-0TDp_Jdo8_EonGSNmhMw1RC9mn6GjgnVHx4WyEZFvKZVEBVfrSTG9wgsZOWaMILrObtSO8AoSzWhukvskr6JsXoJaHdG9Lq4y7vnJlzh3B0KiTW9Xc9PRTZ5PeoYMrjnILCA=w724-h965-no?authuser=0)
Here I have the engine on my welding table, secured temporarily to a scrap bit of 2x4 lumber using some very crude toe clamps that allowed me to screw it to the 2x4 with a couple of deck screws. You can also see the spark plug is removed and is clip leaded to the S/S ignition system. I wanted to make sure that I had proper spark and I also set the timing to be right at or slightly before TDC. The LED timing light on the S/S ignition module makes timing very easy to set.
(https://lh3.googleusercontent.com/pw/AM-JKLWiXnuoBDd-qNrh9p3DXWOD8Kr-eqxh-JOQrkwnpYB2FnUuZBYNJGrIcE2oiVysfH-iwa_x7Iihh5Yr9hpZ25RrJxNfX0VEmazfvXSxxIZ67pR645xpQCRbppPJpjcZaeus6m1TdG3R8JTFxKo2z7Jfdw=w1287-h965-no?authuser=0)
Here's the S/S ignition system all rigged up and ready to go. I'm using some rechargeable NiMH AA batteries and the seems to last a long time when running the engine.
(https://lh3.googleusercontent.com/pw/AM-JKLVzNQfJBGq-wYsgPDFUzl39tUUZLpCbgbIxubcjc0jJLp-_4KYOmeloaLtqdMWwLqn4B0JrTRPSqYDiRN9eGc_bVjKzTUg__zyfUJ-6gK2L6F34vKSPWUWhzA67hSxKXSVnfBXzUe_PAtvbGdONKc-Plw=w1287-h965-no?authuser=0)
And as they say, 'that's that!' Nothing left to do but try to start it up. So after a bit of time spent varying ignition and exhaust timing all over the place with no joy, I noted that I couldn't see any movement on the intake valve nor could I hear that 'snorting' sound that some describe. So I thought that the intake valve spring might be too strong. So after quite an adventure of removing the existing spring, losing somewhere on the shop floor and making a new one and shortening it by 1 coil, I got this to occur:
https://www.youtube.com/watch?v=5_hhxoa1hRo
I then played with the carb setting quite a bit and managed to get another run with the carb throttle set to run about as slow as I could manage to get it to run.
https://www.youtube.com/watch?v=XDS8Rb1_fNA
Notice that I'm just using a fuel tank from a hobby R/C plane for now. The fuel I'm using is some Echo brand 50:1 pre-mixed gasoline. This is the stuff that comes in a 1 liter container and is said to be ethanol free. I also noticed that the carb is quite sensitive to the needle adjuster position and it seems to need adjustment as the engine warms up and as I varied the rpm. I think I had it open only about 1/4 turn when the engine was warm.
That's it for now!! I'm now starting to work on the hit-n-miss parts and will post the progress of that work as it occurs and hopefully will have a better video of the engine running in h-n-m mode! I also will make a better wooden base and put some sort of a plaque on the base.
Enjoy!
Mike
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Mike-
Nice! Congratulations, it is always a great feeling when they come to life. Well done.
-Bob
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Excellent! She runs! :ThumbsUp:
And your cute little carb seems to work just great!
Kim
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Sounds and runs fine - you should be happy with the result :cheers:
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Well done, Mike. A great result.
MJM460
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Congratulations Mike! Excellent work all around. :ThumbsUp: :cheers:
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Congratulations on a sweet running engine. Earl
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Very nice and congratulations!
I love that your flywheels don't wobble! I personally hate that.
Are you going to enclose the SS ignition in the model, or have it to share on other engines?
I've included one ignition to an engine. That can get expensive, but makes for a cleaner looking build in the long run.
Also, I've used rechargeable batts with a charging port so that I don't have to tear the base apart to change batteries.
Sid
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What a cutie little engine and runs a treat. Awesome results Mike and ………..I…………likeeeeeeee…. :Love:
:cheers:
Don
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To everyone that's taken a look at the build so far and made comments: I really, really appreciate it! It make all the work worthwhile!
I've taken a few days away from the shop but then jumped back in and made the hit-n-miss parts so I'll start documenting that now in the next post.
Again, thanks to all for your extremely positive comments!
Mike
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So when we left off this engine's build process, I'd managed to get the engine running sans hit-n-miss (hnm) mechanism. One of the main reasons that I wanted to build this engine was to learn how hnm mechanisms work and how to build them. So, I'll document building the individual bits in this post. I may break up the post if this gets too long.
First up, I wound some lengths of spring for the hnm mechanism. That's .014" music wire wound on a mandrel in the lathe set to 72 tpi and running as slow as my lathe would go, about 90 rpm. I've shown my guide setup earlier so I would repeat that here. The shorter spring was about 6' of wire and the longer one was about 8' of wire.
(https://lh3.googleusercontent.com/pw/AM-JKLW8gRSeZqeV_0s443HToq6lJ2Y5oi2VqiGKasN9Fy55Qq4tNJH-rcEJ_u3UbwP1roKvWaY_s88-bn9IiPppZ1tJX3p8klq7MndTDZTSrjB9EY7_-oaescBs9dLILIbDMuxK_0wj6OjMulv8ewGeXuxrbw=w724-h965-no?authuser=0)
Here are the brass hnm weights made from some .25" brass bar stock. Just basic turning ops in the lathe so I didn't bother to show that. I made a reduced 'head and neck' area to be able to easily install the springs and so that they would stay in place once installed.
(https://lh3.googleusercontent.com/pw/AM-JKLWrpndDlX8eLMzeM4DEyTpIh_O053RRc4Yo2LJr44dSzH-GAIvbvjb8yoci-eWu-67uv4p1k9IuCnBaHg-o9JnT_DpWQz1lNGPwZuChRK2GZrQl15QwSXpDaK_-nIS1ymvKTEGTgWhzbTuueaQvAlQJWA=w724-h965-no?authuser=0)
Here's a couple of 2-56 studs just cut from a piece of threaded rod I had on hand. I just used a bench grinder to slightly round the ends so that the threads would start.
(https://lh3.googleusercontent.com/pw/AM-JKLXKUhAdr3jOoqmDZKFBb0q7KPHZMGyybJ5ZOhp1ZwcY0Xd2V7KLeV-hyNTIN_0f87z5Rg13K-vLFoMXBfw5IzcLStwuP8M8kbfyA339bfRh0WAyJnppicvta5zaeGBOk0CEpfdFoXv7AINsxub7KOA1_A=w724-h965-no?authuser=0)
And here are the weights and studs fitted together just to make sure that they'd go together.
(https://lh3.googleusercontent.com/pw/AM-JKLXFsgWkKRMKjFnCqIPUpDqX7nc3nj7OTRli0t9ou3b9FAr4GY3eYVtXrPPihh4tI7TaIjfNBraBnclYMqTFhSHJdyp811pdDYL27SRn2oBpEexb6AqSa6WGqQFlIcQ5L4eM6w0gwfp0A1b4NjHyI1wPXQ=w724-h965-no?authuser=0)
Next are the hnm arms. I started by bringing a block of steel to the largest outside dimensions, locating the edges and then drilling the holes for the pivot and weight attachment point fairly deep into the block as shown.
(https://lh3.googleusercontent.com/pw/AM-JKLUQHv0EuQHlh09I_WjQpmnpzV6qNaQ7Rg7ZTvQv4h3oASHsr9rLEHSkl8wmkICYOLkLfu506_Jr340LnZgASgm9B8z_fwPSW16WVMqqbSN7Sij4deR1oEDYY6XJ7seRmodLyg5xpJSEsISRhrffVbcAnw=w724-h965-no?authuser=0)
Next I turned the block as shown and using a 1/2" end mill created the features for the arms. This was just a couple of passes down the middle and making one side a bit shorter for the arms.
(https://lh3.googleusercontent.com/pw/AM-JKLWIKLLkLuY0YfQoNUYnDn4FzifzofEtldFh2W1JVqsFCwO6oTELLwjQHqZSUDpCG8u2ReNJDsRCu-7ZiQwmTVun3xCVyDGeixsazi2SeQfaDgTU_jS-6EIGeQgNq4aw8HegV-RDfL3fNYzfFGQShVWo9g=w724-h965-no?authuser=0)
And here you can see my general approach with the in-progress block on top of the drawing.
(https://lh3.googleusercontent.com/pw/AM-JKLXTPzCG1HjySI-r9uMGwDahamfRXtQdD6v7hpNw2_84CQx9a2pSLi_7QzgcPFYvXPBciKMxynz6KiMKwxcb5hzimVHBlJP0R6hoFpadz7QXyubAlgJbfHhxJFKlveGKgC3QYq3ns-0jv_GXg-dCzELH4g=w724-h965-no?authuser=0)
And finally we see the arms emerging! One of my favorite operations, using a slitting saw! I think that was a .035" saw. I just located the top of the part to the top of the blade and then lowered it by the width of the arm and made the cut 2x times.
(https://lh3.googleusercontent.com/pw/AM-JKLWo8U2TXu2WOhEhzrMtiH-rc4YHeQsy2DUvI4hcc9S_G3zn3Clg_W9z1kzAH2RAwD_z1mkjdKS6dvqEfI0ObpRzphDuD67wy0FE4JwrQe3Go3M7Q5NwHS8QDlhLeoVifsEhIBCdS1trWts6SeuG5VspcQ=w724-h965-no?authuser=0)
The arms finished against the print, except for rounding the ends of the bits that engage the hnm spool. I do that in a bit on the belt sander.
(https://lh3.googleusercontent.com/pw/AM-JKLWbvaIUTkwfUCNmh_sjpAwdyNrwGM1nYnumC4tcJFzykE1xmo6vlKdyJaPZM5cYbxRXiCtlg1FakCbLdPEETCo9lF_DVzkccsLAvaUytWl3_NE8sclUvWzBHa8Xi7ye8wtxKnMlEg54ZHzrqLy6xXybgg=w724-h965-no?authuser=0)
And here's the general arrangement of how the hnm parts will go together. I made the spool earlier in the build thread and it's different than Upshur's original design. As you can see 1/2 the spool engages the lever and the other 1/2 engages the arms.
(https://lh3.googleusercontent.com/pw/AM-JKLWbUNplR2LlbXcz7QuYqmdRA2CZOnTrK2eQcTJFj83TiLLRfdMv-T4bv-zq9CTv2F8NedwB2CPvMUamBnK34Osqc43YF5PVeFdsgmeYkgsQqeB3O98XTRNfvX75mUd_pvcjbK1bE2P6k_3rNjQi_jl_HQ=w724-h965-no?authuser=0)
I'm going to stop here with this post and continue in another one, just to keep the length of each post reasonable.
Up next will be the carrier assembly which turned out to be a bit tricky for me.
Enjoy!
Mike
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Very nice Mike - for some reason I particularly like the use of a 20p for size reference in the pictures!
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Very nice Mike - for some reason I particularly like the use of a 20p for size reference in the pictures!
Back before I retired, my business partner was Scottish. I send him photos every once in awhile and have to give him some familiar reference, hence the 20P coin! And I do like the looks of it also!
Mike
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Ok, we're down to the last part for the hnm mechanism, the carrier. It's a complex bit and it took me some time to figure out the best approach for it.
I started on the lathe and turned out what is essentially a disk that has the correct ID, OD and thickness for the finished part. Nothing too complex so far, so here's the resulting bit on the print.
(https://lh3.googleusercontent.com/pw/AM-JKLWaTuSzQhJ90vu1SMYBmY_9ltjU8pYl1D-QIh5lAN3a7uJB0PwqnAyLiPbY-z9PQ28N7RosSHgaeoblsZgYAPwBIRuwIsVc0a7Evbq-UVW8EyXn2qR2kl4oSw4wU6Uij2M4nlHmyiTRDdmnHZ67wJAbRQ=w724-h965-no?authuser=0)
I decided that the only way to do this part was to make a fixture as seen in the pix. I squared up a piece of 5/16 flat AL stock and made the sides exactly 2.00" and then bored a locating recess and tapped the center 10-32. You can also see a small locating pin that fits the fixture and the carrier so that the carrier can be exactly located on the fixture. I also make a small hold down bar, not yet shown in the pix.
(https://lh3.googleusercontent.com/pw/AM-JKLXzYJGGr3u_lgeQxsKZdWaRShdwZk1LqdTXKTEx8TonDLwWXx23PyDiGUdSlyXoJA_0r-EwDa1T_g_WF3dLkwFMeGzlTlBdntEfrw4gjSG_3wvm8KI_rss_b8eIUkDTNLVU4OjpHjpef1YuVRZW-d8Fyw=w724-h965-no?authuser=0)
And here's the first op in the mill. You can now see the hold down bar that secures the carrier to the fixture plate and allows each side to be milled down to the .063" thickness called out. I started by locating the center for the fixture in x and y so I'd end up the correct dimension in the middle.
(https://lh3.googleusercontent.com/pw/AM-JKLWxT9iy5qq1VhKZH94T_jhVN7xHLaSzrs27_00in0HVuJv4DBOvOtVBvovAhbs9tltUoq3QMQCbMf6fBslJgLmS5Tr3vNzdfyXjWG2olfeuxdPNHdUZW3dso8GFlXAMV4jpV--lG2BnwWboXXlm-uIUuw=w724-h965-no?authuser=0)
After milling the sides, I drilled 6 holes thru the carrier with clearance size for 2-56. Then I drilled and tapped the same holes in the fixture plate 2-56, which is shown in the pix.
(https://lh3.googleusercontent.com/pw/AM-JKLUDBIgVWu1dWEfrFF5GFqGN6c7EKFDbLfBkXy4IoKpFeNXNTC4OegAxoma0jqg86vtjJq8D-llAGFoDincaYnSmWYk9YQRLIMhwTJ1WlSiF-Dh8POGRMez5DxAcX4kvb4j5LAaWNd_xwJaVHMmsmZmdTg=w724-h965-no?authuser=0)
Once those holes were drilled and tapped, I could secure the carrier to the fixture and remove the hold down bar and centering plug so that I could mill the center bit away. Shown is the milling operation using a 3/32" end mill spinning about as fast as the Bridgeport can go. I took it slow and easy and used my MQL system to make sure the chips were cleared and the cutter and work was well lubricated. The nozzle for the MQL is on the left of the pix.
(https://lh3.googleusercontent.com/pw/AM-JKLVrxrTS-_IU2zNK4xZ0MYwzl2u7oakhDuYAwIe1zWyqPwVgq9pZGiJCyIdN-XRKgtxzyTkN3WrPWkPnuu_bwUuX3bBedqikxl-aZfw1K-UFQ7KdQ8KyGQQajc5kGYnLC4zpVR0SAFii9BOZUimcnCiwZA=w724-h965-no?authuser=0)
Here's where you can see why I used a square fixture for this part. Now i turned the fixture in the mill vise and drilled thru tapping size and then tapped 2-56 on one side and the other side was opened up to clearance for 2-56.
(https://lh3.googleusercontent.com/pw/AM-JKLUZsD0x5EqK0Kc7F234dBSFhoy82Nsjto8Vy3leLEb9V7xCyGPqWTQA5eT0KvbKu8jqkMcsawi-HB4dKezX4JFJrD_2jVI7eTPxjWpG3Jo5sniYOSpaizu7B8lBAoB2aX12iT3KI5GEwYCyAeGyE6lAEw=w724-h965-no?authuser=0)
And here's the finished carrier on the print. Note that i changed it up a bit from Upshur's original design. I left just a bit of material so that the 2 halves of the carrier remained together. My thinking is that this would assure easier alignment when installed on the flywheel.
(https://lh3.googleusercontent.com/pw/AM-JKLXVSpijgzuI0NEpXmBVJKK-jgYU1KwwyLzDYukkNXGEnef1R2a8p1Cp45C8z6ZPhlUYE66NtKygM2aM4VRtA2WSAfDDMzz3nUoSDdfry1XfNDrKPLoivWq3yBT03RvkYuwVr3SxPypCDgMM7EucyudDtA=w724-h965-no?authuser=0)
And here's how it will fit on the flywheel. This is just showing the general arrangement. I knew that I needed to trim down the hub of the flywheel and that became obvious when I started to fit it.
(https://lh3.googleusercontent.com/pw/AM-JKLXw1kDJhUMUZe0bkIFOhjiL9Cmy5fUJoiFnDNfF6Wf6LWUz_oVTGDcRktop7peFFTrVHO-fHfiMB6L2bZhbIuH6p56-PIRB8V-69MkbDO-3Zb_1YfE-SQxd0tEaIA4s6G3qttUQK-2GPD3JKUEdLShDtA=w724-h965-no?authuser=0)
So it was back over to the lathe with the flywheel to reduce the height of the hub on the inner side of the flywheel. I used a boring bar to do so as it could easily reach into the area and it cuts well. I also machined the spoke area completely flat so that the carrier would fit securely on the flywheel. I didn't want to mark up the OD of the flywheel but yet I wanted to not have a bunch of runout on the flywheel as I was machining the hub. What I ended up using was as single layer of aluminum foil tape which is most commonly used for duct sealing. This stuff is very sticky and is completely uniform in thickness at right at .004". And it worked! No marks on the flywheel OD after machining. It's a good product and I'll certainly use it in the future.
(https://lh3.googleusercontent.com/pw/AM-JKLUIrIbEbcC7pMs2bt3QpXYIm6rhsvkUJY-LHh8I3lqS5vDYQFex-sO_G8OjpGCUyk073DTlI9wIeySEp0tywqrFvjYcKnM-sYLphl1GYuFg0d8TI5rhvRqoPvUfJwRUntjc5sMRMtneiTnQryEtOuM7dA=w724-h965-no?authuser=0)
Then back over to the mill to drill and tap 6 locations 2-56 to hold the carrier. I just centered the flywheel under the spindle and used xy coordinates to locate the holes. Note that I continued to use the foil tape to protect the OD. It continued to work!
(https://lh3.googleusercontent.com/pw/AM-JKLV_mmPn7YLjjwoa0-m7hh_66AabZRKN8_995cazTWsM_lFCkIGGIx5nOUf1G_rkqsUkkbpsqKirJzWqRZUjBhB-Yv1AeiVvP31IaGQ6t9_o1FeiZQwTvzbOlewAMamxp2FjLKAROP0FydtNWH0RIlXV4g=w724-h965-no?authuser=0)
Here's a mod to the flywheel that I had to do after I started trying to fit the hnm mechanism. Since I used a cast flywheel, the hub and distance at the spoke hub webs was larger than Upshur's design. So where the hnm arms are located I used a 3/16" end mill to remove the material at the 2 locations so that the hnm arms would close properly.
(https://lh3.googleusercontent.com/pw/AM-JKLVNAVGwjGimWy-EAg7iOtL4SAt4HA_WQ5UYegzwto0DvKf2eL2XhzoHGiILkMmh5lAA-s4ucFlEPL-jjO3SY5yGdD-qgI4hrjFZNJe9qaMfndGSlKpmMVAjii9NG9DjBRowQNzeL2biUSgdcMuDFrJlnw=w724-h965-no?authuser=0)
Here's part of the fitting process. Everything mounted but the shoulder screws that I wanted to use were interfering just a bit on their heads. Plus you'll note that they prevent the 2-56 mounting screws from being installed at 2 locations.
(https://lh3.googleusercontent.com/pw/AM-JKLXAVXJdkrAN5a01Y2vdyAUdphiT7GdHpt5_AjcYNWLESSVRQuzwTXDpn_sw6ZXLQhY1Cb-1253ojgrWLlDe_vhX_bfMMNOf2YubLloDpPnFIQ1Xt65sEUrs7t63qbSjaEiNL1sDpxSli9raJitOUVK1dg=w724-h965-no?authuser=0)
And here are some fitting mods to the hnm arms. I rounded the ends and kept trying them until the fit the spool properly. I also shorted the other short arms so that they'd allow movement toward the hub. I had to do this since my hub OD was a bit larger than Upshur's original design. Rounding was done on a belt sander after bluing and marking with a radius gage.
(https://lh3.googleusercontent.com/pw/AM-JKLUwPW7wV9qGKeXbtuY3S97GEoVmNb_PqoctE7z1OUp15YsGs_1ssfOkrkTfTw1AIj30BBLovD5BdwyYGir_K03oVLJJui3Kh4k9ftdPhiI0gqL_buKoZGcJvWq2JuMz80AL_6npit6p4WUWXTfHD8hbfg=w724-h965-no?authuser=0)
To cure the interference issue on the 2-56 screws, I made a couple of .093" pins out of drill rod and made grooves on each end of them to accept a 3/32" e-clip. I didn't use anything fancy for grooving. All I did was to grind down a bit of HSS to .020". The grooving actually went very well as the tool was sharp and I didn't have to go very deep. In case anyone hasn't used these very small e-clips before, my advise is to buy some extra ones as they are extremely likely to launch themselves into another dimension, never to be seen again, if you slip at all during installation or removal. The best tool I found to use was a pair of the locking type of hemostats.
(https://lh3.googleusercontent.com/pw/AM-JKLWVf-tB8qDMGMxS1OUqvuE2zYTrSonUFv5GyT1q8_u6drgBq_iMQ2VkG0r-n_NY45bIqY1TBQRCGnaLDZeWrd0fJ0te2pGAN-xxIa87_w45kMFaSqKOuqv7vVcNvKTi1Zx91cETqlIdMNUJOSr5W4j_ug=w724-h965-no?authuser=0)
Next was lots of assembly, trying, dis-assembly, fiddling around and repeating the cycle ad nauseum. I'll show only a few pix of some of the more interesting tweaks that I ended up doing.
The first tweak that I did was to shim up the hnm lever in the camshaft slot. For whatever reason it was fairly sloppy and my thinking was that was perhaps not moving freely as the end of it engaged at different places in the spool. So I made a thin brass shim just by drilling and parting off a piece of .25" brass. I was shooting for .012" and I managed to get pretty close. Even the Queen nodded her approval.
(https://lh3.googleusercontent.com/pw/AM-JKLWj1MadVAbafEBYadoEvAptLUIPl8mT30-ZAPYHvZdK__8fNGcLN6X1zvJe7c1SoN2AYFLDQoBhnhz5u8IOiV0rI8njlAn-y0pz-1Awfikzp7Awtj0JmK3NzoqtTlVF3Y61Q4Lc1Jqov-FOtfp2Z8Gadg=w1285-h964-no?authuser=0)
Here's the shim in relation to the hnm lever.
(https://lh3.googleusercontent.com/pw/AM-JKLUW4jguCjbjy4BhZED9XbEsHHz1Iwbml5zSQeDktn8_TFjuu-KMMi1Amve1abzwUR36rVqjFuDX7nBwb97SGiHBcyUC5tnty3zRDYUMAOCrkOhkRyD5hRE0w3hE6y7waZ_Xr2DhLfDMlc_0MCrsucQHiw=w724-h965-no?authuser=0)
The next significan tweak was that I built in the end of the hnm lever with silver solder. I got overzealous when I was shaping it and got it way too sloppy where it fit in the spool. I just cleaned it with acetone, fluxed it and applied the silver solder to the end and then reshaped it. Here's the lever after building it up.
(https://lh3.googleusercontent.com/pw/AM-JKLVcYDF4TsFBf_8VglqwU6_eb6iqn57Iuk4hoSWMcfQb28J1MkxfSnwjAwu9rtDRh6FNzBHzdM5_9FkNstfwn2qLYhwY4LwgKFf2aSwWgmYstveeqlf06zZUO0ZoTtZU82SDD31LN5LsMYK8tPC9g-MTyg=w1285-h964-no?authuser=0)
Now that I managed to get everything moving freely and pretty well as it should be moving, I moved the hnm mechanism by hand first to its 'hit' position, that is low rpm and made sure that the lever did NOT engage with the stop. That can be seen in this pix.
(https://lh3.googleusercontent.com/pw/AM-JKLVp88-LD8w9JBbCjXTdpK0jus6zOTyXlTxXJUqVbsUFe6Imj-jQ-xHm5VSL9m2h7beZ6znnE80Ny0vgPYUrYrpS84Ve0Fw6Ompxvzyer2THivDIAM8AFCyxDp-yWZRyag8aCBPF54N7a2vQkmxxeR0vxg=w724-h965-no?authuser=0)
Then I moved the mechanism by hand to the 'miss' or 'ball-out' position and as you can see the lever clearly engages the stop which in turn locks the exhaust valve open.
(https://lh3.googleusercontent.com/pw/AM-JKLX8lsc8PBny-3um3lOZJD7dDGjpGTwKOM-mZ-QawRo5dX5WclK2WZ2RXfg2XQIdZh7W3h5nu7-qryb3ozwHNUNokhlPs-DdfRp4FIDq2Ee4ikn5ZgQryHnf57geLQ8yKKBAdnaEPsxhKnk1PZW7ka_6wQ=w724-h965-no?authuser=0)
And here's a view of the hnm mechanism fully installed showing the weights and springs in their 'hit' position. So far so good.
(https://lh3.googleusercontent.com/pw/AM-JKLX2BgxFxYPK2x5uTVaSwbXruFuB3jAdlJiqCeZjTWgXYaTrEnCWSR-nX9ADJHjOUZ9QTcqAZRedBoD7UaQopM3CYXfTs3V3R9w3gaHfWljCzoTv3WKpl2Pv4STfBO0FCRgNTmtdq_YEJUYb1eLNA1AB2w=w724-h965-no?authuser=0)
So, I was feeling good at this point and decided to run the mechanism with my drill motor as I could easily control the speed and could hopefully observe the hnm mechanism in action without the concern of actually trying to run the engine. Well, let me tell you what NOT to do. I had the ignition system all wired up but NOT secured in any way and had NOT paid attention as to where everything was laying. So after some time, running the engine with the drill motor, the ignition wiring decided to leap into the hnm mechanism and you can see the result.
(https://lh3.googleusercontent.com/pw/AM-JKLVYENL8cWrcs0CFRd9yZ9UINhXPHjgEjiYDykXqKPRcIhL4fQfOyQgBM5Z_St2-6gpfMUdKPaXHOjA9wfnb-wE8LKRD483Ur7m0z20KU1DjjmhHCcuefnAEUD5JXIDvVkkTWhwIhe_vM4CId_DIERa_Wg=w724-h965-no?authuser=0)
That's a destroyed plug wire, ground wire, and the worst thing was that the ground wire was ripped out by the roots from the S/S CDI module and there's no obvious way to solder it back as it's all heavily potted inside.
So, what's next for our now incredibly stupid feeling small engine builder???
Stay tuned for the next post to find out the answer!
Mike
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Aw man! Sorry to read about your ignition wire catastropy! That's no fun at all. I'm sure you'll get it sorted and looking forward to see how you work it out.
Very nice work on the hit-and-miss mechanism, Mike!
Kim
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Bummer about the ignition Mike, but if you have a solder iron use the point of it to dig into the potting of the ignition module you may be able to save it. At this point there is nothing to lose trying. Very nice work by the way.
Regards Don
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Sorry about the ignition mishap Mike. Other than that, everything is looking great.
-Bob
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Nice parts :ThumbsUp:
And what a bummer with the Ignition :hammerbash: - haven't done that particular error, but my own list is long enough :facepalm:
I can only agree with Don - many different kinds of potting epoxy formulas can be 'destroyed' with heat ....
So if your soldering Iron is temperature controlled - try around 150C first and increase if it doesn't touch it ....
Best wishes
Per
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Ooof! Sorry to see and hear about the ignition Mike. Alas - I do that kind of thing too often. I know you'll get that all fixed up, but vexing for sure.
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All, thanks for the sympathy!
After I managed to tear up my ignition wiring and pull the ground wire out of the CDI module by the roots, I started working on recovery from the mess.
First I had to rewind the hnm springs as they were both destroyed. This was actually fairly easy as I have the winding mandrel made and have a fairly decent winding guide for my lathe and I had plenty of .014" music wire left. So I got the springs made and reinstalled on the engine.
Next I email Roy Scholl, the builder of the ignition system. I sent him a few pix of the module and explained what happened. Within a half a day, he emailed me back and suggested that I solder a new ground wire to the negative side of the LED. That side of the LED is tied directly to the ground plane of the circuit board and is fairly easily accessible. So that's what I did. My backup plan was to dig out a bit of the potting material around the ground wire location using the tip of a hot soldering iron.
Luckily Roy's advise was spot on! So after rigging everything back up on the bench and testing with the spark plug removed from the engine but clipped in with a clip lead, I was extremely happy to see that I still had a good CDI module that still produced an excellent spark! So I was now back to square one in terms of trying to get the engine working in hit-n-miss mode.
I didn't take any pix of the process of working on the mechanism, but I did play around with spring tension quite a lot, all the way from changing to a much higher spring rate springs to going down to only one light spring. What I found, like many others, is that heavy springs increase the engine RPM and lights spring lower it. I also installed the small leaf spring as per Upshur's original plans. That helped a bit, I think mostly because that spring makes the lever follow the spool's motion a bit better. But I think it would be better to have an adjustable spring in place of the leaf spring, as that would allow a bit of counter-action to the governors springs which would provide an easy way to adjust speed and to probably optimize the hnm mechanism and action.
So, without further ado, here's what happened:
Here's the first run of the engine look at the hnm side so you can see the weights and springs in action:
https://www.youtube.com/watch?v=XUwN_to9GkM
And here's a view of the engine from the other side with the hnm mechanism engaged and working:
https://www.youtube.com/watch?v=0J0nUNpUci0
And lastly, here's a final video after I got the hnm mechanism working about as well as I could. I'm sure it could be a bit better, but I think I'd have to redo the hnm lever to add and adjustable spring to it.
https://www.youtube.com/watch?v=z15DHkBOmu4
So that it! I'm declaring an end to this build! I will install this engine on a nice wooden base and install a brass name plate on the base and I'll get that done in the next few days. When that's finished I'll post the finished engine in the showcase portion of the forum.
Enjoy!
MIke
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Wow - nice recovery!! Love the sound of it, very well done! :ThumbsUp: :ThumbsUp:
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Nice job Mike. Reminds me a lot of what I went thru when I built the Kerzel hit and miss engine. I have three or four different hit and miss engines, but they are all running viton rings. I think the Viton ring cause considerably more drag than cast iron rings, so my miss cycles were never as long as I wanted them to be.----Brian
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Congratulations Mike, job well done! :ThumbsUp: :cheers:
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Congratulations, Mike! Your engine runs great!
Love the sound of that hit-n-miss.
Glad you found a good solution to your quandary.
Kim
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Nice job Mike. Reminds me a lot of what I went thru when I built the Kerzel hit and miss engine. I have three or four different hit and miss engines, but they are all running viton rings. I think the Viton ring cause considerably more drag than cast iron rings, so my miss cycles were never as long as I wanted them to be.----Brian
Brian, I'd certainly like to get a little longer coast period between hits. I did check how much drag I have and it seems very low to me. I checked it by removing the spark plug and then spinning the engine by hand and it coasts for quite a long time. But you could be correct that rings would drag even less. When I made the piston, I cut the o-ring groove to apply only about .005" squeeze on the bore ID vs the high squeeze typically recommended by the manufacturer's bulletins. But I don't have enough builds under my belt to make any good guesses on how to improve it.
The other thing I wonder about is the hit-n-miss mechanism design. Most Uphsurs that I've seen videos on seem to run about like mine, with the exception of Rudyduby's engines. On other hand, most Farm Boy engines seems to run well and coast a really long time between hits. Perhaps there are subtle differences in the mechanism??? But that's just a guess.
Anyway, I did manage to build the engine and does hit and miss so I'm happy about that! I'll certainly try to build yet another engine and see if i can manage to do better.
Thanks for taking a look and commenting!
Mike
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One of the keys to a long coast period is a powerful hit. It may help to adjust the carb and timing with a load on the engine to get the best results and then see how it runs off load.
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All, thanks very much for watching this build of my version of Upshur's Horizontal Farm Engine. I really appreciate the feedback and comments!
I'm officially wrapping this build up and am already on to the next one.
I'm in the process of posting some final pix of the engine in the Showcase area of the forum at this URL:
https://www.modelenginemaker.com/index.php/topic,10675.msg245558.html#msg245558 (https://www.modelenginemaker.com/index.php/topic,10675.msg245558.html#msg245558)
I put it on a nice wooden base with a name plate. I'll add just a few comments to the showcase thread and that will be that!
Thanks again!
Mike