Author Topic: Webster I/C Engine - Mike's 5th Engine  (Read 2744 times)

Offline Kim

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #30 on: April 13, 2021, 05:24:06 AM »
Cool, Thanks!  I learn something every day on this forum!
Kim

Offline mikehinz

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #31 on: April 13, 2021, 03:05:56 PM »


...............Just a quick question - what's the difference between Brazing and Silver-soldering?  Are they the same?............

Thanks!
Kim

Ah, a question that I know the answer to!  The difference is essentially the temperature the process occurs at.  Soldering is defined to be below 450C  and brazing above that temp.  Both process involve flowing filler metal into a joint and in either process the temp involved is below the melting point of the base metal.  In general, in my experience brazing will not warp the parts involved but welding almost certainly will.  Whenever you melt the base material and then had molten filler, when the joint cools, the filler shrinks and tends to pull parts out of alignment.  This can be controlled to an extent, but doing so can get tricky and usually you end up straightening parts after welding, if the warping matters. 

Mike
MIke
Wichita, KS, USA

Offline crueby

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #32 on: April 13, 2021, 03:28:51 PM »


...............Just a quick question - what's the difference between Brazing and Silver-soldering?  Are they the same?............

Thanks!
Kim

Ah, a question that I know the answer to!  The difference is essentially the temperature the process occurs at.  Soldering is defined to be below 450C  and brazing above that temp.  Both process involve flowing filler metal into a joint and in either process the temp involved is below the melting point of the base metal.  In general, in my experience brazing will not warp the parts involved but welding almost certainly will.  Whenever you melt the base material and then had molten filler, when the joint cools, the filler shrinks and tends to pull parts out of alignment.  This can be controlled to an extent, but doing so can get tricky and usually you end up straightening parts after welding, if the warping matters. 

Mike
The terms for silver soldering and hard soldering and silver brazing and brazing get confused, a lot of it depends when you were taught and what country you are in at the moment! Often a topic that generates arguments. Even looking up the technical terms at manufacturers the terms vary for the same thing by country. What most of us here call silver soldering is done in the 1100F to 1450F range, or 688  to 788C. The temperature the 'silver solder' melts at varies with the percentage of silver and other metals. In the model building world, 'soft' soldering is normally the type you can do with a soldering iron at much lower temperatures. 

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #33 on: April 13, 2021, 05:43:26 PM »

In general, in my experience brazing will not warp the parts involved but welding almost certainly will.  Whenever you melt the base material and then had molten filler, when the joint cools, the filler shrinks and tends to pull parts out of alignment.  This can be controlled to an extent, but doing so can get tricky and usually you end up straightening parts after welding, if the warping matters. 

Mike

Well put. That's something I'm very familiar with - I design a lot of very large stainless steel (and other) weldments, with precision features. A lot of thought has to go into how much things will shrink, which way they will move and what we do about it afterwards. We have some impressive machinery and machinists that I get to work with, which is really excellent. They don't laugh too hard at my fumbling home hobbyist work.

By contrast, brazing I often feel is a very precise joining technology - especially when having assemblies vacuum or furnace brazed, where you cut braze shimstock for the joint you are making. It's a really wonderful technology that goes back a way. I have some experience in that, but I'm definitely not an expert. It's all fascinating stuff.
Stuart

Offline mikehinz

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #34 on: April 21, 2021, 04:30:35 PM »
Over the past few days, I worked on and finished the flywheel and the cam drive gear.  So here goes the process!!

If you go back to my first posts in this thread, I started the flywheel way back when, using a discarded barbell weight that I found in the trash.  It turned very easily and cleaned up well, but the center hole was way too big.  I didn't show any pix of the process but I bored the center hole to 1.45" and made a plug to fill it out of some sort of scrap round bar I had on hand.  I made it to be a slight interference fit in the bore of the cast iron and applied Loctite 603 to it and pressed it into place with my brother's large hydraulic press.  I deliberately made each side that protruded a specific size, 1.00" on one side to grip with a collet and larger on the other side to bear against the press arbor.  Here's a couple of pix after the center portion was pressed into place:

Side 1



Side 2 with the 1.00" stub:



Then, since I wasn't sure how the turning would go, I gripped the flywheel by the OD with my 4J chuck and turned down the large diameter stub to .75" and cut it a bit of length off of it. 



Then I turned the flywheel around in the lathe and gripped the 1.00" stub with a collet and turned the rest of the stub off.  I also slightly skimmed the side and center of the flywheel just to make sure it was reasonably true at this point.



While still held by the collet, I drilled and reamed the center hole in the flywheel to .3125". 



Next I inserted a piece of 5/16" drill rod thru the flywheel and fixed in place with Loctite 603 and let it cure overnight.  I let the drill rod protrude a bit as I thought I might require a center, depending on how the piece ran in the lathe.



The flywheel ran pretty well true when gripped by the drill rod so I lightly skimmed the rim on the left side using a left handed tool and also skimmed the face of the flywheel.



Next I used a parting tool to cut the remaining stub off to the required length, which of course also parted the temporary shaft.  It turned out that I didn't need to use a center as the flywheel ran quite true just being held with the collet.  I also skimmed the OD and sides very lightly just to make sure the flywheel ran true when mounted on the shaft. 



I heated the center and shaft up using my oxy/acetylene torch and put some heavy welding gloves on and twisted the flywheel off.  The Loctite 603 held extremely well!  You can see the residue and a bit of discoloration from the heating process.



And after a bit of work with emery cloth, I tried it on the engine frame and crankshaft.  It fit!  Note that this flywheel doesn't really resemble the flywheel as called out in the print.  It's a bit larger OD plus I left the stubs a bit larger and I didn't cut the recess as deep or as close to the shaft as the print calls for.  Most of what I did was because I'm going to mount the cam gear differently and I wanted more meat at the joint between the cast iron portion and the center insert.  In any case, here's what it looks like while in the engine frame.



Next is the cam drive gear.  I purchased this from McMaster.  It's a 32 DP gear with 24 teeth as per the plans, but it's a 20 degree pressure angle.  I got it since 20 PA gears seem more common and are cheaper and it shouldn't matter since the pitch diameters are identical to what's called out on the print.  .  This gear and it's 48 tool mating gear are of 303 stainless. 

Here's the gear as received from McMaster.  Note it's hubbed with a setscrew.



I chucked up the gear in a collet and drilled and reamed the center hole to 5/16"



I measured the available space for the gear and figured that I needed to take about .028" from the hub face to fit the available space between the flywheel and the engine frame.  Note that there's still plenty of material left for the setscrew.  My alternative plan, if I ended up needed to take off a lot more material from the hub, was to retap a hole for a 4-40 setscrew, closer to the face of the gear.  Luckily that wasn't necessary. 



Shown is the flywheel and gear assembled in the frame and luckily everything fits! 



And the last pix of this series, the flywheel, crankshaft and cam drive gear all assembled outside of the frame, showing the relationships between the parts.  Note that I deviated from the plans in a significant way here by reversing the gear orientation and eliminating the crankshaft spacer.  I felt that this is a better arrangement as I can change the cam timing even after the flywheel is pinned.  I think the only trick will be to get the timing close and to then make sure that I can get to the set screw easily when the gears go together.  I think this is possible, but we'll see when it comes time for final assembly.

I'm glad this part is completed.  Onward to the next bits!

Enjoy!

MIke









MIke
Wichita, KS, USA

Offline Ye-Ole Steam Dude

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #35 on: April 21, 2021, 05:54:57 PM »
Nice work Mike and it is looking great. I like how you centered and reamed the gear  :ThumbsUp:.

Be safe and have a great day,
Thomas

Offline Kim

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #36 on: April 21, 2021, 06:41:10 PM »
Using an old dumbbell weight for your flywheel was a pretty interesting choice.  Seems to have worked out well, and very cost-efficient!

Kim

Offline mikehinz

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #37 on: April 22, 2021, 10:21:13 PM »
Over the last couple of days, I had a bit of time in the shop and managed to build the rocker arm.  I spent a considerable amount of timing thinking about the work process as holding this part gets tricky as the machining progresses.  Here's the pix and process that I followed. 

First I squared up a piece of very rough steel scrap of unknown origin that I had laying around.  No pix of that process as it's boring and very standard.  This pix shows the very small oil hole drilled in the 'top' of the arm.  I put a dime near the hole as you almost can't see the hole without something to compare it with.



Next was drilling and tapping the 4-40 hole for the 'tappet'.  Careful reading of the drawing is required as this doesn't go exactly in the center of the stock.



I decided the best way to do the milling on this part was to clamp in on my small tooling plate and then move the clamps around as needed for milling the various bits.  I used some low profile cap screws in the plate to prove a stop and made sure I was milling so that the cutter tended to push the part into the stops.  This pix is of the first milling cut on the end with the 4-40 hole.



Then flipping the part over and putting a .125" block under the cutout area and clamping it down again.  Using that block allowed pressure to be applied across the part.  Also you can see a thin parallel being used as a work stop on the other end, being oriented with more low profile cap screws installed in the plate.



Then moving to the other end of the arm and starting to mill the features.  Note that I added a clamp screwed flat to the plate and pushed into the part.  I started to see a bit of movement and putting that additional stop in place cured the problem.  I think i got lucky as even a bit of movement is a scary thing!



Then the arm finished and laid on the print.



I made the 2 washers called for, just out of brass as I had some 1/4" brass stock on hand. Shown is parting off the .015" washer.  I cleaned this one and the other one up by rubbing them against a piece of 400 grit sandpaper laid on top of a very cheap small surface plate.



Both of the finished washers on the print.



And lastly the arm, washers, tappet, all installed on the frame.  I used an 1/8" shoulder bolt as called for on the prints.  Everything seems to be in the correct place!



This arm was indeed tricky and I constantly went back and forth to the print to make sure I was milling in the correct location on the arm.  For whatever reason, I struggled with visualizing how this all had to be done, but in the end, I made it!

All for today.  I'm currently contemplating how to make the cam and gear assembly next.

Enjoy!

Mike



MIke
Wichita, KS, USA

Offline 90LX_Notch

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #38 on: April 23, 2021, 12:57:54 AM »
Nice job on the rocker arm Mike.

-Bob
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My Engine Videos on YouTube-
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Offline RayW

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #39 on: April 23, 2021, 02:32:19 PM »
Coming along nicely Mike. Following along with interest.
Ray

Offline mikehinz

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #40 on: May 02, 2021, 04:30:24 PM »
I've made some more progress over the past few days so in this post I'll go over the cam and cam gear build.

Since I purchased a gear from McMaster and it's made of stainless steel, I needed to mod it a bit.  First to hold it, I used a 5c pot collet and shown is boring it out to the OD of the cam gear.  You can see in the pix that there's a 1/4" AL pin inserted in the center of the collet that is closed down on before boring.



I'm not showing all the steps but I drilled and reamed the gear to 5/16" and then pressed and Loctite'd in a 1/4" ID bronze bushing.  I wanted to take this additional step since I didn't purchase a brass gear and this will be running on a drill rod shaft.



Then I made the cam shaft.  This is just a a saw cut piece of 1/4" drill rod that I trimmed to length in the lathe and then used a collet block to drill the hole for the retaining pin as per the drawing.



Next I used Loctite 603 and pressed the cam shaft into the engine side frame.



After waiting some time for the Loctite used on the cam gear bushing to cure, I put the gear back in the pot collet and trimmed the length of the hub to .185" per the print, but I increased the OD of the hub to 7/16" vs the 3/8" called out on the print.  I wanted a bit more meat for the hub and for the cam itself there's enough material to increase the hole from 3/8" to 7/16" which you'll see in a bit.



Then I turned the cam gear blank, with the ID increased to 7/16" and the OD to the diameter of the lift portion of the cam, .712"  This was just from a small piece of .750" drill rod.  I spent a considerable amount of time thinking and reading about how to make a cam.  I THINK I understand the various methods being used, but for this cam, I chose one of the more simple methods and generated a drawing that has all the necessary dimensions to machine it.  This exactly matches Webster's cam drawing. 



The way I approached machining the cam was to use a rotary table with a small 3J chuck installed on it.  I zeroed the rotary table under the mill spindle and set the DRO to 0,0 and the RT to zero degrees rotation.  Then I rotated the RT CW by 31.22 degrees and moved the table in X by more than .281" plus 1/2 the diameter of the end mill, so that the cutter just barely touched the blank.  Then I started taking cuts using the Y axis on the mill until I cut one side of the cam flank to the tangent dimension of .281.  Shown is just after the first flank of the cam was cut.



Then I brought the mill table back to 0,0, rotated the RT CCW by 31.22 degrees and moved the mill table in X .281" plus 1/2 the EM diameter the opposite direction and started taking cuts using Y on the mill until the flank tangent dimension was .281".  Shown in the pix is just after the 2nd flank of the cam was cut.  The cam lobe is now clearly apparent. 



Then brought the mill table back to 0,0 and the RT back to 0 degrees rotation.  This time I moved Y just beyond the .281" diameter and moved back until I just started cutting.  Then I used the rotary table to move 121.22" degrees both CW and CCW from zero so that the non-lift portion of the cam was brought to the spec'd diameter.  And yes I did convert the decimal degree notation to degrees, minutes, seconds for use on the rotary table!    Shown the non-lift area of the cam being cut.  End mill was 1/4" 4 flute carbide cutter. 



A pix of the cam after cutting but before being parted off.  I did work the cam over on a Scotch Brite wheel to remove any cutter marks and to blend the transitions to the lift portion just a tiny bit.  You can also easily see the increased ID of the cam thru hole. 



Checking to make sure the cam ID fits over the cam gear hub OD.



Then back to the lathe using a 3/4" collet to part off the cam to the required thickness of .185" 



The finished cam laid on its side on the print.



And the finished cam stood up on the print after further deburring and a bit more polishing.  To me, the cam looks good with a good enough finish for it's intended use.  A gray Scotch Brite wheel gives a pretty good finish, but you have to be a bit careful with it as you can round of edges fast!



Then prepping to Loctite the cam onto the cam gear.  I cleaned the parts with acetone and then blew them off with an air hose prior to applying the Loctite.



The cam gear and cam assembled.



And the last pix, the assembled cam and gear on the engine frame.  I still have to check the fit between the crankshaft mounted cam drive gear and the cam gear, so I hope it fits!  But hope springs eternal in ole retired men!



All for now.

Enjoy!

Mike


MIke
Wichita, KS, USA

Offline RReid

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #41 on: May 02, 2021, 08:20:34 PM »
The Webster is on my short list of future projects, so I'm following along with real interest. The cam looks great, nice work!  :ThumbsUp:
Ronald

Offline Art K

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #42 on: May 02, 2021, 11:01:08 PM »
Mike,
I have a lull... in my homebrew process. Life has been very busy of late and this has been my first chance in about a month to do something not related to my parents estate. So while I have time between brewing steps I've been reading about your Webster build. I like your work and how you are personalizing the design to make it your own! I'll try to keep up with your build.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Bearcar1

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #43 on: May 03, 2021, 02:39:52 AM »
Nice work Mike. I have been following along since the beginning.  :ThumbsUp:


BC1
Jim

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Re: Webster I/C Engine - Mike's 5th Engine
« Reply #44 on: May 03, 2021, 06:30:28 PM »
Very nice - some really excellent work there. I particularly enjoy seeing that combination of milling and using a rotary table or dividing head to make complex parts.
Stuart