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Thread: Back to Steam--

  1. #151
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
    Posts
    7,652

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    Other than a bit of cleanup work, the crankshaft is finished. It fits where it is supposed to, goes round and round without smacking into anything, and is reasonably straight. I have found that these crankshafts for double or triple cylinder engines share a lot of characteristics with a wet noodle. When everything was first pressed together, without the main crank sections being cut out, I set one end up in the three jaw chuck on my lathe, right up to the first web plate, and put a dial indicator on the extreme outboard end. It had 0.135" total runout. After the main crankshaft was cut out from between the web plates, I stuck it back in the lathe and it measured 0.060" total runout. Then it was simply a matter of light smacks on the outboard end with a soft faced hammer, and chasing the high spot around until I got it down to about 0.008" total indicated runout. I went across town today to my tool shop, and bought a 1/16" straight flute reamer and the appropriate drill to go with it. I may drill and pin the web plates to both the main crankshaft and the con-rod journals. I have to think about that one overnight. After I was finished in the lathe, I installed the crankshaft in the engine with the bearing hold down bolts loose, gave it a few spins just to be absolutely certain that it didn't hit anything when turned thru 360 degrees, then tightened down all the bearing bolts. The Loctite I used takes about 20 hours to completely "set up". I would prefer that it "sets up" with the crankshaft in the position it will occupy, rather than just setting out on the bench. I ended up using 5/16" drill rod for the crankshaft, not because it is "better" than cold rolled steel, but because cold rolled steel shafting comes in about .0005" undersize, and I wanted more interference fit than plain cold rolled would give me. Drill rod comes in "full size", and that extra .0005" on the diameter gave me a much better press fit. I used my 2 ton manual arbor press, and had to put a 3 foot long pipe on the handle to give it enough "grunt" to press everything together.
    Brian Rupnow

  2. #152
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
    Posts
    7,652

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    I got up this morning and drilled/dowelled the crankshaft webs to the main crank and to the rod journals. I don't think that in a million years this engine would create enough torque to make this absolutely necessary, but it only took an hour of my time and it gives me the feeling of a bit more security. I guess the next thing up will be the connecting rods.
    Brian Rupnow

  3. #153
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
    Posts
    7,652

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    I decided to do something easy this afternoon. My flywheel is going to be a two part assembly with an aluminum center and a cast iron outer rim. I save all my short ends of stock, and keep using them until there is nothing left to hang onto with my chuck. That lump of cast iron just to the right of the crankshaft is going to become the flywheel outer rim.
    Brian Rupnow

  4. #154
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
    Posts
    7,652

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    I would just love to be doing some more with this project right now, but the pain in my back and right leg is just so ferocious I can't. All I can really do is lay around on my heating pad and take the Oxycodone pain pills my doctor has prescribed. I have a raging case of Sciatica that is still raging after two weeks. I have also developed something called "drop-foot" in my right foot, which is associated with the sciatica, and I'm walking a bit like "Lurch" of the Addams family. Getting old is not for sissies!!!
    Brian Rupnow

  5. #155
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
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    7,652

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    I seem to have worked my way through the greatest part of the pain, with the help of physiotherapy, Oxycodone, and time. I am still feeling a bit fragile around the base of my spine, but at least I've quit hurting. I really don't know what caused this flare up of Sciatica, but it was either using a different computer chair, or standing too long at my lathe. Whatever it was, thank God it's gone. I am not going to be machining anything until at least mid October, because I want to make sure this is totally cleared up before I do anything that might cause it to come back. In the meantime I will take all of the solid models I downloaded them from Grabcad and convert them to 2D dimensioned drawings so I will have something to work from when I do start machining again.---Brian
    Brian Rupnow

  6. #156
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
    Posts
    7,652

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    I couldn't stand being idle any longer, so--This morning I turned the final outside diameter on that short end of cast iron that was in my lathe, faced the outer face, and bored it for a "push fit" of the aluminum center into it. Coated the outside of the aluminum center with 638 Loctite, and pushed it into place. (a "push fit" is half way between "get the hammer fit" and "Oh damn, it falls through fit").
    Brian Rupnow

  7. #157
    Join Date
    Mar 2013
    Location
    West coast of Canada
    Posts
    481

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    Glad to see you on the move again. And the sense of humor is alive an well.
    I have bouts like that. My frame is on the light side and after many years working on heavy equipment it has taken it's toll.
    I do try to keep busy if only working out what I should do next and siting in front of this screen too long doesn't help either.
    So I had better get my backside in gear and head out in the yard to tick off a couple of chores.
    Larry

  8. #158

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    Quote Originally Posted by brian Rupnow View Post
    (a "push fit" is half way between "get the hammer fit" and "Oh damn, it falls through fit").
    One of the guys I worked with called the latter "a knurling fit" -- "It will fit perfectly after you knurl it."

  9. #159
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
    Posts
    7,652

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    My, but there is a world of set-up work in these con rods. By the time I'm done with two of these things, I'll be qualified to start machining ear-rings for my wife!!
    Brian Rupnow

  10. #160
    Join Date
    Mar 2008
    Location
    Barrie, Ontario, Canada
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    7,652

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    I'm now into "second set-up" with the con-rods, machining the other side. Same fixture, but with a spacer washer of appropriate thickness between the finished big end boss and the fixture. The fixture is very handy for this kind of work. I know it doesn't look terribly different from the previous picture. After this operation is performed on both rods, then I have only to round the small ends and do a little "clean up" with my jewellers files.
    Brian Rupnow

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