I wrote thread #20 yesterday but I forgot to post it so two for today
Thanks Danuzzo
Cutting out the cam shaft supports.
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Hot off the mill.
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The cam shaft drive gears can be either helical or bevel gears. The helical gears are more compact but much more expensive and a 2to1 ratio is also rare. I will be using the bevel gears but there are still problems with size. In order to get the pinion gear big enough so I could mount it on the crankshaft I had to go to Mod 1.5 which has good sized teeth on it and that makes the driven gear quite large.
Here is a shot of how I modified the pinion gear to fit a 12mm shaft and shorten it up as much as possible. There isn't much meat left on the inside hole. I was able to shorten the length of the gear considerably but that meant most of the original set screw holes were cut away. I pressed a brass collar over the gear and drilled and tapped through that for the set screw.
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The driven gear was reduced in diameter by 1/2" which meant cutting away the outside 1/4"of the teeth. I didn't need the full length teeth for this application anyway.
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I mounted the cam supports on the engine and there was just enough room.
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The driven gear is only about 0.050 away from the engine base and I now have 0.950 of shaft left for the flywheel.
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Quite happy with how things turned out. (maybe I should make my crankshafts longer in the future)
I was turning the engine over with the drill when I realized I had another big problem. Even at 250 rpms the engine wants to leave the shop. I will work on that issue next.
Thanks for looking
Ray