Turning the stub shaft saw crank for 9 tooth inboard - Printable Version +- Vintage Karting Forum (https://www.vintagekartforum.com) +-- Forum: Resource Archive (https://www.vintagekartforum.com/forumdisplay.php?fid=88) +--- Forum: Restoration Advise Section Basics to Complex (https://www.vintagekartforum.com/forumdisplay.php?fid=90) +---- Forum: Engine Advise (https://www.vintagekartforum.com/forumdisplay.php?fid=58) +----- Forum: Mcculloch Engines (https://www.vintagekartforum.com/forumdisplay.php?fid=59) +----- Thread: Turning the stub shaft saw crank for 9 tooth inboard (/showthread.php?tid=1136)

Turning the stub shaft saw crank for 9 tooth inboard - steve welte - 03-01-2017 This is how I make the stub shaft 250 saw crank for inboard 9 tooth use. I take the 5/8" shaft and grind it down to 9/16" using the tool I made here. I made a tool holder for my dremel tool to be used on the lathe. I first use the 60 grit roll cartridge for roughing the shaft. It takes about 3 cartridges to get the shaft to within about .010 of the finish size of .960. At that point I switch over to the stacked cut off wheels because they are harder and grind more consistent. Then I finish the shaft with some 320 wet paper. Max torque makes a clutch for this setup for the mac 49 class. The cranks you can get for $20.00 or so in the chainsaw part of E bay. In the midwest we have about 20 of these running and have raced them for the last 5 years. Only 2 failures have been seen. One the threads broke off because the clutch wasn't seated against the crank stub. The other a guy broke the end off because he forgot it was left hand thread. We've won a ton of races using this cheap crank. It takes about 1/2 hour to grind it down. good luck.  a good machinist has a better way to do this but i have few resources available and it has worked perfect.