CB,
Here is a little flywheel fix method that I always use for low shaft torque engines. I have found it ideal for finger engines etc. It can only be used with ball raced bearings.
If using twin races, they would either have to be stacked side by side, or a small spacer between the two inner races to stop sideways pressure between the inner and outer races.
Basically, you trap the bearing inner race between the crank disc and flywheel hub. Making one complete unit with a spinning race in the middle.The thin spacers are to hold the crank and flywheel away from the outer race. They can be, within reason, almost any width, but I tend to machine a 10 thou thick boss onto the back of the flywheel boss and crank disc. The distance between the crankshaft end, and the end of the flywheel hub, can be as little as a few thou.
Doing it this way, allows narrow hubs with no room for a screw to be fitted, and it does make them look very neat, if you can file up or shape a little spinner in the lathe. But you could just as easily use a small bolt or screw with a washer.
As I said, good for low torque engines as you are contemplating. On higher torque, the flywheels will spin off. Unless of course you loctite them up to make it a permanent fix.
I hope this has explained it well enough.
John
BTW, crap-o-cad has now been upgraded, it is now multicoloured. This upgrade can be purchased from me for the princely sum of 10 pounds ($20), P&P extra. Just send your cash payment in a plain brown envelope and I will get back to you when I have found my book of last years' Christmas stamps.
