Best method for flywheel construction? HELP

[smuttley]

Hi All,

What is in your opinion, the best and most accurate way of making a flywheel and shaft with two bearings on either side of the wheel, last one I made wobbled (a lot). Do you make the shaft first and slid the wheel on too it or turn the flywheel with shaft attached and turn the hole thing in one hit?

My Stirling engine don't like the wobbles, and won't start,

Regards

Steve

[Alan Haisley]

Steve,

I have only made a few small flywheels. That being said, I'll describe a method. First, prepare a somewhat round blank. Chuck it in the lathe. Face the piece flat. Reverse it in the chuck and face the other side flat.

Now, although you may not have a truly round piece, it will have faces reasonably flat and parallel. With a spotting drill or center drill held in a tailstock chuck, start a hole. If the shaft diameter is such as to not overpower your lathe, you can drill out close to it and then use a reamer held in the tailstock to finish the hole. On the other hand, if the shaft is too big, drill out large enough to use a boring bar and bore out the hole to size.

Now you have some choices. If you have, or can make, an arbor that fits the wheel hole, you can mount the wheel on the arbor and turn the rim true. You could instead trepan between the rim and hub deep enough to use the chuck with jaws reversed to grip the inside of the rim. That will let you both turn the rim as well as trepan the other side. This way you can produce a flywheel where the hub width is greater than the rim width if desired. Of course, if the rim width is not such as to allow you to grip it from the inside with the chuck, you will need to produce an arbor to hold it with.

When doing this work I use a 4 jaw chuck so that I can use an indicator to recenter on the bore when I need to reposition for additional cuts.

Alan