Why did my Flywheel Wobble?

Edited By mgj on 19/05/2011 06:05:19

Yes, I would have thought that boring the hub would be the first step in machining a flywheel. Are there disadvantages in doing this first ?

NOTE : I did a search for '' maching a flywheel'' but turned up no results.

Is the Flywheel keyed to the crankshaft? This can often cant the thing over. I think I would bore the hub when machining the second face with the first now machined face against the faceplate as routine.

regards Martin

Hello Steve,

The one thing you haven't told us is how you corrected the situation having wetted all our appetites!

Please tell us, it might also help others.

Regards Brian

This is how I machined my flywheels; the front face of the rim and boss, the outer diameter, and crowning, and the bore all machined at one setting:

Then turned over and the rim and boss faced to final thickness.

Andrew

I have often thought most flywheels have six spokes,and a awful lot of other castings/forgings were six sided yet most faceplates have two master slots set at 90 degrees making it easier for four spoke or square workpieces,though after a century or so Colchester did make six slot face plates by which time nobody was making flywheels. all the above are good comments though I will add some more, beware of workpieces that are stiffer than the faceplate overclamping will distort the faceplate. Holding work on stub mandrels can cause chatter problems as the bore on most flywheels is small relative to diameter. My method is mount three alloy blocks on the faceplate spaced two thirds up each spoke, then use three clamps on the spokes directly over the blocks,on heavier flywheels a further three blocks are mounted equispaced onto the face plate near the rim , three bolts screwed into the blocks are screwed outwards ,like chuck jaws , to just touch the inside of the rim.This helps to keep the flywheel in position and takes any radial strain off the spoke clamps . rough machine bore .o/dia and face ,sometime if the flywheel is spaced away from the faceplate the other face can also be machined .then relax the spoke clamps ,this allows any stress in the casting to be relieved but it remains in position ,held by the three bolts. Then leave as long as possible,tighten the clamps Finish by machining the rims and the bore last, on small wheels the hole should be bored a fewthou undersize and finish by reaming.

Use HSS tools for finish boring ,I have machined a quantity of flywheels from 6ins to 2 ft for steam and ic engines plus refaced rusty stationary engine f/wheels .