Using a dividing head to machine a flywheel

[Mike EdenParticipant @mikeeden84652]

My lathe has limited capacity and I need to machine an 8” flywheel. Is there any reason why this cannot be done using a rotary table on a milling machine?

[JasonBModerator @jasonb]

Although I have not done metal ones that way, only wood I have machined features into the rims of some similar sized cast iron ones on a 6″ rotary table.

You need to watch out for backlash in the gears so adjust as much of that out as you can and lightly nip up the table locks to give some drag and then proceed with light cuts other wise you will get a juddering cut. The milled finish is unlikely to be as good as a turned one so after doing the best you can by milling make an arbour so the flywheel can be spun slowly by the mill while you used some emery on the rim and sides.

Drill and ream the bore first then move sideways to do the edge without removing the flywheel from the R/T to ensure you keep things true and concentric.

[SillyOldDufferModerator @sillyoldduffer]

What Jason said.  I’ve done it once, and found a small diameter cutter at high rpm juddered less.   The result wasn’t nearly as good as a lathe, but maybe my technique was poor.

Dave

[JasonBModerator @jasonb]

Not easily seen but there is a piece of metal clamped to the angle plate which gave a bit more support to the overhanging rim while the half round balancing grooves were cut with a 7/16″ ball nose cutter.

Not too shabby

[Paul LousickParticipant @paullousick59116]

Take light cuts and watch for backlash.

I broke the teeth on a 6″ rotary table (good quality, made in Japan) when milling a “J” shape profile for welding on the edge of the tube plates for my boiler. Steel plate 16mm x 250mm dia. The RT, like many others only have a worm gear drive with small teeth that can easily be damaged.

[Mike EdenParticipant @mikeeden84652]

Many thanks for your comments! There were a few things I hadn’t thought of such as the potential to damage the worm wheel gear.

[Martin KyteParticipant @martinkyte99762]

I don’t know what size mill you have but if you can run the spindle slow enough you could mount the flywheel on the spindle and with a lathe tool fixed to the table machine it like that.

 

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