I want to turn the back side of my flywheel (1 inch deep, 6 inch across) mounting it on a stub mandrel.

It has a 22mm bore.

I have no steel around that size, but I do have a piece of 25mm aluminium bar which could be pressed to service.

Is that a good idea? Or is it to soft?

Just to add a note, I then need to turn it round and finish off the first side so it needs to go on twice.

Thanks

Iain

It's not pure aluminium – I had some of that a while back and it was HORRID to work.

It turns very very nicely. Much better finish that steel or cast with more or less any tool.

I hadn't thought of holding it by the inside of the rim. I'm not convinced that the chucks I've got extend that far.

However, it's worth giving it a go. Chatter is a problem with my machine pretty much all the time, so no need to make it worse!

Iain

I did as suggested and just about the other side sorted out. The wheel was about 0.1 mm off centre held in the 3 jaw on the inside.

After taking off the bulk of the metal this way, I reverted to the aluminium stub mandrel to finish back to more accuracy and it worked a treat.

More details on my build log…

Iain