Automotive starter ring (ring gear)

Hello

I wonder if anyone could advise on this?

I have an Austin Seven flywheel from which I want to remove the ring gear. This is the early type where the teeth were milled(?) onto the solid. I.e. not the type where you heat a gear ring and shrink it onto the flywheel.

Most people would probably do this on the lathe and I have sufficient swing to do that. However I am worried such a heavy interrupted cut will bash the hell out of the lathe headstock.

I'm thinking a gentler approach would be to mount the flywheel on a rotary table and cut down just behind the teeth with an end mill or slot drill.

Is this a sound tactic?

Thanks in advance for any help. Martyn

PS Not an angle grinder please! They terrify me.

Suggest that you get your ring gear first, so that you know what diameter to turn the the flywheel down to.

To minimise hammering the lathe too hard, take things gently with a fine feed and shallow depth of cut.

Lots of minor smacks as against a few sledgehammer blows, would be my approach.

If the lathe can swing an Austin 7 flywheel it will be fairly large, heavy and rigid.

Good luck!

Howard

Could you chain drill the centre out and finish the bore on the lathe? Alot quicker than milling.

As Howard says. A lathe that can swing that diameter should be able to manage intermittent cutting.

Steve

Alternatively, use the lathe but trepan the teeth off? (Equivalent to using the rotary-table and slot-drilling.)

If you can swing it just turn the teeth off. Use a carbide fit for turning interrupted, or a hefty lump of HSS with not much rake to preserve the edge.

I'd use a angle grinder (or toolpost grinder) with a ttin cutting disk to take the teeth off. Tidy up with grinding disk before turning to size.
This could be done on the lathe or rotary table (with protection fom gringing dust) or a jury rig on an old wheel hub and grinder holder. The gear teeth may well be hardened.

Robert G8RPI.

+1 for angle grinder

Very many thanks everyone. That helps.

Martyn

I second Howard Lewis's approach. You need to know what interference fit the new ring gear will need and how wide it is, as a shoulder is required on the flywheel. Try a file on the teeth, if they are not too hard, then your lathe should cut them off with no problem, using carbide inserts such as TNMG. Remember to set up the flywheel the right way round for the shoulder.

Not bad, you only got about 30% angle grinder suggestions

Neil

Martyn, It seems your lathe is robust enough to handle the interrupted cut. I say chuck it up and have at it. Rig some kind of sheet metal deflector to clamp over your tool to keep the cast iron chips from flying everywhere.