Apologies for raising this again

make an arbor that is held in the 4-jaw chuck and then put two short studs into the blind holes to use as drive dogs against the edge of two chuck jaws do you don't need to worry about it slipping on the arbor.

From a position of absolute ignoramce, would this suggestion have any merit? I understand that you want to remove redundant teeth, without doing intermittent cuts. Being a non-engineer, I would get my trusty angle grinder with a cutting disc and remove each tooth individually and THEN put the fkywheel in the lathe to clean up. How close to the teeth roots you cut would determine the interrupted cut required.

Someone better qualified will be along shortly with the correct way of doing it.

rgds

Bill

Martyn, I can understand what you are trying to achieve, but not why you are trying to achieve it. I'm not familiar with the details of the Austin 7, but I presume the gear ring is normally hidden within the bell-housing and therefore invisible to the naked eye.

If your intention is simply to prevent a mash-up if somebody tries to use the electric starter, wouldn't it make better sense to simply leave the starter motor unconnected? It would be a simple matter to make some sort of insulating bush for one of the connections in the starter circuit, which would be invisible to all but the most determined of observers.

George

If it were mine I would drill your holes through and bolt it to a faceplate and turn the teeth off. If you mill the teeth off you will bash the guts out of a milling cutter and mill spindle bearings so might as well do it on the lathe and bash the guts out of a lathe tool and lathe spindle bearings. I doubt you will do any damage to either lathe or mill whichever way you choose to go, machine tools are designed to take a bit of abuse, spend a few years in industry and you would see them being abused on a daily basis, if industry were too precious about their machinery they would never make any money.

Attach the flywheel to a faceplate as you suggest but turn the teeth off with a trepanning cut so no intermittent cut. In effect you are cutting off what amounts to a thin 'ring gear'.

Edited By Nick Clarke 3 on 19/01/2020 14:31:37

Since hundreds of thousands of these cars were made, surely you can find another flywheel?

If you must get the teeth off the one you have, if it were me, I'd grind a few teeth off to make room for a saw blade width. Then cut the major part of the rest of the teeth off with a bandsaw. Mill the rest off to a clean diameter by mounting it on a pivot pin and rotating it past a 1/2" or larger dia cutter. Just food for thought.

I would drill 4 new holes through the flywheel at 90 increments and clamp it to your faceplate. Unless it's a late flywheel (with the conventional lined centre plate) these holes could be covered by the clutch lining when the motor is re-assembled. I have machined several A7 flywheels either to lighten them or to machine the register for a shrunk on ring gear. A7 flywheels are made of a pretty tough steel, so it's worth making sure that it isn't going to shift while you're machining it.

Edited By Stueeee on 19/01/2020 15:17:59

I look for a picture on your forum whit no picture.i would suggest fitting boss where it fits to engine trying to keep it central better if there was hole in centre of the flywheel to work from. and grip in four jaw to centre. but remove the teeth with anglegrinder

Might be wrong but I think that flywheel maybe quite hard steel. Maybe you want to do this job just because if you do not it will bother you. Like I should have done it grr.

I agree with Jeff's suggestion, why not just get a refurbished flywheel, probably with a ring gear shrunk on, then you will be able to start by bump starting, crank handle and electric start. You wont have to worry about the lathe or mill, the teeth might be flame hardened on the old flywheel.

There's one on eBay, 4 hours to go £25, 0 bids, if you are quick.

Neil

I wouldn't subject rotary table gears to that sort of treatment especially with the extra leverage that the height of a three jaw chuck gives. If the table has 4 tee slots bolt the flywheel direct to it using the 1/2 BSF holes, if it's a 3 slot table that leaves you your faceplate idea as the best bet.

Martyn,

For me Cornish Jack has outlined a completely practical solution without the need to hammer the guts out of any machinery. The finishing cut(s) to remove the residual roots should be at slow revs with a heavy depth of cut to remove them like a hard skin on a casting.

I also think you will need 4 through bolts [at least] to clamp this down to a faceplate to prevent things moving about with vibration

Regards

Brian

Clamp the flywheel to the mill table then with use of x and y hand wheels roughly mill off the teeth. Make a mandrel to fit the bore with a flange on the chuck side that has two or one drive slot that the stud can be driven by and a nut or washer and bolts on the end. Then finish turn on this.

You may think it daft to try to mill round a circle with x and y hand wheels but you may be surprised how easy it is and how close you can get.

Here is a scary idea, mount the flywheel onto its crankshaft, then turn it between the centres of the crankshaft. If you use fine cuts, I wouldn't see that it was a problem turning the teeth off. My old Boxford has been subjected to far worse when I turned a complete crankshaft with 1.5" throw on each journal !

Cornish Jack is on the money. Either cut the teeth off by hand or set up on a face plate and rig the grinder as a toolpost grinder. BUT as others have asked WHY take the teeth off ?

Noel

Noel,

I wouldn't chop the teeth off anywhere near a lathe, think like the late John Stephenson. He wouldn't have mucked about, do the brutal bit in a vice and then clear up the mess later using a lathe.

Martyn must have his reasons for wanting to do this, I wouldn't question them.

Regards

Brian

No, JS would have welded up the gaps between the teeth and then skimmed it to look tidy. The heating and subsequent cooling from the welding would also mean the teeth were no longer hard as witches bits. 

Edited By JasonB on 19/01/2020 18:44:05

So he would Jason, I hadn't though of that.

Brian