Clock wheels set up and dividing

I would like to make a large clock wheel. I havent started yet. I have an ML7 and a vertical mill An Arboga. I have an BS01 dividibg head with a 3 jaw chuck attached.

I will make the blank on the Myford, however if I transfer the blank across to the chuck to ghe dividing head I will loose concentricity. Is this a problem.? Do I need a milling set up on the Myford and a compatible diving system? Thanks, Roger.

The ideal way would be to use an MT2 arbor in the lathe then the same one in the dividing head. However if the dividing head came with the mill it might be a genuine Browne and Sharpe with a BS taper which is similar but not an MT2, I think. Check that option first.
If the arbor is being held in the 3 jaw in the lathe then first make sure it is truly centred using shims to compensate the errors in the chuck. Note this is checking the arbor not the blank after turning.
Knowing the arbor and the blank are both concentric you can use the rim of the blank to set the arbor in the dividing head and shim to get it true.

What you can't do is have a wonky arbor in the lathe and get a good result. Then even if it is good in the lathe you can't rely on the dividing head 3 jaw to be good.

If you carefully turn the outside of the blank concentric then cut the teeth you'll be milling away what you just turned. Why not do the whole job in the mill?

Common arbour is the best. But if not possible, then could you not mount the blank in the dividing head. Swivel the head so that the blank is horizontal and mill the outer diameter (and drill the entre). Then swivel back to vertical and cut the teeth.

PS. Don't forget that for a big wheel, you will need to mount the blank on some sort of backing to support it during cutting.

Edited By Peter Cook 6 on 17/10/2022 20:07:23

For generations, clockmakers did wheel-cutting in the lathe … using a milling spindle and an overhead drive.

Personally, I think that balances the form and function of the machine better than more ‘modern’ arrangements.

MichaelG.

.

Edit: __ This is, I think, about as close to right as you can get:

https://youtu.be/HEipLwJCasA

[ Part 3 of his 3-part series ]

Edited By Michael Gilligan on 17/10/2022 20:07:04