Parting Off Between Centres

[jackrae]

Daft question perhaps but here goes.

Motor armature is being turned between centres and I then want to part off a piece at the tailstock end (to shorten shaft). Then, to complicate matters I want to centre drill the new free end to retain the ability to turn between centres.

OK we fit a fixed steady to the headstock side of the parting cut and then go to it.

This obviously won't work since the job will collapse at the point of parting.

As far as I can see I'll need to fit a 4-jaw chuck after the centre-turning operation, fit a fixed steady at the outboard end (inside the cut off point of course), part off and then centre drill.

Or is there another way

Opinions - ideas - critiques welcome

jack

[Tel]

That's about the way I'd tackle it Jack, there might be other ways, but I don't know 'em.

[alanstepney]

Ditto.

[JohnP]

I guess it depends how much you want to remove from the shaft. I did something similar, but only a few mm, by deepening the centre and then using a half centre to allow facing the end of the shaft down to the new length.

Regards,

JohnP

[IP]

What about setting up with the fixed steady nd drilling a plain hole up the shaft such that it will still be visible when the shaft is shortenned.

Then use the milling machine to trim the shft itself set up on 'vee' blocks either in the horizontal plane.

Then set up vertically with Vee blocks and angle plates and produce your centre hole by co-ordinate drilling.

Sounds copmplicated but its not and it does work, the advantage being that the shaft can be clocked to make sure its square.

Worth a thought maybe......leave it up to you.

Regards,

IP