clarke CL430 lathe

Hello everyone and hope i can have some advice.

My Clarke CL430 lathe cross slide nut has stripped the thread( bronze),

There are no spares from the company now as they have discontinued the model.

Measured the thread as 11.8mmOD and root dia 10mm.and its an acme.

I presume the actual size would be 12OD but checked every where am confused as sure its 13TPI but all seem to be 12 or 14 HELP.

I would be very tempted to speak to the likes of Chester or Warco & such like as they all sold  clones of your machine.Kevin

Edited By kevin laxon on 18/09/2023 17:29:10

I think all the lathe threads are metric, so are you sure the pitch of the nut is threads per inch?

Isn't there a dial on the handwheel - how's it marked?

13tpi would be a very weird choice for a leadscrew. It would give 0.07692" per rev of the handle, requiring some heavy math for accurate cuts.

I would guess (as John H suggests) its metric and 2mm pitch - which is 12.7 tpi.

… and for the sake of pedantic detail:

If the thread form is ACME it should be 29°

If the thread form is Metric Trapezoidal it should be 30°

Unfortunately, all combinations and permutations appear … both in reality, and in advertising !

MichaelG.

Edited By Michael Gilligan on 18/09/2023 20:01:22

The hand wheel will tell you the thread pitch. If it is 100 thou per rev it is 10 TPI, 12 thou would be 8 TPI.

If metric, 1mm would be a 1MM pitch thread,

So what is the hand wheel marked in?

This might be useful for reference: **LINK**

https://www.clarkeservice.co.uk/manuals/metal_lathes/CL430_Metal_Lathe_REV_3.pdf

MichaelG.

.

Edit: __ and more particularly, this

https://www.clarkeservice.co.uk/technical_information/metalworking/cl430-500m_tech.pdf

Edited By Michael Gilligan on 19/09/2023 09:05:26

Thanks ever so much tro all for taking the time to reply and give me help and advice.

joe