Hi Wolfgang,
Neil has put data in the table to cut imperial threads using a 2mm pitch leadscrew. You just need to factor in the 3:4 difference in ratio and change one of the gears to suit. Another way to look at it is to multiply the thread TPI value you want by 3/4 (0.75) then use the entry from the table for the 2mm pitch leadscrew corresponding to that value. For example if you want a 24 TPI thread. 24 x 3/4 = 18 so use the entry for 18 TPI on the table for a 2 mm leadscrew.

Les.

I have had nightmares about this!

There is little information out there that is definitive but it appears the majority of mini-lathes have 1.5mm pitch leadscrews but some have 2mm pitch.

But… when I wrote the article I produced tables for both metric pitches, so I've uploaded them to a pdf (with the tables in handy print out and laminate style!) linked to by the article here:

**LINK**

I hope that helps,

Neil

P.S. an odd situation – a 1.5mm/2.0mm metric leadscrew fitted with a handwheel with a 60/80 division graduated collar will give you better 'thou' accuracy than anything you can fit to an imperial leadscrew (e.g. the 64 division wheel I have fitted to my 16 tpi leadscrew)..

With an instinctive premonition of doom, when I ordered my (metric) Australian C3 minilathe I also purchased an imperial leadscrew as an 'optional' extra. It came with a whole bunch of new change gears and indexing chaser. It is a pita to swap but well worth the additional $110 (2006)

* Danny M *

Edited By Danny M2Z on 27/06/2014 17:15:58

Neil.

Thanks for the article and gear tables, but some combinations could do with a bit of a tune-up to squeeze a bit more out of this handy little lathe. I downloaded the NThreadP program from the lathes.co.uk site and it seemed to better some of the gear pairs shown in the charts.

Cheers, Martin.