Author Topic: Change gear charts for metric C2 mini-lathe - Imperial and Metric threads  (Read 2316 times)

Offline spuddevans

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Hi folks, last year before I moved house and lost my workshop, I had a little project to do which needed an Imperial thread. This posed a little problem for me as my little Mini-Lathe (Seig C2) was a metric leadscrew, and I was too tight to buy an imperial leadscrew and change gear set just for this one project.

I had read before that it is possible to screwcut an imperial thread on a metric lathe ( or vice-versa ) with many threads being accurate to under 0.5% error, so I set about researching and building a chart. Some of the imperial TPI's have a 1%Err but even with that, unless you are using a really long imperial nut, the error shouldn't create much of a problem.

My heartfelt thanks go out to Marv for his wonderful Change Gear program which did all the math for me, and I made up the attached charts. I made a Metric one as well as the supplied chart that came with the Lathe is far from comprehensive.

So I just thought I would share them with you, just in case there is anyone else out there with a C2 (although I think they will apply to the C3 and C4 too, not sure about the C6)

Hope this is in the right place, If  not I apologise in advance Mod's/Admin's  :slap:

Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME