Mini-Lathe Change Gear Calculator

This tool can calculate possibly alternative gears that can be used to cut a particular thread on a 7x12 mini-lathe like my Sieg SC2. It works with either a 1.5 mm pitch leadscrew (the default) or a 16 TPI one. It is heavily based on the work of Al Harral; I just thought it would be nice to have a web-based alternative for those (like me) who don't use Windows very much.

The code is based on Al Harral's GEARS.BAS so I certainly can't claim any credit for the intelligence behind this code: I simply ported it to javascript (via a python version as I find python a bit easier than javascript).

I am a hobbyist metalworker and woodworker. I work as an electronic design engineer and spend most of my working days in front of a computer so I enjoy having the opportunity to use my hands and make things in my spare time. I particularly enjoy making tools as I can then use them on other projects. This website showcases some of the things I've made.

This website is free and ad-free, but costs me money to run. If you'd like to support this site, please consider making a small donation or sending me a message to let me know what you liked or found useful.

Please do get in touch if you notice any issues on the site or can think of anything that would be a helpful addition or improvement.