Changegear Calculators

• Boley & Leinen LZ4P Change Gear Calculator: a tool for calculating change-gears for threading on the Boley & Leinen LZ4P.
• Harrison M300 Change Gear Calculator: a tool for calculating change-gears for threading on the Harrison M300.
• Mini-Lathe Change Gear Calculator: a tool for calculating change-gears for threading on the 7x12 mini-lathe.
• Harrison M250 Change Gear Calculator: a tool for calculating change-gears for threading on the Harrison M250.

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.