Doing any threading on a lathe is a chore. Changing the gears can be way too much of a pain. So after esar saw Youtube videos including Clough42’s series on the Electronic Lead Screw project, they were inspired to do something similar.

For anyone unfamiliar, a lathe usually has a chain of gears linking the spindle/chuck to the lead screw that drives the carriage backwards and forwards along the bed. The gears can be changed to alter how far the carriage moves for each rotation of the spindle. For example, to cut the thread on an M6 screw, the gears would be setup so that the carriage moves 1mm for each rotation.

On this lathe, changing the gears involves two spanners, an allen key, and digging through the big pile of gears to find the four that the cryptic chart says are required for the desired ratio. It takes a good five to ten minutes and gets your hands covered in oil and grease.

An electronic lead screw replaces the chain of mechanical gears with an encoder that reads the spindle speed, a stepper motor or servo to turn the lead screw, and a controller to link the two together. Then the ratio can be changed instantly at the press of a button.

Rather than using Clough42’s implementation I wanted to create something more tailored to my lathe.

Read how the solution worked well on the newly reconfigured lathe in the post here.