Taig Lathe Threading Attachment

Demo video:
https://youtu.be/VILK6h7MCjQ


I wanted to cut threads on my Taig lathe without using a tap and die. I have seen different attachments that people have devised for thread cutting. I wanted to make one that doesn’t require any modifications to the lathe components and be relatively simple to install and remove. I also wanted the hardware components to be something that you can easily find at a hardware store.

This unit is not designed to be a power feed. As is, it is designed to be turned by hand.

The spindle gear is a friction fit onto the headstock pulley. I have added holes to it for set screws, but so far I have found that the friction fitment holds it solidly enough.

The bushings in the lead screw carrier are 3/8”x1/4”. You will need 2 of those.
The nuts used are ¼-20.
The threaded rod used is ¼-20.
The washers are ¼”.
The lock collar is ¼”.

The gears have a 14.5 degree pressure angle.
The spindle gear, gear A, gear B, and the leadscrew drive are