Mini Lathe Thread Cutting Change Gears

This is a set of change gears designed specifically for a Harbor Freight 7X10 or 7X12 mini lathe. I do not know if they can be used on other brands of Import lathes like Vevor, Grizzly, Wen, etc. 

These gears are all 8mm thick and feature a 12mm bore with a 3mm keyway, both of which have been toleranced to account for slight material shrinkage during printing. 

By changing the arrangement of these gears within the removeable side cover of the lathe, different thread pitches can be cut. For example, using the 40, 65, and 50 tooth combination will result in a pitch of 20 threads per inch while cutting using the power feed screw. Reference the side of the lathe or user manual to find the change gear combination required. Depending on what your lathe came with, you may need some kind of spacer(s) and keys. For the spacer, a cylinder 8mm in height with a 12mm internal diameter should work, keys can be made from some 3X3mm stock (If you don't already have these included in your lathe).

I have had success operating with PLA gears, so there should be no issue if you use PLA or even something stronger. I would also recommend using more than one shell layer to increase the strength of the teeth.