Lathe Change Gears - 9x20

If you have a 9x20 lathe then you know what change gears are, and if you bought a used 9x20 lathe some of those gears may have gone missing. These 3D printed gears can be used to replace missing gears. Even if you have the original metal gears, using one of two of the plastic gears can make for less noisy operation.

Includes gears with these tooth counts:

- *20-key

- *20-no-key

- *22-key

- *22-no-key

- 28

- 30

- 36

- 40

- 42

- 45

- 60

- 80

- 120

- 127

- These four gears are very small, so they have no text and a reduced key slot size. Since the key slot weakens a gear this small, I also provide versions with no key slot.

The nominal gear parameters are as follows (modified in two cases for the 3D prints as noted):

Thickness: 8mm

Bore Diameter: 14mm (print 14.05 mm)

Key Width: 5mm

Key Depth: 2.5mm (print 4mm)

Pressure Angle: 20

Mod 1

This was inspired by the Thingiverse project below, although all of the work here is based on new 3D CAD files I created:

https://www.thingiverse.com/thing:204587

The OnShape 3D CAD files for this are available here:

https://cad.onshape.com/documents/6972fa915e8bec8931a466e6/w/2222457e43a805ed2991d955/e/3dca93b88e1d3875dcdbeda5

Print instructions

Use the 3mf files provided, or . . .

Print face down (text side up). PLA seems to work fine.

- 60% rectilinear infill

- concentric top and bottom pattern

- perimeters = 6

- top/bottom solid layers = 5

- complete individual objects (when printing multiple gears at the same time)