Simple Helical Focuser for Astronomical Telescopes

This needs to be printed with fine layers, try 0.2mm.  Use the test prints first (or even shorter slices in your program) just to be sure it has nice action.

I might recommend a slightly taller layer height for the inner screw, to prevent the layers from interacting as much between the two pieces.

 

Bill of Materials
-PLA, black (or spray the inside black)

-Plumber's/PTFE tape for smoother action

• #10-24 nuts, 2-4x
• #10-24 thumb or socket head screws, you really want nylon for these.

OR

• M4 nuts and thumbscrews/socket head screws

AND

• Same-sized screws to bolt this to your telescope project.

I've printed half a dozen of these, and minute differences in filament, layer height, printer calibration can cause big changes in how well it works.  Worst case, re-print, sand, or CAREFULLY use hot water to deform the plastic. (With care that the base and eyepiece hole don't deform)