I made the original three switch design for my son who loves gears. It's worked fine for the past 3 months so I made a single light switch plate for my basement light switch.
I printed the whole thing out in 14 hours at one time in gray PLA. I used 20% infill which worked but didn't have the best surface finish. (the all gray picture above) In later runs I used 40% and that worked much better.
I didn't like the prison look for the light switch so I remade the gear and pinion using orange PET-G.
I noticed that the gears run smoother with the orange PET-G. So that's interesting. . . .
output as "fine" from onshape
The small gear and crank do not need to be glued together but I did anyway.
The crank and gear are held onto the light switch plate by an m3 screw. I sized the hole in the post so that it does not need to be drilled out. It does need to be tapped with an m3 tap.
Tap that hole
After you print this out and remove the supports. The post on the light switch plate needs to be threaded with an m3 tap.
The Pinion has to be in the groove before you put it on the wall. The holes in the bottom of the pinions are so you can sneak the bottom screw into the light switch.
If it gets jammed you might not have tightened down the screw enough.
Break all support off parts, sand the back of gears with 200 grit sandpaper for smooth operation
Glue the small gear to the handle using loctite 401 using the nubs as guides
Tap all the post holes with the M3 tap set
Before installation, tighten all gears onto light switch plate and check the back to make sure the bolt doesn't go all the way through.
!!!(IF THE BOLTS PROTRUDE OUT THE BACK OF THE LIGHT SWITCH; IT IS AN ELECTROCUTION HAZARD)!!!
Put a piece of electrical tape over the back of the post holes.
Make sure light switch gears operate smoothly. (I had to sand down the side of the pinion for smooth operation.)
Turn OFF power to the light switch, at the residences' circuit breaker.
Mount light switch plate to the wall with the pinion part pre-installed.
Mount gears to light switch plate.
Test for smooth operation, You may need to sand the gear teeth or sides of the pinion if the print was rough or stringy.
Turn power house power back ON at the breaker.