For me, nothing (except a benchy of course) screams "3D printed" as a print-in-place planetary herringbone gear. So what better to use as a 3D printer's door handle than this little gem of ingenuity?

There are two sizes (51mm and 42mm), the smaller one being flush with the door edge. I also chose more rectangular teeth style.

And for each there are 6 variants with different tolerances/clearances ("tol16" etc), the best one depending on your printer, filament and settings.

If the gears bake together and you can't get them loose, try more tolerance. If it wobbles much, try less tolerance. You probably have the right one if they are a bit hard to get moving at first but you can get them loose with a bit of force. Some breaking in usually gets it smoothly running.