A mostly-printed variable capacitor.

I don't necessarily recommend making this one, as I designed it around what I had, and it isn't perfect. This is more sharing for inspirational purposes :)

Uses two 100mmx70mm single-sided copper clad boards, a 1/4"x20 length of threaded rod, and m4 bolts to hold it together (and one for the set screw in the knob). Weird mix of metric and imperial, but that is what I had.

The bearing blocks rotate and are printed in once piece - I forget the tolerance, but it is fairly tight to prevent wiggling. I printed at .2 layer height.

The pieces that need to be threaded (the bolts/cap sliders/knob) are threaded except the set screw hole (as I was having trouble getting Fusion 360 to cooperate), but I went through all of them with taps to make them turn smooth anyway.

I had to shim some paper under the bearing blocks as my apparently my copper boards were slightly thicker than I measured.

The bottom copper board is super-glued to the base, and the top one is super-glued to the blocks it moves on. Just eyeball where they should be, leaving the top on a little over so the top board doesn't run into the solder joint of the bottom board.

Mine is doing 34pF-164pF.