I remixed this to use M5x20mm button head screws, as I didn't have any M5x30mm bolts.

For hardware, you'll need 4 x M5x20mm button head screws and 8 nuts.   Be sure to tightly screw one nut onto each M5x20mm screw (adding some Lock-Tight is optional, but helps keep the nut at the top of the screw head).

Only the Knobs should be printed with supports.

You'll need to print 2 x Arm1 pieces and only 1 x Arm2.

I've added a smaller base which is printable on a Prusa Mini/Mini+ (but to do so, you'll have to set your Skirt Height to zero in PrusaSlicer).

Note:  Arm2 has inbuilt sacrificial bridges which you'll need to clean up by running a screw through the holes before completing your assembly.

Assembly Tip:  While screwing together Arm2 & Arm1 pieces; you can temporarily use something like an extra nut, to help push the nuts into place on Arm2 so that the screw can reach it.

2026-05-25:  added another knob with extra clearance.