Summary

Almost every Ham with a 3D printer has to try their hand at a key/paddle at some point. Here's my contribution.

Tension is magnetic, and contacts are a pair of mouse button microswitches. Bearings (4X) are common hobbyist 625zz items. There are carriers for both large (10mm) and small (2mm) outboard tension magnets. I started with the 10mm ones but they were a bit too 'stiff' for my preference so I switched to the 2mm ones. The microswitches are widely available on various Chinese sites as well as Amazon, so they shouldn't be hard to come by. They have gold-plated contacts and are rated for 80 million operations. By my calculations, that equates to about 1500 years at 25wpm continuous.

I printed the base in ABS (eSun) and the levers in PCTG (3D Fuel); personal choice only, most any material would likely work fine.

The left and right levers are actually identical; just modeled them separately for whatever reason.

I have included both the STL files as well as the original (Autodesk Fusion) CAD files.