Bullshit Grinder (AKA Trammel of Archimedes)

I had one of these as a kid, it was made of wood, I thought I would try making a printed version. It's an interesting toy that converts linear motion into rotation (or vise versa). Makes a cool desk toy/fidget.

It is fully printed and the base comes in four versions.

-Clean

-Embossed

-Hexagons

-BS

Printing instructions

The included Gcodes include all the parts you need to assemble 1 grinder.

I would recommend NOT using mat filaments as the higher frictions from the texture prevents the parts from sliding properly. If you must use mat filament, the trick I found was putting a tiny drop of PTFE oil (or similar) on the shuttles, it runs smooth after that.

The ones I printed in Glossy filament slid like butter straight away.

If you slice your own files, 10-15% infill is plenty

NO supports

For 1 grinder, you need:

• 1 Base ( choose 1 from the 4 options)
• 2 shuttles
• 1 shaft
• 3 c-clips
• 1 pin
• 1 knob

Assembly

Assembly is pretty straight forward, look at the photos for reference.

You should be done in under a minute and everything should run pretty smooth straight after assembly (and even better after a bit of use).

just make sure you insert the shuttles in the base before you connect them to the shaft.

Grind away!!!