This just fits on my Thing O Matic, so it can all be printed out in one shot.

This thing was made with Tinkercad. Edit it online https://tinkercad.com/things/0VOHtW4IryY

Print at a decent fill rate or it will collapse while snapping it together. Just snap the two long arms onto the front of the central odd shaped piece's legs and snap the final arm into the top of that central piece.