Polargraph DrawBot Spool v2
The first ones I designed worked okay - but would sometimes pop apart. This is a single piece version that has several holes through the center of the spool so you can fit your thin monofilament line through it.
The first ones I designed worked okay - but would sometimes pop apart. This is a single piece version that has several holes through the center of the spool so you can fit your thin monofilament line through it.