Argh crimping those hundreds of terminals on that first set of machines made me so sad, and demolished my finger tips, so I just had to find an alternative!

https://github.com/euphy/polargraph/wiki/Building-a-Polargraph-from-a-vitamin-kit#connectors has some pics of the new connectors. They're great little things, though not cheap, and I wonder if they'll stop making them one day. If you have stiff enough wire, you can just trim the insulation off, and push-fit it into the aperture in the connector.

Because the stranded wire I use isn't very stiff, I use a very fine flat-bladed screwdriver to manually open up the wire "catch", and then slide the wire in.

The connection isn't indestructible, but one benefit is that it's super easy to fix if it gets yanked out.

Good luck!