My printer has some backlash on the X or Y axis, my circles are ovals.
Attaching the pulley system to the wire was not easy, lost a pulley in the process.
The support arm is bulky and ugly, probably way overbuilt.

PLA's plastic deformation point is 60-65C. The SMA wire has a transition point of 70C. I was worried that the wire would slice through the PLA pulleys very quickly, but after a dozens contractions there's no obvious damage. This is great as I'll be able to test with printed parts rather than printing, casting to high temp urethane, then testing. Casting parts is very time consuming, this is a big boost to the project.