Piston KEY RING (wrist pin wire lock)

After extensive use the original wrist pin would fall out.

Added a wire lock to retain the wrist pin. I found I had to use the thinner wire lock with PLA, however PLA+ had no issue with either size. I may have also been aggressive when shoving it in. I'd recommend printing a spare. They print quickly, they're tiny.

I used havenoname's updated piston.