K31-compatible Sillypistol plunger rod

prusaprinters

The Sillypistol is currently a pre-production blaster for foam darts.  I wanted to make a version of this blaster for use in HvZ, so I needed to use a relatively weak spring.The existing plunger rod is wide enough that the K31 spring does not quite fit.This remix basically removes the corners of the rod to let this spring fit.  It's not terribly well done, but given that you'd be using a really weak spring, should still be plenty strong.If you're building a Sillypistol and you are using a spring heavier than K31 (which is most springs), use the original plunger rod rather than this one.