I'm in the midst of creating a flywheel-based launcher for homemade pool noodle nerf rockets, I figured I'd post the cutting jig that I used. (jig cutter and jig flush)
The two pieces are separate for printability, and superglue together.
There is a slot in the jig cutter piece to use with a small hacksaw or similar.
The flywheel system is very much untested and somewhat conceptual, but I thought I'd post those parts in here anyway for context.
The author marked this model as their own original creation.