Black Powder Motor (Estes) Stand-ins

I developed this to act as BP motor stand-ins that would also allow me to add weight to them in order to match a full motor I want to simulate.

This way you don't have to handle 'live' motors or dirty used ones. (yeah, I know it's trivial but heck, I have a 3D printer, so....)

I found the 13mm motors too difficult to get a good thread working, so I just made that a friction cap.

Note: I have added the 29mm motor case.