It is easy to see the rpm variation potential now that slip is eliminated between the drill and the PIE’s wheel. For testing purposes, I have braced the drill with a piece of metal so it wouldn’t keep pulling it back and causing speed variations since I was not holding it steady enough.
As I continue the build, I still have not decided on a motor to power it. I do not want to commit to any particular motor design or speed, before doing some initial testing. There is still more work to do before I get to that point, at which time I will post those results here as well.
I am certain of is that if the PIE 2.0 becomes much more powerful, the whole unit will need a redesign so that it does not tear itself apart!!
I am also considering installing some very light weight springs to keep the weights from folding inward when it is not running. When that happens, the assembly can jam and not turn, it is as close to a “backfire” as the PIE 2.0 can have. The springs need to weak enough not to affect operation, but strong enough to do the job. I made it work with rubber bands, but they certainly won’t last long. It is something to think about.
Addendum 6/11/2020: As I was thinking about the possibility of adding some sort of spring (rubber bands work well) I noticed a spring clamp in my toolbox. EUREKA!! That is most likely the answer, a torsion spring! Like a mouse trap spring, the torsion type spring might be exactly what I need to keep it from “stalling on startup” without applying enough force to change how the PIE 2.0 works!!!