Aerodynamic arrow testing?

[Del the cat]

I came across this Youtube video about rocket stability, which has obvious implications for testing flight arrows, including an interesting stability test method.
The first 3 minutes are a bit unnecessary:-
Maybe some discussion points/comments?
https://www.youtube.com/watch?v=qCzF9OfYahc
Del

[sleek]

Great, now I'm going to be outside with an arrow on a string spinning around like a control line aircraft model.

[Selfbowman]

Me to!!!

[Selfbowman]

Del do you hang your 2 # weight at balance point when spinning an arrow? On flight arrows that can change pretty drastically depending on the taper?

[Selfbowman]

Del the interesting thing I noticed about this experiment is no matter what kind of arrow the string ended up tied about 1-1/4 inch forward of the balance point. Broadhead or flight arrow front of center or to rear of center of the arrow. I’m not sure what this means but it might bring in centrifugal force somehow.