Hi Ian,
Yep, your math is far more gooder than mine.
All the more reason to keep the engagement part of the cycle as short as possible.
The electro, or air acting directly on the cut might be closer to 10 ms getting us back to near 1/4" @ 150 FPM. (I hope
)
I don't know how to figgure or estimate the vel, of the hammer, but the material is .25" dia max (for now).
So the "time in matl" would be derived from that.
The toughest to cut is a copper/nickel alloy tube ... .25" OD.
Thanks Ian, much appreciated,
Russ