Pinwheel app doesn’t have my arrow?


Well Known Rokslider
Nov 28, 2021
I was really just hoping to confirm my arrows were stiff enough. So I got the app and then bought the mod to get all the arrows and I couldn’t find my arrow.

I have CE d-stroyer piledriver arrows 350 spine cut to 27.25 it’s 11 gr per inch. I want to put either 75 gr inserts or 100 gr inserts. With 100 gr points.

Bow is Hoyt helix turbo 28 in draw @ 70 lbs
Ibo is 349 axle to axle is 31 brace height is 5.875

Mighty Mouse

Well Known Rokslider
Jun 21, 2019
Just choose another shaft make/model that has similar specs and manually adjust the gpi. My version of the app has Carbon Express Piledriver 350's listed at .345" static spine and 10.4 gpi. Selecting that shaft and manually adjusting gpi to 11.0, I got the output below with your listed specs, a 75 gr insert, three 7 gr vanes, and a 9 gr nock. The app shows .039" weak (.306" dynamic vs .345" static), but your actual arrow would be .033" weak because its actual static spine is .339".

gpi doesn’t matter in qSpine's dynamic spine calculation. You could re-run it with an ultralight shaft (e.g., GT Airstrike 340) at the same length with the same front/rear component weights and you would get the same calculated dynamic spine.

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