Is 1/8" ply too small for HP fins?

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rifleshooter

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I have some 1/8" ply for the kooky Striker AGM Quest LP upscaler I'm making with a PML tube. Rocket will be driven with a 38mm - 54mm RMS (flying the 38mm RMS under an adaptor until higher performance is required).

If I laminate with paper or glass, will 1/8" be sufficient, or is it time for me to start thinking G-10, or 1/4" ply or something?
 
My L1 rocket has 1/8 inch plywood fins that have no further reinforcement. The rocket has flown many times on H and I motors the biggest being an I211. That's my experience for what it's worth.
 
LOC's Caliber ISP has 1/8" 5-ply fins. That can handle 54mm J motors. Not sure how high of thrust.

Cheap 3-ply has less strength. I usually goto 1/4" 5-ply instead of the 1/8" because it is more readily available (Michael's Crafts).

Lots depends on the fin design. A wide fin spans require more strength to reduce fin flutter.
 
Thanks, guys. I think I'm going to try to build this one light as I suspect that the design is going to be draggy.

As I finish the design, I'll post a build thread.
 
One good thing is that the fin root is very long, thus stronger. One bad thing is that the thin part of the fin extends out pretty far. I bet you are fine through level 1, with reasonable thrust motors.

If you laminate with glass she will do J motors no problem. Fiberglass makes fins extremely strong and rigid in my experience - comparable to thin G10 - 12 fins.
 
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