Crooksz_Rocketz
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- Aug 25, 2015
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Good afternoon fellow rocketeers - I have a design question regarding fin fillet size. My current build uses 8.5" outer diameter sonotube wrapped twice with 10 oz fiberglass as the airframe. Fins are TTW to a 4" MMT. The fins are 33.5" root edge, 14" height and about the same tip chord. I am wondering what size fin fillet I should use. I've heard on forums that the fillet radius should be approximately 4 to 8% of the root chord but wanted to check if that's appropriate. 8% yields a 2.68" radius fillet, 4% yields a 1.34" radius fillet.
The fins are 0.5" baltic birch 9-ply and I will glass over the fillet and fins with 1-2 more layers of 10oz fiberglass after the fillets have cured. Using RocketPoxy for the fillets.
Also, the rocket will end up weighing approximately 100 lbs. Hopefully I didn't miss any details for your recommended fillet size!
Thanks!
T.J. Crooks
The fins are 0.5" baltic birch 9-ply and I will glass over the fillet and fins with 1-2 more layers of 10oz fiberglass after the fillets have cured. Using RocketPoxy for the fillets.
Also, the rocket will end up weighing approximately 100 lbs. Hopefully I didn't miss any details for your recommended fillet size!
Thanks!
T.J. Crooks