Looks great, Tim! I have printed with ABS which I hated due it's problem with shrinking when it cooled. I've been printing with PLA for some time now and love it. I recently purchased a roll of PETG and can't wait to try it out. I also want to get into flexible filaments like TPU and Ninjaflex.

I've posted a second version that doesn't have a launch lug attached.

Future versions include an integrated 1010 rail guide and another that will have fins that have a diamond airfoil that will allow it to fly supersonic with little problem.

This fin can as well as other versions really needs to be flight tested before I start selling them.