I'm considering the size and shape of the 3 fins for my Delta II 7925-10L. It's a 4" core transition to 5" on top with 9 strap-ons, each approximately 1.5" dia (BT-60 tube). total height is 65". I don't want it to be a high-velocity rocket and I'll be using a J135 for the core, six F-30's strap-ons 0.5 sec after launch, shed those, then airstart three G's strap-ons then shed the last three strap-ons. For the 3 fins, I'm using 3/16" thick abrasion resistant polycarbonate that by my estimate has a stiffness similar to 1/8" birch. The fins are through-the-wall and fiberglassed to the 54mm engine mount. I'm thinking to configure the fins as clipped deltas to avoid busting a tip during landing. Since the rocket has 9 strap-ons, seems to me this would add stability during launch (like tube fins). Am I wrong thinking this? I would like to keep the fins on the small size. Please advise and thank you,Richard Dierking