OpenRocket is telling me to make tiny fins for a long rocket

[finspin]

I'm glad you got it back, battle scars and all! Did you do a postmortem with your team? I like 8d with 5why at d4.

Not yet. Initial blame has been placed on a bad gasket. I know very little about the propulsion side of things, but my pet theory is that the chamber pressure may have been too high due to a fill issue, contributing to too-high thrust and burnthrough. I think this because the off-the-rail speed I calculated from video footage was much higher than predicted based on the rocket's weight and thrust curve. But that may be totally off-base from basic propulsion knowledge.

 

[Hobie1dog]

so it ruined your airframe and motor?

 

[charrington]

Not yet. Initial blame has been placed on a bad gasket. I know very little about the propulsion side of things, but my pet theory is that the chamber pressure may have been too high due to a fill issue, contributing to too-high thrust and burnthrough. I think this because the off-the-rail speed I calculated from video footage was much higher than predicted based on the rocket's weight and thrust curve. But that may be totally off-base from basic propulsion knowledge.

Good recovery even when your motor cato'd! Impressive! Figure out what you need to correct and launch again.

 

[Igotnothing]

This is the best example I've come across for why the cardboard cutout method should *NEVER* be used to estimate CP. It very reliably estimates a CP forward of the actual CP; in a rocket with pretty marginal power anyway putting enough weight in the nose to put CG ahead of that estimate means you're too slow off the rod for the fins to matter.

The cardboard cutout method should be decapitated, its mouth stuffed with garlic, a stake driven through its heart, burned to ash, and then buried at midnight at a crossroads.

Tell us how you feel, Joe!

 

[kavy8]

Are you from UCLA? I think I remember seeing this rocket at SAC. Hybrids were a gong show last year, we are taking our hybrid to Launch Canada instead this year because of all the logistical issues the hybrid teams had at SAC