I loved this rocket as a kid and was lucky enough to have huge open fields to fly them in and did not lose this rocket the 1st time I flew it. I had started getting parts together to do a fiberglass min dia rocket and I am thinking of going with the classic Estes Astron Sprint. But I am pretty uneasy with the fin length and RocSim shows it stable but will over Mach. Those fins are really long and flutter is a big concern. So tossing this out there for thoughts. What say you?
Considering doing an Estes Astron Sprint Upscale to 54mm Min Dia
- Thread starter bchaltraw
- Start date
IMHO, it's not a Sprint, without the boatttttt tail. 
Just looks like a tube with Spitfire wing shape fins.
Roy
Just looks like a tube with Spitfire wing shape fins.
Roy
Would definitely run some flutter calcs.
I agreed, I was thinking of using a boattail retainer.IMHO, it's not a Sprint, without the boatttttt tail.
Just looks like a tube with Spitfire wing shape fins.
Roy
Then I will not have the joy of trying to make the cardboard one of the original the right shape by dragging it over the edge of the desk as I did back in the 80s!
That looks awesome! I have a GPS, and all of the dual deployment items, the Min Dia AeroTech mount, thinking G10 Fins or Carbon, and a Fiberglass body. Nose Cone to be right I may have to use foam and build myself or I have club members with 3D printers.
If you're going that far, maybe think about foam core glass/carbon skinned fins that taper in thickness from root to tip.
Making progress on this, decided to not go Min Dia and go 4" instead. That makes it so every engine other then a massive one does not push it over Mach. This will make it so I can do dual deployment with my already built e-bay and not have to worry so much about fin flutter. With a J140 should go around 8500 ft, which is plenty far. Only engine that would push over Mach is a K570 so I should be good to go. Next up ordering parts!
