ACME fin can recovery questions

Hello i am building a 54mm MD rocket designed to fly on a J to 10100ft I'm wondering if i should use a smaller parachute and no drogue (drogue less) for recovery of course this rocket is duel deploy all fibreglass and i plan to use a Adept 22 if there is anything i could do better pls let me know...

You've provided way too little information for anyone to be able to help. Smaller chute, than what? What is the recovery weight? What is your target descent rate? Or for that matter, what will it be landing on? Soft ground or hard dry lake bed?

Which J? How does it sim out? Is >10000ft the goal, or are you just looking for what you can get, or are you trying to maximize altitude, or are you trying to hit 10100ft as close as possible? What is your waiver limit?

I'm assuming you are L2 and this is not your cert rocket. If it is your cert rocket for L2, then we can provide advice of course but we are not the people you should be asking!

Without details, you won't get usable answers.

Regardless, welcome to rocketryforum!

Gerald

All fiberglass small parachute and let it fall like a stone. Thats the beauty of fiberglass.

M target decent weight was 10-15mps but i was wondering the ACME fin can could take 16-20 i don't want to lose it regardless I'm going to use a tracker.

The recovery weight is 4ish pounds

And it is on grass

Normal descent rate for landing on grass might be 20fps, +/- 5. 10-15mps is getting dangerously fast for whatever it might land on. Heck, it might not be terribly much faster than that range if dropped drogueless all the way to the ground. I think you need to re-assess the descent rate from a safety perspective. For that matter, going much below 15fps descent rate under main can cause stability issues with the main inflation as well as increasing the odds of the rocket being dragged across the ground in a breeze (the latter is more an issue with larger rockets).

Gerald

G_T said:

Normal descent rate for landing on grass might be 20fps, +/- 5. 10-15mps is getting dangerously fast for whatever it might land on. Heck, it might not be terribly much faster than that range if dropped drogueless all the way to the ground. I think you need to re-assess the descent rate from a safety perspective. For that matter, going much below 15fps descent rate under main can cause stability issues with the main inflation as well as increasing the odds of the rocket being dragged across the ground in a breeze (the latter is more an issue with larger rockets).

Gerald

Click to expand...

Yes i agree i have made my own parachutes and now the descent rate is only 10meters per second but i plan to release the main pretty low like 800ft maybe...

10 meters per second is too slow for an apogee deployment descent rate from 10 kft. You want the initial descent rate to be 2 to 3 times faster: 20-30 m/s.

Conversely 10 m/s is 2 times faster than the main descent rate should be: 5-7 m/s is what you should aim for. It not how much the rocket can take, it's how much the person the rocket accidently hits can take without serious injury.......

Bob

bobkrech said:

10 meters per second is too slow for an apogee deployment descent rate from 10 kft. You want the initial descent rate to be 2 to 3 times faster: 20-30 m/s.

Conversely 10 m/s is 2 times faster than the main descent rate should be: 5-7 m/s is what you should aim for. It not how much the rocket can take, it's how much the person the rocket accidently hits can take without serious injury.......

Bob

Click to expand...

Got it thanks and the rocket is duel deploy...