Second attempt at this flight adds 20 more motors to first stage to boost acceleration and fun.
This project is now the HellBoy70
Description of second flight starts on post #69.
The Hell Boy (sustainer for this project) is a PoleCat Rocketry 5.5" Fat Man kit modified for clustering. Design is a 2x upscale of the Estes Fat Boy.
It has flown 6 times single staged on 19x 24mm motors, mostly Estes D12 and E9 engines. Each time fired by a flashpan and firing all motors.
First pic below is it going up on 19x E9 engines at LDRS this summer. I love the bright glow of burning illuminated particles in the smoke trail and the quiet hiss of all those motors.
TRF thread: http://www.rocketryforum.com/showthr...-motor-cluster
Always wanted to stage this beast.......
Time and Place: Planning to fly this 50 motor 2 stage project at the 11/3/12 CMASS Amesbury, MA launch.
Details: Two stages, each fired by taped-on flashpan method I have used previously, 31x motors first stage, 19x motors second stage - pictured below.
The sustainer is the Hell Boy on 19x C11 motors. (8.2 lbs with these motors)
Stage 2 ignition and dual deploy recovery fired by Featherweight Raven Altimeter.
Booster would be a one-time use part with tube fins built around 19x D11-P and 12x C11-0 motors. (estimated weight 3.3 lbs)
Stage 1 ignition: Fired by flashpan at the pad
Attached is a screen shot of a sim done at webalt.markworld.com. Other sims done on this site correlated well to actual past Hell Boy flights.
> Distances are in meters and weights in grams
> Staging is at 130+mph and 130+ft altitude
> Apogee is about 1200ft and recovery is dual deploy
Flight safety measures:
> Safety person ready on fire extinguisher to hose down booster when it lands - this is a precaution due to the number of BP motors, as there are no delays or ejection charges smoldering should be minimized.
> Another safety person on RC transmitter ready to fire an extra safety ejection charge to separate NC and deploy sustainer recovery system if flight is not nominal. No action would need to be taken by RC safety person unless sustainer trajectory became a concern. RC setup is the Hitec Optic 6, which is digital 2.4GHz. It's supposed to be immune to channel conflicts and has worked well in a number of RC flights. Have an RC relay for receiver which has successfully fired ematches repeatedly in ground tests.
> Use of Raven logic to prevent 2nd stage ignition if safety criteria are not met. From the Raven manual: "A deployment channel is triggered when all of the checked flight events are true."
1) Set timer to 1.8 sec
The other three logic settings are the safeties:
2) Vertical speed > safety threshold (80% of sim)
3) Altitude > safety threshold (80% of sim)
4) Baro pressure decreasing (going up)
All four logic conditions must be true at the same time for the second stage to fire.
This should be a very fun flight. 50 motors total, all BP, nearly a full I total impulse with two flashpans.
Makes me smile thinking about it.