pendrin2020
Well-Known Member
- Joined
- Mar 4, 2018
- Messages
- 168
- Reaction score
- 43
So here's the story, we're in a competition to implement active roll control, and test it in a real rocket. At the suggestion of our NASA mentor, we're using cold-gas thrusters.
The implementation of that is still a rat's nest of unanswered questions, and pressing deadlines, so please for the love of god, don't go there...
Every section of the rocket has a very specific (very heavy) payload, and space for each has been minimized. Some payload items include:
1. 30.5ci 3000 psi HPA cylinder 1kg
2. high-flow pressure regulator 0.25kg
3. Pneumatic solenoids (x3) 0.75kg (total)
4. lots of plumbing hardware (weight included in solenoid total)
I've created the most accurate OR file I can possibly make at this juncture. The cg can be easily adjusted through the shifting of several payload items, so that's not an issue. The design was created to be flexible as components choices could change (components have been finalized btw).
The fin can is 30in long and is joined via a 9" coupler to the nozzle bay, which is joined to the forward payload tube by a 6" coupler. The 9" coupler is joined to the nozzle bay using epoxy, the 6" coupler is joined to the forward payload section using epoxy as well. The NC, Forward payload bay, and nozzle bay are secured together using machine screws. This is a single split recovery with a jolly logic dual deployment. All tubing is MadCow standard thickness fiberglass. Again, this is NOT thin-wall FG. All screw holes are backed by a threaded nut to provide compression and avoid relying solely on the threading of the fiberglass. In the diagram below, the payload items from left to right are:
1. thruster control avionics
2. HPA cylinder
3. Solenoids and regulator package.
4. the lower-most coupler houses a commercial tracking and recovery package.
The rocket is 7.2 kg before motors, and just over 78in tall. Our chosen motor is the Aerotech J800T. This is the largest motor the competition will allow us to fly.
Stability margin during flight is predicted to remain above one caliber throughout the flight. The heavy payload items have pushed the CG far forward, and have minimized the required size of our fins.
I have never attempted to loft THIS MUCH WEIGHT in a 3" package. Here's my question... given the diagram below, are there any red flags that you believe place the mission at risk? (Aside from the nature of the payload, and assuming that all payload items are properly secured against forces due to boost and recovery).
You think it'll fold in half? The damned thing weighs 15+lbs dry.
The implementation of that is still a rat's nest of unanswered questions, and pressing deadlines, so please for the love of god, don't go there...
Every section of the rocket has a very specific (very heavy) payload, and space for each has been minimized. Some payload items include:
1. 30.5ci 3000 psi HPA cylinder 1kg
2. high-flow pressure regulator 0.25kg
3. Pneumatic solenoids (x3) 0.75kg (total)
4. lots of plumbing hardware (weight included in solenoid total)
I've created the most accurate OR file I can possibly make at this juncture. The cg can be easily adjusted through the shifting of several payload items, so that's not an issue. The design was created to be flexible as components choices could change (components have been finalized btw).
The fin can is 30in long and is joined via a 9" coupler to the nozzle bay, which is joined to the forward payload tube by a 6" coupler. The 9" coupler is joined to the nozzle bay using epoxy, the 6" coupler is joined to the forward payload section using epoxy as well. The NC, Forward payload bay, and nozzle bay are secured together using machine screws. This is a single split recovery with a jolly logic dual deployment. All tubing is MadCow standard thickness fiberglass. Again, this is NOT thin-wall FG. All screw holes are backed by a threaded nut to provide compression and avoid relying solely on the threading of the fiberglass. In the diagram below, the payload items from left to right are:
1. thruster control avionics
2. HPA cylinder
3. Solenoids and regulator package.
4. the lower-most coupler houses a commercial tracking and recovery package.
The rocket is 7.2 kg before motors, and just over 78in tall. Our chosen motor is the Aerotech J800T. This is the largest motor the competition will allow us to fly.
Stability margin during flight is predicted to remain above one caliber throughout the flight. The heavy payload items have pushed the CG far forward, and have minimized the required size of our fins.
I have never attempted to loft THIS MUCH WEIGHT in a 3" package. Here's my question... given the diagram below, are there any red flags that you believe place the mission at risk? (Aside from the nature of the payload, and assuming that all payload items are properly secured against forces due to boost and recovery).
You think it'll fold in half? The damned thing weighs 15+lbs dry.