Post by Rocketman on Sept 5, 2005 2:12:28 GMT -6
Last summer I decided to build a mid power rocket. I ned my rocket Skyfire. I received the parts quickly from Red Arrow Hobbies.
www.redarrowhobbies.com
After a day or two of assembly, mostly waiting on the glue to dry, I decided it was ready to fly. Unfortunatly this first flight would be the last
The rocket roared of the launch pad reaching about 1600 feet. It took ten seconds to hit the ground after reaching apogee.
d=v0t + 1/2 at^2
v0t = 0
d=1/2 a t^2
0.5 x 32.2 x 10 x 10 = 1610 feet
The black powder ejection charge at the forward end of the motor was of an insufficient amount, and the ten second delay was much too long. Even had the ejection delay been shorter, the amount of BP would not have been enough to deploy the parachute.
Skyfire XR1 sadly was completely destroyed. I did manage to salvage the motor casing without any damage.
Now over a year later, I'm preparing for launch. This time I have modified my initial design by separating the airframe via a black powder charge. This time I will be using a Missile Works RRC2 altimeter. It has redundant apogee firing one second after the first firing. The rocket is simply prepped on the pad by selecting from a number of switches on the altimeter. Event one can fire at apogee, and event two can fire at 1000/800/500/300 feet (switch selectable).
The end of the airframe at the separation joint has a 1/2 PVC cap fixed to a birch bulkhead. A special type of igniter is place down into the PVC cap. Next the PVC cap is filled with a sufficient amount of black powder, and taped shut with paper tape. The altimeter is set to the desired configuration. Then the connections from the altimeter to the ejection charge igniter are made, and secured. The upper part of the airframe containing the altimeter, and nosecone is mated to the lower part. It's basically 3...2..1.. liftoff at this point.
The RRC2 altimeter allows me to test igniter continuity, and to test BP charges. Below is an animation of a test I did.
From the animation you can clearly see that the amount of charge is a bit too much. Iforgot to secure the nosecone, it landed about 120 feet away. However, no damaged occured from this test.
This design utilizing the onboard avionics ensures that the parachute will be deployed. The RRC2 is a well trusted, and reliable piece of hardware for amatuer rocketry.
I'll will be adding some additional pictures to this post. So check back later.
I enjoy being involved in numerous related activities.
www.redarrowhobbies.com
After a day or two of assembly, mostly waiting on the glue to dry, I decided it was ready to fly. Unfortunatly this first flight would be the last
The rocket roared of the launch pad reaching about 1600 feet. It took ten seconds to hit the ground after reaching apogee.
d=v0t + 1/2 at^2
v0t = 0
d=1/2 a t^2
0.5 x 32.2 x 10 x 10 = 1610 feet
The black powder ejection charge at the forward end of the motor was of an insufficient amount, and the ten second delay was much too long. Even had the ejection delay been shorter, the amount of BP would not have been enough to deploy the parachute.
Skyfire XR1 sadly was completely destroyed. I did manage to salvage the motor casing without any damage.
Now over a year later, I'm preparing for launch. This time I have modified my initial design by separating the airframe via a black powder charge. This time I will be using a Missile Works RRC2 altimeter. It has redundant apogee firing one second after the first firing. The rocket is simply prepped on the pad by selecting from a number of switches on the altimeter. Event one can fire at apogee, and event two can fire at 1000/800/500/300 feet (switch selectable).
The end of the airframe at the separation joint has a 1/2 PVC cap fixed to a birch bulkhead. A special type of igniter is place down into the PVC cap. Next the PVC cap is filled with a sufficient amount of black powder, and taped shut with paper tape. The altimeter is set to the desired configuration. Then the connections from the altimeter to the ejection charge igniter are made, and secured. The upper part of the airframe containing the altimeter, and nosecone is mated to the lower part. It's basically 3...2..1.. liftoff at this point.
The RRC2 altimeter allows me to test igniter continuity, and to test BP charges. Below is an animation of a test I did.
From the animation you can clearly see that the amount of charge is a bit too much. Iforgot to secure the nosecone, it landed about 120 feet away. However, no damaged occured from this test.
This design utilizing the onboard avionics ensures that the parachute will be deployed. The RRC2 is a well trusted, and reliable piece of hardware for amatuer rocketry.
I'll will be adding some additional pictures to this post. So check back later.
I enjoy being involved in numerous related activities.