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- Aug 27, 2011
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Continued work on the Break Away recovery technique. As a fellow old fart, JPVegh, pointed out, turns out this is not an original concept. Estes CATO was similar.
Hold your breath, I actually PAINTED something before I flew it (although I couldn't wait to make the decals, so flew it without them. The decals were going to be "Mayday! Mayday!", "Gone Fission", "Separation Anxiety", and the nuclear symbol. One on each of the four fins (but let's not get into the 3 fin 4 fin argument, my retention system for this design requires 4 fins.)
This model has motor retention, a central "core" holds the engine, has a streamer, a nose pyramid/forward fin retainer, and squares at front and back to guide/position the fins/sidewalls. Still uses rubber band/burn band retention for the back of the fins/sidewalls.
SHOULD have gone with B6-0, but didn't have any and Hobby Lobby not open on Sundays (my only local source of motors.) Wasn't sure an A8-3 was going to lift this. It has balsa fins/sidewalls, papered on the outside of the sidewalls and both sides of the fins. Had 5 coats of paint (grey primer, yellow--- then white primer when the yellow looks bad over the grey primer:bang:, yellow, yellow again, then orange trim. Thought the yellow and orange would contrast better, when they didn't, put down red mylar tape "pinstriping")---- anyway, 5 coats of paint, so figured would be too heavy. Probably would have worked.
B6-4 put it up to, I'm guessing here, about 250 feet. Did NOT pop the nose, came down ballistic (totally unintended) but the sidewall/fins apparently worked loose enought to break up at 150 feet. All pieces came down within 75 feet of the pad, but even with the short grass, still took me about 5 minutes to find all 5 piece.
No "holy burnt fins, Batman" on this one (the central core handles the engine gases nicely.) My trifold motor mount stuck out enough to hang up the streamer--- which may have been a GOOD thing as had this deployed at 250 feet I NEVER would have found all the parts. I'm going to start going with wire fishing leaders attached to the motor mount. Core unit came down hard enough to bend the tube at the weak spot, right where the four rubber band holes are. I will reinforce this with a central "coupler" on the next build.
I'm finding the hardest thing about being a rocket engineer is the feeling, "Now I have to build another one to tweak this or that!"
One fin bent a bit, I think on landing. This is probably because I used 1/16" balsa even papered on one side. Would not have happened with 1/8" balsa with paper.
So lessons learned:
Use the right engine (B6-0)
Use heavier Balsa (1/8")
Use LESS PAINT (start with the right primer, probably simplify paint scheme)
Do a better job with the Tri-Fold mount (or better yet, use a wire leader on the motor mount)
BRING 4 MORE SPOTTERS! (Although flew this one solo, as it was experimental)
Video isn't great, but gives you an idea.
https://www.youtube.com/watch?v=svuXdVhQk2Q&feature=youtu.be
Hold your breath, I actually PAINTED something before I flew it (although I couldn't wait to make the decals, so flew it without them. The decals were going to be "Mayday! Mayday!", "Gone Fission", "Separation Anxiety", and the nuclear symbol. One on each of the four fins (but let's not get into the 3 fin 4 fin argument, my retention system for this design requires 4 fins.)
This model has motor retention, a central "core" holds the engine, has a streamer, a nose pyramid/forward fin retainer, and squares at front and back to guide/position the fins/sidewalls. Still uses rubber band/burn band retention for the back of the fins/sidewalls.
SHOULD have gone with B6-0, but didn't have any and Hobby Lobby not open on Sundays (my only local source of motors.) Wasn't sure an A8-3 was going to lift this. It has balsa fins/sidewalls, papered on the outside of the sidewalls and both sides of the fins. Had 5 coats of paint (grey primer, yellow--- then white primer when the yellow looks bad over the grey primer:bang:, yellow, yellow again, then orange trim. Thought the yellow and orange would contrast better, when they didn't, put down red mylar tape "pinstriping")---- anyway, 5 coats of paint, so figured would be too heavy. Probably would have worked.
B6-4 put it up to, I'm guessing here, about 250 feet. Did NOT pop the nose, came down ballistic (totally unintended) but the sidewall/fins apparently worked loose enought to break up at 150 feet. All pieces came down within 75 feet of the pad, but even with the short grass, still took me about 5 minutes to find all 5 piece.
No "holy burnt fins, Batman" on this one (the central core handles the engine gases nicely.) My trifold motor mount stuck out enough to hang up the streamer--- which may have been a GOOD thing as had this deployed at 250 feet I NEVER would have found all the parts. I'm going to start going with wire fishing leaders attached to the motor mount. Core unit came down hard enough to bend the tube at the weak spot, right where the four rubber band holes are. I will reinforce this with a central "coupler" on the next build.
I'm finding the hardest thing about being a rocket engineer is the feeling, "Now I have to build another one to tweak this or that!"
One fin bent a bit, I think on landing. This is probably because I used 1/16" balsa even papered on one side. Would not have happened with 1/8" balsa with paper.
So lessons learned:
Use the right engine (B6-0)
Use heavier Balsa (1/8")
Use LESS PAINT (start with the right primer, probably simplify paint scheme)
Do a better job with the Tri-Fold mount (or better yet, use a wire leader on the motor mount)
BRING 4 MORE SPOTTERS! (Although flew this one solo, as it was experimental)
Video isn't great, but gives you an idea.
https://www.youtube.com/watch?v=svuXdVhQk2Q&feature=youtu.be
