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- Nov 8, 2015
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In 2004 I designed a rocket to carry my son's 12" GI Joe and launch him out on his own parachute. I did it only because he asked if it could be done and it got me thinking. At that point I'd just finished the Apogee Saturn V after a 25 year break in building any rockets. I figured it'd be a lot of fun to do; but gotta admit. I suck at math and it took a long time to design using excel spreadsheets and calculations. At the time I didn't have this site, and had a older version of rocksim i'd purchased when I got the Saturn V. Thankfully it was a success and we got to launch it one time. Then we never found a place large enough to launch again until this past spring in 2016 at battle park.
It had two more launches at NOVAAR until some NUMB NUT (looking in the mirror) forgot to Turn ON the ChuteProtector. It did it's job and protected the chute all the way to the ground! :bang: I had made the fins out of balsa, thus it didn't work out at all. Chalk that up to stupid mistakes and engineering! Anyway, I found my old 2004 visio diagram and rkt file, did a little touch up and have decided to start again.
Original design
I reached out to Mike at Binder Designs (thanks to some good recommendations) and he cut nice 1/8" plywood fins for me (no balsa this time!), as well as some 1/8" centering rings, a new body tube, and a new MMT tube. With that, I've set out to rebuild this fun rocket.
Since I ordered the tube bare, I had to go back to cutting my own fin slots. I started off with Payloadbay.com but realized the wrap only showed a single line for the fin alignment; whereas I wanted an exact 1/8" line so I could mark each side. I found my old visio drawings and modified them slightly to ensure it was the right circumference and the slots were perfectly spaced. Measuring the printout, I taped the guide to the body and marked both the bottom and top fin areas. I figured using angle iron was the best approach to ensuring I kept a straight line and also to cut a straight line having an edge to control the blade. I was pleased with the outcome.
I test fit the fin in each slot, with a little light sanding on one slot, and eventually got all the fins inserted.
I seem to have a slight curve in the top of the fins because when I put the angle iron beside each fin, I'm off the line following up the body tube. Laid them on a flat surface, and sure enough, slightly off. I'll either tack in place when I get to that point with ca to hold in alignment, or see about re-compressing them for a while. I'm sure it'll work out as they aren't warped horridly, just slightly. Anyway, on to the mmt. It was a full length tube, so I cut it to 12.5" and then measured the appropriate distance in Rocksim for the CRs and taped them in place to see what a test fit looked like. That didn't work out so well as the tape just released, so I carefully aligned the top CR, glued in place and then just tacked on the middle (upper tab surface point) and test fit. Good to go. Finally with that in place I've secured both CRs in place and will leave off the rear until done I can take care of mounting the fin tabs with fillets.
I need to pick up another aeropack 29mm retainer and an eyebolt for the top CR; but have been able to pull all other parts from the existing rocket. Thankfully the nosecone is fine as well, and fits. Also I designed this one with an internal baffle to push GI Joe out without allowing the hot gasses to come into contact. That fits this new tube perfectly. I also have to start thinking about a new paint job. I cannot find the paint I used before; which looked really cool in the sun, and am seriously considering doing some sort of Stickershock design; but I have to come up with it first. One thing is for certain, I need to put an extra tie wrap around GI Joe's waist so if I wish to attach a camera again, I'll get it back! The #2 stupid thing I did on the same day it crashed, was to attach the camera to his belt on a preceding flight. No idea WHAT I was thinking, but anyone walking about the fields at Great Plains, Va, might run across an 808 with some very interesting footage on it.
It had two more launches at NOVAAR until some NUMB NUT (looking in the mirror) forgot to Turn ON the ChuteProtector. It did it's job and protected the chute all the way to the ground! :bang: I had made the fins out of balsa, thus it didn't work out at all. Chalk that up to stupid mistakes and engineering! Anyway, I found my old 2004 visio diagram and rkt file, did a little touch up and have decided to start again.
Original design
I reached out to Mike at Binder Designs (thanks to some good recommendations) and he cut nice 1/8" plywood fins for me (no balsa this time!), as well as some 1/8" centering rings, a new body tube, and a new MMT tube. With that, I've set out to rebuild this fun rocket.
Since I ordered the tube bare, I had to go back to cutting my own fin slots. I started off with Payloadbay.com but realized the wrap only showed a single line for the fin alignment; whereas I wanted an exact 1/8" line so I could mark each side. I found my old visio drawings and modified them slightly to ensure it was the right circumference and the slots were perfectly spaced. Measuring the printout, I taped the guide to the body and marked both the bottom and top fin areas. I figured using angle iron was the best approach to ensuring I kept a straight line and also to cut a straight line having an edge to control the blade. I was pleased with the outcome.
I test fit the fin in each slot, with a little light sanding on one slot, and eventually got all the fins inserted.
I seem to have a slight curve in the top of the fins because when I put the angle iron beside each fin, I'm off the line following up the body tube. Laid them on a flat surface, and sure enough, slightly off. I'll either tack in place when I get to that point with ca to hold in alignment, or see about re-compressing them for a while. I'm sure it'll work out as they aren't warped horridly, just slightly. Anyway, on to the mmt. It was a full length tube, so I cut it to 12.5" and then measured the appropriate distance in Rocksim for the CRs and taped them in place to see what a test fit looked like. That didn't work out so well as the tape just released, so I carefully aligned the top CR, glued in place and then just tacked on the middle (upper tab surface point) and test fit. Good to go. Finally with that in place I've secured both CRs in place and will leave off the rear until done I can take care of mounting the fin tabs with fillets.
I need to pick up another aeropack 29mm retainer and an eyebolt for the top CR; but have been able to pull all other parts from the existing rocket. Thankfully the nosecone is fine as well, and fits. Also I designed this one with an internal baffle to push GI Joe out without allowing the hot gasses to come into contact. That fits this new tube perfectly. I also have to start thinking about a new paint job. I cannot find the paint I used before; which looked really cool in the sun, and am seriously considering doing some sort of Stickershock design; but I have to come up with it first. One thing is for certain, I need to put an extra tie wrap around GI Joe's waist so if I wish to attach a camera again, I'll get it back! The #2 stupid thing I did on the same day it crashed, was to attach the camera to his belt on a preceding flight. No idea WHAT I was thinking, but anyone walking about the fields at Great Plains, Va, might run across an 808 with some very interesting footage on it.
Has worked flawlessly.
