ActingLikeAKid
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I've decided to call this the Tattooine Express.
I have a Solar Warrior and bought a second kit to scavenge the motor mount when the mmt blew out of the first one. And then I bought a third kit because...I'm not sure. But I had this great idea: What if I doubled-up the body tube and stuck a 29mm motor in there?
Answer: It's awesome. And I decided on the name because I'm a giant nerd and Tattooine has two suns, so double Solar Warrior - two suns....
I saved up all my pictures to do this in one fell swoop.
FINS:
The Solar Warrior kit comes with super cool fins with little finlet wingtips. I skipped these because I figured they might rip off at the speeds/G forces I'm hoping to achieve.
There's a little tenon sticking out from the end of the fin that fits into a hole in the finlet. I just sanded that off with some 100 grit. Then I glued together the fins, bondo'd the seam, and papered them. BIG PROPS to the Elmer's Glue-All purple glue stick, it makes papering super easy.
I also got a coupler baffle from Apogee. As I said, I started this with the plan to just use two regular-length BT-60 tubes. If I had it to do all over again, I think I'd shorten them each a bit just to make a sturdier airframe. Anyway, I put the baffle together with some possibly-unnecessary aluminum foil on the bottom and a Kevlar cord loop on the top (using K'Tesh's double-loop cord method to secure the shock cord.) Lots of epoxy in there.
Got the tubes filled and sanded and marked for fins. Glued on the fins with epoxy. Installed the coupler. Started thinking hard about how/when to install the rail buttons, launch lug (yes, I did both) and motor mount. Decided to write everything down:
...and it all worked exactly as planned. Bonus tip: If you need to install a t-nut on the inside of a body tube, wrap a piece of masking tape around a knife (or a ruler, I guess, if it's way in there) sticky-side out. Secure the tape with another piece of tape.
This works really well.
I put 15g of weight in the nose cone, in the form of an egg-style fishing sinker and a big gob of epoxy. Used a bamboo skewer to hold the weight in place while the epoxy cured. Got some 3/8" elastic and made a shock cord the length of the rocket - about 42". Used the stock parachute; I figured that I spill-hole'd the stock one, but this would be a lot heavier than stock.
I was trying to hustle through this build, so I don't have a ton of pictures of it, but it came out pretty well. I managed to get it primered in time for the launch this weekend. Here it is, post-launch:
I really, really like how this rocket came out.
FLIGHT:
The E16 I put in it put in it simmed to about 900 feet, but it looked like it went a lot higher than that. I blew my rocket budget for the month on a Chute Release, so maybe an altimeter next month? It roared off the pad with a nice throaty black-powder burn, popped at apogee and ..... took.... forever to come down. I really regretted not either putting a spillhole in the chute or using the Chute release or both. There was a brisk surface wind, so when it got down to about 100 feet, it really started moving away. Landed a good 1/4 mile from launch, and the wind was blowing hard enough to lift the whole rocket and move it around.
There was a little damage to the lower BT, I think it was either the rocket getting knocked around in the wind ... or just the might of the 29mm motor pushing against a long thin BT. I posted these on the NAR fb page, and got recommendations from "eh, it's fine" to "fiberglass it!".... I actually considered the latter, but that seems like a huge step up. Glassing is a skill I'd love to get, but it seems messy, time consuming, and dangerous for this application. I think I'm going to go with my original plan - gluing on some strakes that go from the bottom mmt to the coupler, reinforcing the bottom BT. I think thin strips of basswood would be ideal ... and probably look pretty cool if I do it right.
I have some F motors ready to go once I've got the strength issue addressed!
I have a Solar Warrior and bought a second kit to scavenge the motor mount when the mmt blew out of the first one. And then I bought a third kit because...I'm not sure. But I had this great idea: What if I doubled-up the body tube and stuck a 29mm motor in there?
Answer: It's awesome. And I decided on the name because I'm a giant nerd and Tattooine has two suns, so double Solar Warrior - two suns....
I saved up all my pictures to do this in one fell swoop.
FINS:
The Solar Warrior kit comes with super cool fins with little finlet wingtips. I skipped these because I figured they might rip off at the speeds/G forces I'm hoping to achieve.
There's a little tenon sticking out from the end of the fin that fits into a hole in the finlet. I just sanded that off with some 100 grit. Then I glued together the fins, bondo'd the seam, and papered them. BIG PROPS to the Elmer's Glue-All purple glue stick, it makes papering super easy.
I also got a coupler baffle from Apogee. As I said, I started this with the plan to just use two regular-length BT-60 tubes. If I had it to do all over again, I think I'd shorten them each a bit just to make a sturdier airframe. Anyway, I put the baffle together with some possibly-unnecessary aluminum foil on the bottom and a Kevlar cord loop on the top (using K'Tesh's double-loop cord method to secure the shock cord.) Lots of epoxy in there.
Got the tubes filled and sanded and marked for fins. Glued on the fins with epoxy. Installed the coupler. Started thinking hard about how/when to install the rail buttons, launch lug (yes, I did both) and motor mount. Decided to write everything down:
...and it all worked exactly as planned. Bonus tip: If you need to install a t-nut on the inside of a body tube, wrap a piece of masking tape around a knife (or a ruler, I guess, if it's way in there) sticky-side out. Secure the tape with another piece of tape.
This works really well.
I put 15g of weight in the nose cone, in the form of an egg-style fishing sinker and a big gob of epoxy. Used a bamboo skewer to hold the weight in place while the epoxy cured. Got some 3/8" elastic and made a shock cord the length of the rocket - about 42". Used the stock parachute; I figured that I spill-hole'd the stock one, but this would be a lot heavier than stock.
I was trying to hustle through this build, so I don't have a ton of pictures of it, but it came out pretty well. I managed to get it primered in time for the launch this weekend. Here it is, post-launch:
I really, really like how this rocket came out.
FLIGHT:
The E16 I put in it put in it simmed to about 900 feet, but it looked like it went a lot higher than that. I blew my rocket budget for the month on a Chute Release, so maybe an altimeter next month? It roared off the pad with a nice throaty black-powder burn, popped at apogee and ..... took.... forever to come down. I really regretted not either putting a spillhole in the chute or using the Chute release or both. There was a brisk surface wind, so when it got down to about 100 feet, it really started moving away. Landed a good 1/4 mile from launch, and the wind was blowing hard enough to lift the whole rocket and move it around.
There was a little damage to the lower BT, I think it was either the rocket getting knocked around in the wind ... or just the might of the 29mm motor pushing against a long thin BT. I posted these on the NAR fb page, and got recommendations from "eh, it's fine" to "fiberglass it!".... I actually considered the latter, but that seems like a huge step up. Glassing is a skill I'd love to get, but it seems messy, time consuming, and dangerous for this application. I think I'm going to go with my original plan - gluing on some strakes that go from the bottom mmt to the coupler, reinforcing the bottom BT. I think thin strips of basswood would be ideal ... and probably look pretty cool if I do it right.
I have some F motors ready to go once I've got the strength issue addressed!
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