At my first club launch in April, I flew a newly-finished, scratch-built rocket: The Ceres B booster with the "ICU2" camera payload bay.
The original design is from Mike Westerfield's book, Make: Rockets: Down-to-Earth Rocket Science. It's a largish, BT-60-based rocket (about 1.637 inches in diameter), with four trapezoidal fins and a fatter, BT-80 (2.6 inches) payload section. The payload houses a hidden camera, with plenty of room left for an altimeter - and even an egg or two if you want to launch that.
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| The camera view port |
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| The hidden USB spy cam tucked inside. The camera only cost about $5. |
You can tape a miniature camera to the side of most rockets and get some fun video. What I like about this rocket is that the camera is part of the design; it's hidden from view and isn't just stuck on the side.
The rocket, as designed, is a basic model rocket with a 24mm diameter motor tube, and can fly on either D or E black powder motors.
I had quickly built a 3-finned version some time ago, and lost it on its first flight with an Estes E9-6 motor. I lost the payload earlier than that, on an ill-advised flight of another rocket I'd designed. The payload was on its own, far too large parachute, and the wind carried it away.
I decided to soup up the design a little, replacing the traditional motor hook with an Estes Quick Release screw-on motor retainer, and leaving out the engine block or thrust ring. With a nice, long motor tube and no hook to get in the way, the rocket is now very versatile, and can fly on anything from a D12 black powder motor up to F and even a few G composite motors, giving it an altitude range of 440-3100 feet.
The fins were built up from three pieces of material, making them nice and strong, and have a fin root tab for through-the-wall construction, firmly attaching them to the rocket.
The fins also have beveled leading and trailing edges, and are radially-tapered, meaning they get thinner toward the tip as they radiate out from the body of the rocket. At the roots, the fins are about 1/8 inch thick, and about 1/16 inch thick at the tips. This not only makes them more aerodynamically efficient, it also looks really cool on the finished rocket.
Apart from a couple problems with the finished paint job, I'm really pleased with the way this rocket turned out, and plan to try flying it on many different motors.
My order of AeroTech composite motors did not arrive in time for my first launch, so I had to use an Estes E9-6 for the first flight. I still got a really good video of it, and the rocket came back with no damage.
Jolly Logic has even put the video on their website, because I used both the Altimeter Two and the new Chute Release in this video.
I'll show some of the things I did to build this rocket the way it is in a future post. If you're interested in building the design, check out Mike Westerfield's book - even built as a basic model rocket, it's a good one.
For now, here's the video:
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Daniel - did you build-up a thrust ring with tape on the E9-6 or did you do something different? I'm leery of leaving out engine blocks though I know it's common practice.
ReplyDeleteYou can do tape, but in this instance, I used a tip from a fellow CMASS member. I cut a very short bit of BT-50 body tube - about 1/4 inch long, max - and glued it to the very bottom of the motor with wood glue, just where you'd use tape. I actually did two layers of body tube, just for the added security.
DeleteThe wood glue left is very strong, and shouldn't fail, and it meant that I didn't have to cut off extra tape, as all my masking tape is too wide to make a thrust ring without trimming it down.
If I do it again, I'll take a picture.
Did you make the transition or did you purchase it as a custom piece? I would really like to do something like this for my Estes Ventris.
ReplyDeleteIt's a balsa transition, purchased from JonRocket.com. It's a BT60/BT80 transition.
DeleteI've thought of doing something similar with the Ventris, but there's not as much space between the outer diameter of the main body tube and that of the payload section. But the top shoulder of the transition in the Ventris is slanted. It has an eye for attaching something to it (the shock cord in the Argent, actually, which uses the same transition as the Ventris, but upside down).
If you cut off the eye on the part of the transition shoulder that sticks up into the payload section, you have a flat, slanted surface. There will be a hole there once you've cut it off, but you can fill it with putty or cover it with duct tape. If you drill a hole into the side of the payload section at just the right place, you can simply tape a spy cam onto the slanted part of the shoulder to see out the hole. You wouldn't get a view straight down the body of the rocket, but you would get a downward-slanted view.
Or, you could simply tape a camera on top of the transition shoulder, and have a hole right next to it, and have a horizontal view out of the payload section.
Actually, now that I think of it, some of those 808 cameras might be able to be disassembled. The lens is connected by a wire to the electronics. You could take the guts out of the 808 camera and without the body, the camera would be a lot smaller. You could probably rig up some kind of tunnel to see straight down through the transition. I think it's about a 1/4 inch difference between the outer diameter of the main body tube and the payload section.