Aslansmonkey
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- May 3, 2021
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A while back I got it into my head to design a model rocket based on the MK82 Snake Eye bombs of the Vietnam era. In my research on the topic I came upon the "Mk82 High Drag Bomb Rocket" thread on this forum (https://www.rocketryforum.com/threads/mk82-high-drag-bomb-rocket.64002/) and the work Chris Attebery did on the idea. While he worked with wood, I had a 3D printer available so I used that instead, basing my designs on what I could see on photos of the actual bomb.
The first one was an 18mm motored version...which failed. The second one was also an 18mm version, which almost worked, but still failed. But that one was close enough that my third design for 18mm motors worked. That design is here: https://www.thingiverse.com/thing:4847720
For my next design, I wanted to go bigger, so I designed a version that looked very much like the original bomb using a lot of 3D printed parts including the petals (the entire petal was 3D printed with a built in taper) and designed it around 18mm motors. It failed...twice. There was never a good chance of success with this one because it came out really heavy, but I had to try. The first flight went up ok, but came down too fast and damaged the inner tube of the rocket. I rebuilt it and tried again and the second flight was...well...almost, but not quite, completely unstable. That rocket survives, but is good only for a display.
The third design, also 18mm, was submitted to Apogee rockets. I tried to minimize the 3D parts this time and used mostly purchasable parts with an eye to reducing weight and increasing the float performance. You can read all about that one here: https://www.apogeerockets.com/Peak-of-Flight/Newsletter551
I make a lot of rockets based on Pringles cans, so it was only natural I make a version for those as well. The first design was meant to simplify the construction, particularly the fins and though it worked, it came down to fast. I added webbing between the petals which helped, but I was unhappy with the design. So I made another version which can be found here: https://www.thingiverse.com/thing:4982215
But then I thought...18mm...24mm...I need to try a 13mm to "complete the set" of the smaller black powder motors, and this thread will show that build.
I will point out, that at the time of posting this thread I have completed two versions of the rocket and flown them each twice successfully, so what you will be reading here is not a thread of an experiment but rather the build instructions for a working design.
The design for the 13mm rocket can be found here: https://www.thingiverse.com/thing:5028681
The first one was an 18mm motored version...which failed. The second one was also an 18mm version, which almost worked, but still failed. But that one was close enough that my third design for 18mm motors worked. That design is here: https://www.thingiverse.com/thing:4847720
For my next design, I wanted to go bigger, so I designed a version that looked very much like the original bomb using a lot of 3D printed parts including the petals (the entire petal was 3D printed with a built in taper) and designed it around 18mm motors. It failed...twice. There was never a good chance of success with this one because it came out really heavy, but I had to try. The first flight went up ok, but came down too fast and damaged the inner tube of the rocket. I rebuilt it and tried again and the second flight was...well...almost, but not quite, completely unstable. That rocket survives, but is good only for a display.
The third design, also 18mm, was submitted to Apogee rockets. I tried to minimize the 3D parts this time and used mostly purchasable parts with an eye to reducing weight and increasing the float performance. You can read all about that one here: https://www.apogeerockets.com/Peak-of-Flight/Newsletter551
I make a lot of rockets based on Pringles cans, so it was only natural I make a version for those as well. The first design was meant to simplify the construction, particularly the fins and though it worked, it came down to fast. I added webbing between the petals which helped, but I was unhappy with the design. So I made another version which can be found here: https://www.thingiverse.com/thing:4982215
But then I thought...18mm...24mm...I need to try a 13mm to "complete the set" of the smaller black powder motors, and this thread will show that build.
I will point out, that at the time of posting this thread I have completed two versions of the rocket and flown them each twice successfully, so what you will be reading here is not a thread of an experiment but rather the build instructions for a working design.
The design for the 13mm rocket can be found here: https://www.thingiverse.com/thing:5028681
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