JimJarvis50
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I've mentioned this a few places already, but my Balls project this year will be a three stager. I would normally do a thread on a rocket after I fly it. But, the chances that this flight will actually occur and be 100% successful are pretty low. So if I do a thread in advance, at least I get to document the project. It's also likely that this group might spot some things I can do to improve the odds. The thread will just describe the rocket, the prep, the flight, and ??? (to be determined later).
This rocket isn't what you would end up with if you designed at three-stager from scratch. Instead, the rocket is a recycled-yet-again combination of my FourCarbYen and TooCarbYen rockets that I flew at LDRS and Balls last year. The after-the-fact flight reports on those flights were here:
https://www.rocketryforum.com/showthread.php?58733-Balls-2013-Personnal-launch-report-Jarvis
https://www.rocketryforum.com/showthread.php?56717-LDRS-32-Personal-Launch-Report-Jarvis
But, there have been lots of changes and problems to solve, and I never really did document the designs of either of those rockets. Three guesses on the name of the new rocket?
The first pic below shows a diagram of the rocket. Some of you may recall that I enlarged (crowned) the first stage fins to increase the stability. The upper and lower diagrams show how this affected the initial stability. I've seen a few three-stagers come off the rail and start sky-writing. I'd like to avoid that.
The motors for the flight will be the CTI N5800, the CTI N2501 and the Gorilla M745. Still Class II, but not by much. I hope that helps to get the flight approved (the first potential fatal flaw for the flight). I've been warned that I will need to have tiltometers (or the like) on both upper stages - which I have - and that the angle settings will be very restrictive (the second potential fatal flaw for the flight).
The second pic shows my simulations for the flight (via RasAero and Rocksim). The agreement is pretty good. Overall, the plan is to drop the first stage at motor burnout. After the second stage burn, however, the speed is too high to drop the second booster right away. So, the plan is to let the second and third stages coast together and then separate them at about Mach 1.2. Thus, these two stages would be coasting together through the jet stream. I think the odds of getting to the third stage ignition point without a tiltometer abort are pretty low. Not much I can do about that until I can implement active stabilization.
Anyway, that's the project. With the right weather and some luck, it could work, so help me out with some ideas, OK?
Jim
This rocket isn't what you would end up with if you designed at three-stager from scratch. Instead, the rocket is a recycled-yet-again combination of my FourCarbYen and TooCarbYen rockets that I flew at LDRS and Balls last year. The after-the-fact flight reports on those flights were here:
https://www.rocketryforum.com/showthread.php?58733-Balls-2013-Personnal-launch-report-Jarvis
https://www.rocketryforum.com/showthread.php?56717-LDRS-32-Personal-Launch-Report-Jarvis
But, there have been lots of changes and problems to solve, and I never really did document the designs of either of those rockets. Three guesses on the name of the new rocket?
The first pic below shows a diagram of the rocket. Some of you may recall that I enlarged (crowned) the first stage fins to increase the stability. The upper and lower diagrams show how this affected the initial stability. I've seen a few three-stagers come off the rail and start sky-writing. I'd like to avoid that.
The motors for the flight will be the CTI N5800, the CTI N2501 and the Gorilla M745. Still Class II, but not by much. I hope that helps to get the flight approved (the first potential fatal flaw for the flight). I've been warned that I will need to have tiltometers (or the like) on both upper stages - which I have - and that the angle settings will be very restrictive (the second potential fatal flaw for the flight).
The second pic shows my simulations for the flight (via RasAero and Rocksim). The agreement is pretty good. Overall, the plan is to drop the first stage at motor burnout. After the second stage burn, however, the speed is too high to drop the second booster right away. So, the plan is to let the second and third stages coast together and then separate them at about Mach 1.2. Thus, these two stages would be coasting together through the jet stream. I think the odds of getting to the third stage ignition point without a tiltometer abort are pretty low. Not much I can do about that until I can implement active stabilization.
Anyway, that's the project. With the right weather and some luck, it could work, so help me out with some ideas, OK?
Jim