What are you using for tracking & how are you going to initiate recovery?
24mm MD 10,000 ft and Mach 1.6 on a CTI G150
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What are you using for tracking & how are you going to initiate recovery?
I think I'll try this for tracking (https://www.apogeerockets.com/Elect...Beacon?zenid=5b3676585701e57803fd3e960360b40e) and this for recovery (https://www.apogeerockets.com/Elect..._Timer?zenid=5b3676585701e57803fd3e960360b40e)
bobkrech
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Steve Boetto's TRA F-altitude record was actually in a 29 mm single stage rocket using an Apogee F10 which brought it to 5407' AGL at sea level which is really impressive.
https://www.rocketryforum.com/showthread.php?130760-New-F-record-at-Bunnell-Florida
The NAR G-impulse record for a single stage G-impulse appears to be 6795' AGL in a 29 mm rocket using an AT G80-13T and recorded on a 12 gram PerfectFlite Pnut Logging Altimeter. (NAR requires a logging altimeter for altitude records). The unlimited G-altitude record appears to be 8665' AGL but I don't know if it was a single stage or multi-stage rocket but it was not recorded with an altimeter. A 24 mm 160 Ns G80 theoretically could reach 11.5 kft scaling from the NAR G-impulse record. A G150 will have more speed and more drag so it is not likely to go that high all else being equal so the flight should be interesting.
Added. If you want to make it cheap, how about starting out with a discontinued LOC Precision Mini Kit. The LOC website indicates some are left for $10 each. https://shop.locprecision.com/category.sc?categoryId=30 is a 24 mm LOC Hi-Tech mini complete with streamer. Ditch the 18 mm motor mount and use the Pro24. Ditch the balsa fins and use real A/C grade Baltic birch fins although 1/16' CF fins of this size would be cheap. Rocket would be ~$20 plus have plenty of room in the NC for a $50 Pnut ltimeter as well.
Bob
Bob,
The unlimited G altitude record was set using a G150 in a single stage 24 mm MD rocket. (https://www.rocketryforum.com/showt...G-motor-altitude-record-(unoffical-as-of-now)) That's why I planned to use the G150. The 29 mm G motors have too much drag, the other 24 mm G motors don't have enough performance and the G65 (which is the only motor in the Pro 24s to have more impulse than the G150) has an offset core, which will probably make the rocket corkscrew and lose the advantage of any extra altitude that it might get.
RocketFeller
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That is an interesting point - do moonburners really have asymmetrical thrust?
No, the offset core displaces mass on one side. With large, heavy rockets moonburners are fine, but with light, MD rockets they tend to corkscrew.
RocketFeller
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Thanks, that makes sense.
bobkrech
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If you reread my post you will see I referenced the NAR records, not TRA, which was accomplished on a 29 mm G80. (I had forgotten the post your referenced which I had also posted in.) Please note that I had scaled the NAR result to a 24 mm 160 Ns G80 motor to obtain a potential altitude record of 11.7 kft for a 100%G 24 mm MD rocket. I also made the comment that I don't think you will get that apogee with a 150 N thrust motor because of the excess speed and drag.
Today I ran a few quick sims for an optimized 24 mm MD rocket in RASAero 2 and don't even break Mach with the G150 which is what I expected, and matched the current TRA G record apogee in the process. I also got a substantially higher apogee with the G65 which also breaks Mach by a small amount which again is in agreement with my previous comments.
Time for you to build, launch and see what you get.
Good luck.
Bob
Is there a pic of the NAR G altitude rocket?
bobkrech
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No pix for NAR.
The Q&D Sim I ran looked like the TRA rocket, and reached a similar apogee as the TRA record on the G150 with the same base altitude as the record flight.
Bob
On the recovery, why not use a PerfectFlight StratoLogger CF. 11g, logging altimeter, and can control your deployment at apogee. Also reusable in future projects.
When are you going to build it?
rockets
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Yeah, it looks great!
No matter which one you build, you're going to have to tweak it after each flight assuming you even recover it. Steve Boetto probably went though 5 different designs and lost 2 even with gps.
Thanks. I think that I might switch to CF or Fiberglass for this rocket, since the price of it is getting pretty high (around 120$ for the electronics alone :y
Hey TRFfan, how's your build going? Any updates? Looking forward to seeing some pics!
Yeah, I'm getting some parts made by Lister on the australian rocketry forum. The design of the rocket has also seen a lot of changes, and I think I'm close to the final revision.
Why don't you just build one & see what happens? Remember, it is rocket science.
You can reduce powder to make it not a special consideration that it's a G motor. However, the rocket does need to be bigger (longer) due to the motor, recovery will take at at least as much space as a similar sized rocket with an A motor, and you don't have it. Plus more if an altimeter, etc.. I also think the rocket will have poor damping coefficient because it's very heavy for the size of the aerofoils.
bobkrech
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Your OR file has several errors or needed changes.
The fin rotation should be 0 degrees, it is unrealistic that the surface finish is polished (2 um) but more likely 20 um, parachute diameter should be 9" (Lightweight International Orange), fins are air-foiled?????, fins are too small regardless of what OR calculates (should have 1" span, 2" cord), filet radius should be 0.125" not 1 cm, ballast can be 0.5 oz. or you cab simply lengthen the airframe, I don't see your electronic deployment as maximum motor delay is 3 seconds too short. (without electronic deployment, max delay reduces apogee by 144' with a deployment speed of 65 mph).
I get an apogee of ~8,900 agl with max v = 1,350 mph or Mach 1.82. Increasing the mass, but not in the nose, probably would reduce the velocity and increase the apogee.
Bob
2 micron is not unreasonable.
20 micron is 400grit particle size.
2000 grit wet&dry is ~1micron
Mylar on fibreglass would easily meet 2micron.
Check a surface roughness gauge/comparator and I think you'd be surprised how rough 20u is.
20 micron is 400grit particle size.
2000 grit wet&dry is ~1micron
Mylar on fibreglass would easily meet 2micron.
Check a surface roughness gauge/comparator and I think you'd be surprised how rough 20u is.
Ok, here's a new file. I changed some stuff around in it and it looks much better now.
View attachment 285926
View attachment 285926
As Mr. Krech has stated, it is time to build and let us know how it performs
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Very impressive design
danielsadjadi
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That is false. 400 grit is closer to 30 microns distance, 10,000 grit on a rocket will likely give you 2-3 microns particle per grit size. See attached for info.
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