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edward.
edward.-
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Adrian
Here’s a 24mm rocket I’m working on getting ready for MHM:
Look ma, no strings! (or helium)
It’s mostly designed around an Ellis G37, but I’m keeping the back end light so that I can also fly it with a lighter nosecone and an E6, assuming I can get it back after the G37. It will be carrying a Parrot and a beeline.
Anonymous
Adrian, by your caption, I assume that you are holding at the C/G (and not just sticking your hand in there for reference?) The G37 sounds like a great load. Is it still being made since Bob Ellis passed away?
If that is your CG, how much lead do you have up there? Yikes!
What do you sim to? It would appear my 15 minutes of fame as the TRA record holder may be drawing near an end 8) I wish you good luck, you’ve worked very tirelessly on these smaller rockets!
I’m going to try to increment the I record, as well as the M record at MHM…
JW
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Adrian
Yes, I’m holding it at the CG, with the rocket unloaded below the nosecone. It’s so odd handling it when it’s that nose-heavy I thought I would try to capture the sensation in a photo to share. The nosecone is full of 120 grams of lead shot and epoxy (still composite construction 🙄 )
The G37 is no longer being made. If this rocket sets a record I’ll name it the Ellis Mountaineer in tribute to Robert Ellis’s fine work. A few months ago I bought 5 G37s, and sold one to Mike Konshak at the annual meeting. I’d also like to try to set the G-impulse 2-stage record over 13k with a G37-E6 combination. If things go well, that should leave one or two that I would be happy to give to you. Given my success rate, though, no promises. The cert runs out at the end of the year.
The rocket sims north of 9k. I’d like for the first TRA record I break be one other than yours, but the F10 based rockets have been kicking my butt so I wanted to take a break from that.
slipstick
keep in mind venting the motor because some motors do not light well if there is no air and the extra drag up to the point the second motor lights and separates from booster… … The most important thing is to keep the ignition source on the sustainer and not the booster, it helps to insure the motor has a chance to light.
James.
The original plan is to use the Booster timer to separate at 4.5 sec. The K700 burns for 3.59 sec. The Sustainer will be set to ingnite 1 sec later at 5.5 sec. A little coast will happen during the delay.
I’m still debating about using the sustainer timer to do the separation. It makes my construction a little more complicated. but it allows a more accurate synchronization of the separation charge and the sustainer igniter because they would trigger off the same 2.5 G signal.
If I can fit one in, I will use an altimeter rather than the other channel of the Pet2 timer to detect booster apogee for chute deployment.
What’s the best way to keep the igniter in the sustainer motors as the rocket separates?
I forgot to give you the e-matches for the igniter. will you be able to make up a couple for me at MHM? Thanks.
James Russell
What’s the best way to keep the igniter in the sustainer motors as the rocket separates?
with the K700 it comes with a red cap, use a dowell like on your L3 and use the cap to hold it in place but be sure to cut a hole in the cap so that it does not have a problem lighting.
I forgot to give you the e-matches for the igniter. will you be able to make up a couple for me at MHM?
No problem.
Anonymous
I’d like for the first TRA record I break be one other than yours, but the F10 based rockets have been kicking my butt so I wanted to take a break from that.
Thanks! (I think 😉 ) I have something of a history of short-lived TRA records. I once held the M Hybrid record, but it only lasted about 15 minutes. The guy who flew immediately after me beat me.
My TRA “L” record got crushed, and I had moral victories on for a J and and H boost — beating existing TRA records, but not by the prerequisite 2%. Suffice to say, it gets very competitive at that level.
I just finished an I rocket yesterday that I have high hopes for – pun intended 8)
Anonymous
Adrian, I sent you a PM
slipstick
The original plan is to use the Booster timer to separate at 4.5 sec. The K700 burns for 3.59 sec. The Sustainer will be set to ignite 1 sec later at 5.5 sec. A little coast will happen during the delay.
Actually, I double checked my numbers (it 2AM when I wrote the above) in order to get to 3 miles I need to let the sustainer coast for 6 sec after separation, (i.e 10 sec into the flight) I know if the rocket tilts over during boost the delay could cause more distance down range than desired, but I kind of hate to spend the money on the motors and not reach another self-imposed goal, although it is riskier Here’s the basics of the flight
T+0 Launch booster (AGL)
T+3.6 Booster Burnout/Separation/Sustainer coasts (2000 feet)
T+7.6 Deploy Booster Chute (allowed 4 sec of coast)
T+9.6 Ignite Sustainer (5400 ft)
T+13.2 Sustainer Burnout/Coasts (9500 ft)
T+30 Theoretical Apogee (15700 ft)James Russell
As long as you have a good speed still 10 sec. in to the flight you will be OK but that is a long cost time.
SCOTT EVANS
The original plan is to use the Booster timer to separate at 4.5 sec. The K700 burns for 3.59 sec. The Sustainer will be set to ignite 1 sec later at 5.5 sec. A little coast will happen during the delay.
Actually, I double checked my numbers (it 2AM when I wrote the above) in order to get to 3 miles I need to let the sustainer coast for 6 sec after separation, (i.e 10 sec into the flight) I know if the rocket tilts over during boost the delay could cause more distance down range than desired, but I kind of hate to spend the money on the motors and not reach another self-imposed goal, although it is riskier Here’s the basics of the flight
T+0 Launch booster (AGL)
T+3.6 Booster Burnout/Separation/Sustainer coasts (2000 feet)
T+7.6 Deploy Booster Chute (allowed 4 sec of coast)
T+9.6 Ignite Sustainer (5400 ft)
T+13.2 Sustainer Burnout/Coasts (9500 ft)
T+30 Theoretical Apogee (15700 ft)You know Miike.
I noticed on the multi-stage sims Ive done, you can get higher altitudes with more coast time between the booster and the sustainer. But like you said What if the rocket isnt 100% verticle! 😯
Adrian
Anonymous
slipstick
James Russell
SCOTT EVANS
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