There are disposable GOX tanks sold in hardware stores for small oxygen-propane torches... one might have enough gas to be useful for at least a few hybrid motor startups - how much GOX pressure does the Hypertek system want?
-dave w
And that would be the point.
There's a group working on a device which uses a burst diaphram. Can't wait to see the details.....
Joel. phx
How long is that motor? Seems to me the biggest problem of flying Mark's traffic barrel on a hybrid M would be accomodating the length of the motor.
One or two :-)
Actually, ALL of my HPR flying in the last couple of years has been with hybrids exclusively.
Also, it's 60 pounds without a motor. What's the weight of an M960Hybrid? I'm game if it hcan handle the job. I'm not married to solids. ;-) Besides, imagine the resonance chamber that the barrel's recessed base would make.
Mark Simpson NAR 71503 Level II God Bless our peacekeepers
For my burst diaphram I use 6 layers of vinly electrical tape. Secured by a tiewrap. My biggest issue with Pyrodex is it still makes a mess like BP because its basically the same thing. I was looking for cleaner.
This is the problem I had last Sunday. Flew my first RATT K240 with one of the new Accelo Rocket recording accelerometers. The first problem was seeing the darn thing vent. It was difficult to see. The second problem was the accelerometer didn't detect launch. I can now fit the 9 foot by four inch airframe into my glove compartment. I know I set it up correctly. Programmed it, double checked the axis setting, set the zero acceleration calibration, even tested the outputs the night before. Beats me what happened. But the RATT will fly again.
-- James L. Marino SAS, SARG, LUNAR, TCC, AEROPAC, NAR #75764 L2 TRA #9489 L2 AMA #761674
"Ban light pollution, not rocket motors."
"RayDunakin" wrote in message news: snipped-for-privacy@mb-m06.aol.com...
Was this too obvious? Got roasted last time I said that hybrids look like a pain in the rear, this time NADA.
There is also a lot of priceless information on
Thanks for the kind words. I'm glad Oscar was at LDRS to help out. Next year, LDRS should have a really nifty Hybrid Alley, with all the resources we've got: the Tri City Skybusters, Cesaroni and ProPoly within driving distance, PerfectFlite, X-Rockets, LOC, your humble correspondent and many more.
I went to a local welding supply store and rented the smallest GOX tank they have. It's lasted two years and is still going.
The HyperTEK instructions recommend 100 pounds of pressure on the regulator. Other experienced fliers have recommended 50 pounds. I split the difference at 75, and it seems to work great.
I'm looking into the disposable GOX bottles. It so happens that the Bernz-o-Matic factory is in Medina, New York, a mere eight miles from my home town.
Doug Pratt
And it is still true. People use reloadables because of a falsified availability structure by AeroTech. Shipping, permits, etc.
Those ROCKETEERS who are FLYING ROCKETS and have a 50/50 choice between reloadables and expendables generally choose expendables.
Jerry
Hi Doug,
The required GOX pressure regulator setting of 80~100 PSI is outlined on page 5 of the HyperTek manual and referenced on page 8. This setting was arrived at after hundreds of test firings and many flights. A lower pressure than this may cause intense localized burning at the top end of the fuel grain. Pyrolysis of the remaining fuel grain will occur in the oxygen depleted environment and may cool the gas flow sufficiently to delay the tie wrap release or cause a warm start. In the mean time, the fill stem will continue to superheat at the top and may melt or burst.
An analogy is correct placement and selection of the igniter in a solid motor.
Regards, Anthony J. Cesaroni President/CEO Cesaroni Technology/Cesaroni Aerospace
Hmmm, I've not had annual visits. Just several at the beginning, and the
9/11 followup. I've NEVER wasted my vacation time to deal with this. I make THEM fit MY schedule. After all, the hours on my application do NOT say 8-5 M-F!Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!
Relaodables are cheaper if you fly enough and never lose your rocket or casing. I prefer SU, but the particular SU motor needed may not be availsable.
I certainly would, but then all things are not an equal 50/50.
Hybrids look attractive for some cirumstances, and have more scope for experimentation, so some people just bear the pain.
Alan
You keep your collection of 1/4A motors in a magazine?
Hey, quit picking on him. He has a -full- A motor too. He keeps it in a safe place on the top shelf, "out of the reach of children" because the label says so.
steve
From the Accelo web page:
Liftoff Detection: When acceleration is greater than 2 g for more than
0.25 seconds.They don't show both sides of the circuit card but from looking at the front I do not see anything even vaguely resembling a low pass filter for the accelerometer. I strongly suspect that they just ran the output directly to the microcontroller.
Combine this with the K240 and you have a recipe for non-deployment. Do not mess with Mr. Nyquist or he will bite you in the gas. :-)
This is a well known problem (to some anyway) with accelerometer based systems and some hybrid motors.
James L. Marino wrote: > This is the problem I had last Sunday. Flew my first RATT K240 with > one of the new Accelo Rocket recording accelerometers. The first problem was > seeing the darn thing vent. It was difficult to see. The second problem was > the accelerometer didn't detect launch. I can now fit the 9 foot by four > inch airframe into my glove compartment. I know I set it up correctly. > Programmed it, double checked the axis setting, set the zero acceleration > calibration, even tested the outputs the night before. Beats me what > happened. But the RATT will fly again. >
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