I am suggesting ADDING small solids as a backup.
At least until the fakeout and ignition issues are resolved for the
hybrids. It is possible hybrid flight reliability will always justify a
simple pyro delay backup.
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: firstname.lastname@example.org>
Huh? Launch detect on an underpowered Hybrid is no different than on
an underpowered solid.
The oscillation issue on some hybrids should not be a concern if you
choose your altimeter appropriately.
The High Voltage issue used with some hybrids does require careful
physical design to keep sensitive electronics away from the HV.
My experience with hybrids reliability is that once they are lit they
are just as reliable as AP motors. Partial fills is the biggest
problem I've seen, and that usually tapers off with experience.
Failing to detect apogee by both would have been saved by a manual button
push. Or was it out of sight at that point? Having a large backup charge
would have saved in the event of too small a charge.
Brian, can you tell us more? Did you determine the cause of the failure?
Were you able to determine if the charges fired?
Were the altimeters accelerometers or baro?
Were the altimeters the same brand and model or different?
Had this combination flown successfully prior to this flight?
I have twice had the problem of the apogee charge firing but the rocket
not separating. I solved that problem by using a sufficiently sized
charge to ensure separation no matter what deformation might occur
during flight that could cause the sections to not separate, and
designing the system to survive that charge size.
No, not really.
We had to switch Hypertech M motors at the last minute due to a missing O
ring. The tank on the second motor didn't fit very well. We had to
hammer the motor in which probably didn't help things at all.
I don't recall for sure. Everything was pretty well crunched. I dimly
recall that the charges didn't fire.
Missileworks RRC2 and an Adept deployment controller.
Yes, they both flew with a Hypertech M in a different rocket the year
I had this rocket not seperate at apogee once, but was due to a missing
chute protecter. I used cellulose wadding instead and the wadding
basically absorbed the ejection gases. Luckily, the rocket did a flat
spin until the main deployed.
[My answers based on the assumption that Brian is referring to the
launch I witnessed]
I disagree. I believe the electronics were damaged on a previous
flight, as I recall at least one altimeter had black powder residue on it.
While it can be hard on the motor, I don't think it made any difference.
Motor performance was optimal on the way up, as I recall.
One of the charges fired just as it was going beyond the hill, on the
way down, which means the altimeters armed. Not sure which one, though;
the rocket was moving WAY too fast at that point for it to be saved by
any recovery system.
The residue was from a leaky electronics bay. The one with residue
hada been sent to Missile Works for repair so it had been fully tested by
the manufacturer. (I had broke off a terminal at one point.)
I think pounding the motor in jarred something loose in the ejection
Yeah, I usually don't think too much about the cost of a rocket until
it gets lost or destroyed, then I can't think of anything else. Losing
'em is much worse than crashing them too. At least when they crash, you
can salvage stuff from it, and you don't have to waste time looking for
it or worrying about it. But when it's lost, you can't get anything
back, and you know that it's just sitting out there somewhere in good
condition, taunting you. ;)
I lost two complete rockets with camera payloads in the badlands last
year. That's four parachutes, two sets of motor hardware, two cameras,
two servo mechanisms, two tail sections that even after a year may only
need to be cleaned up and repainted, two kevlar shock cords, and two
rolls of film which probably still have some cool photos. I've spent
many days and nights looking for them, no luck at all so far. It's
On 5 Jun 2005 13:48:00 -0700, " email@example.com"
I had that happen on my first mid-power rocket Last December. I had
previously only launched Estes-type models, but bought and built a LOC
Starburst. Since this would be the biggest motor I'd used to that
point I also bought a PerfectFlite alt in it to see how high it would
go. On its maiden voyage it had a beautiful launch and flight,
deployment was smooth, and we watched it land...more than half a mile
away. That was my first launch that day, and I spent the next 2-3
hours in 30 degree weather looking for it(and seemingly finding every
damn hidden puddle in the area). No joy. So between the cost of the
kit and the alt, I probably lost about $130 worth of stuff. Nowhere
*near* what some of you guys spend, but a pisser for someone who
hadn't spent more than about $20 on a bird before.
A beeper might have helped you with this one. Been experimenting with
them and had a Super Nova Payloader go in some tall grass on an E30-7.
Chased the model and saw it miss the treeline as I had a good line of
sight fix. I picked up the beeper but thought I would keep walking to
where I thought the model was. I stopped where I thought it went done
and the beeper suggested it was off to the left. I turned to the left
and followed the sound and found that the model was 60' from where I
thought it was.
If I didn't have the beeper on board, it might have taken me a long
time to find. They are mandatory for me if I am uncertain as to how a
model will behave.
I use the same types of beepers in your article. They help but the sound
doesn't carry as far as you would think once the bird has landed. Also, it
helps to beef them up with Kevlar loops and such. I have had a couple of
them fall off - deployment is tough on them.
What has helped me more than anything is a handheld GPS in conjunction with
the beeper. It works everytime, so long as you can see it come down and get
a compass heading on it. I use the GPS to walk a straight line to it. It
gets you close enough to hear the beeper anyhow.
I agree, beepers are much better than trying to find a rocket by using the
"by gosh and by golly" method. I've tried the BGBG method before, and
that's when I end up losing stuff! 8-). It's always advisable to have a
recovery plan. (i.e., beepers, rocket hunter, GPS) Stumbling around out in
the weeds looking for stuff when you already have that sinking feeling that
it's gone for good sucks. That's my least favorite part of the hobby.
Try to convince your club to buy the receiver. (Unless you don't fly with
the same club all the time.)
The receiever is pretty darn pricey. Our club owns the receiver and we
have at least a dozen transmitters amongst club members. The prefect
often loans out his transmitters.
We have never lost a transmitter. We have lost rockets because the
transmitter wasn't attached well enough. Two transmitters have been
destroyed in lawn darts.
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