lost rockets and a reflection on costs

wrote:


Is that the motor ejection on the Hypertek (which doesn't have it) or the outboards that didn't light?
Something seems to be missing here.
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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

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Jerry Irvine, Box 1242, Claremont, California 91711 USA
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Jerry Irvine wrote:

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.
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writes:

a
which
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.

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Brian Elfert wrote:

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.
Dean
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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.

Baro.

Missileworks RRC2 and an Adept deployment controller.

Yes, they both flew with a Hypertech M in a different rocket the year before.

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.
Brian Elfert
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Brian Elfert wrote:

[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.
-Kevin
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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 system.
Brian Elfert
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Brian Elfert wrote:

Okay, I didn't know you had sent it in to MissleWorks for service. I'm sure Jim checked it out thoroughly before returning it to you.

If that's the case, I'd say there was a bad connection already that may have failed even under thrust.
-Kevin
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Electronically.
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Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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No "pounding" allowed on rockets.
--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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tater schuld wrote:

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 really frustrating!

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On 5 Jun 2005 13:48:00 -0700, " snipped-for-privacy@aol.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.
Eldred
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Eldred Pickett wrote:

Hi,
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.
Kurt
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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.
--
Joe Michel
NAR 82797 L2
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On Mon, 6 Jun 2005 22:16:04 -0500, "J.A. Michel"

I agree that the sound doesn't travel as far as you would think but they're still better than nothing.
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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.
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Joe Michel
NAR 82797 L2
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On Tue, 7 Jun 2005 16:36:17 -0500, "J.A. Michel"

Yeah but there's nothing like that feeling you get when you stumble onto it. 8-)
I have to get a Rocket Hunter one of these days.
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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.
Brian Elfert
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