Wiring Ejection Charges

Cranny Dane wrote:


Weapons of Mass Destruction team
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Interesting they call it that in today's times.
Which agency out of that list has this team ?
CD
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Cranny Dane wrote:

Ramsey County
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Interesting that local directed patrol, or commonly called Metro in the old days, needs a WMD team.
If a real WMD was found in my county, I sure would not want the county sheriff or our metro squad taking care of it ;)
But times do change, perhaps it's the definition of a WMD ?
CD
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Cranny Dane wrote:

The legal definition of "WMD" is incredibly broad (In the US, anyway). It includes everything from hand grenades to spud guns (rifles with barrels larger than 1/2in). It would include many high power rockets, if not for the 'intended for sport use' exception.
I'll see if I can dig up the actual wording.
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that's the definition of a "destructive device", not a mass destruction ;)
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Thanks John,
I had not seen DD added to the WMD code before.
I wonder how "destructive device" got morphed into WMD ?
Also, some have class three licenses to own DDs like an M240, so now they also own WMDs ?
And Spud guns like you said are now WMDs.....
ok, I'll follow my own advice, follow the money trail.
Funding for preventing WMDs will happen easier then funding for preventing destructive devices.
That also makes the person whose name shall not be mentioned on r.m.r. guilty of brandishing a WMD.....
CD
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wrote:

If I see the guy walking towards me I wave to make sure he sees me and the rocket, then wait for him so we both can talk about the flights on the way in. If I don't see anyone, I radio the LSO to let them know or get a good bearing and let them know when I get back. If I had the room to bring it in, I would not stick any body parts in or in front of the body tubes.
If my rocket has landed hidden in a corn field, hung up in a tree or powerline, then I've launched under conditions which present a hazard to its recovery and violate the safety code.

Same as the liability if the rocket falls from the sky and injures someone or damages property (possibly less if the club rules prohibit recovery of other's rockets, but you would still pay).
There is no power to the device when the RSO is checking my rocket, unless he is standing at the pad with me.
What happens when your rocket has landed face down hiding the warning, screw and vent hole.
The logical conclusion to this line of argument is that all rockets which use a pyrotechnic device for recovery be painted red with 3" yellow lettering indicating DANGER EXPLOSIVE HAZARD, DO NOT HANDLE on 4 sides (3 for 3 fin rockets).
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snipped-for-privacy@earthlink.net says...

I still maintain that if you are going to put anything on the outside of a pyro equipped rocket, it should be a big "Don't Touch This, Call This Number" with the owners cell number. Directions for disarming I see as an invitation to both a civilian being injured and a lawsuit.
--
Tweak

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Wow, you get to use the Cigar Tweak !
Best sticker wording my firm has seen ;)
Cranny Dane.
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wrote:

In these days of fear, paranoia, and extremism, the assumption would be to assume that it is an unexploded terrorist bomb. To be safe, use a robot to bring in a pound or so of HE and detonate it. Forensics can sort it out later. :(
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snipped-for-privacy@nospam.mchsi.com says...

Better than Joe Civilian getting punched in the gut by a nosecone followed with a "BP Face" chaser.
;-)
--
Tweak

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So, one of the themes of this thread seems to be that RF doesn't cause ejection charge accidents, user error does, particularly reverse battery errors. So why are we still using flight electronics that fails in a 'fire' mode when this error occurs?
GC
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Bob mentioned a idea for an altimeter which would safe itself after a time. For some reason it made me consider that while all motor recovery has been certified by an independent organization, none of the electronic recovery is. Specifications and required testing on avionic packages. Now that's starting to sound more like NASA.

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time.
Sorry, I missed something. What "independent organization" certified motor delays? I thought that was done by TMT, S&T and CAR. Not quite "independent".
And then it's only +/- 20%.
Seems the result of this discussion is that many of the problems were caused, not by the altimeter, but by errors by the flier. Maybe we should certify the fliers! (Oh, wait, I think we do!)
Could be that too many people get certified long before they should...
Hey, Kaplow flies happy meals, and has minimal HP experience. (as does most of the NARBOT, it seems). I still can't understand why he's so vocal in this thread, other than he's just being "kaplow".
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says...

That's what you get. Fliers with minimal/no HP experience recommending sweeping changes, some of which would serve to increase the risk of inflight failure by adding complexity in order to "child proof" HPR. If you can't wire a battery properly then you have no business flying anything bigger than a happy meal.
I don't get why we want to emulate NASA, either. They can't even convert metric to english.
Unless by emulating NASA they mean spend as much money as possible to make failures that much more painful.
--
Tweak

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AZWoody wrote:

Really? I thought most of them were HPR certified.
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What ever gave you that idea? I See Bob on a fairly regular basis at luanches sense 1999. Yes he likes to fly his Estes size creations, but I have seen plenty of HPR out of him.
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Nobody mentioned static electricity. I've seen one inadvertant firing after impact that was probably static induced. At a night launch, one flier had his drogue deploy, but not the main. When he picked up the rocket, the main ejection charge fired.
Glen Overby, kc0iyt
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wrote:

What is the reason for thinking this was static electricity induced? Was there a noticeable spark? The rocket would have been lying on the ground and should have discharged any potential it had. The flier should similarly have been slogging about and been at Earth potential.
It seems other scenarios played out earlier in this thread were at least as likely a cause as static electricity.
For example an altimeter that didn't arm or sense properly for deployment, but got a pressure spike by the flier covering or uncovering a vent hole on the ground.
It seems to me that the weak link in all of the unexpected deployment scenarios is the electronics that are fooled into thinking "NOW" is the time. As a microelectronics engineer, I know that chip circuitry is susceptible to electronic noise. The amount of RF or static needed to trip a chip's logic would be a lot less than that needed to fire an e-match. A small transient, applied directly to a chip's sensor inputs, could make the chip believe the sensor was seeing an event.
Similarly, altimeter design that doesn't fail safe when power is transient could trigger the e-match. A design that powers up with a spike on the e- match outputs could set off the charge at arm time.
I'm not saying there are altimeters that do that, I'm just stating that the design of the system whose sole purpose is to light that match, should be the first suspect in any match lighting. Foot scuffing static electricity, or RF interference, directly lighting the match seems less likely than those sources fooling the electronics into doing the job.
ScottE
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