Copperheads & Aerotech...any tips?

Phil,
How about monotube hybrids, which must be assembled with the igniter in place? Since it's not an assembled engine until the N2O is added, will you inspect them with the igniter in place?
Kevin OCassen

On Sat, 07 Oct 2006 07:55:09 GMT, "Kevin OClassen"
  Quoted Text Here  
As I mentioned in my original post, I can be flexible. You mention a valid reason. - But don't tell the guys that accuse me of working for ATF. I'm way less likely to be flexible with one of them - unless they give me what I consider a valid reason to be. And that is a capital / bold / emphasized I - like it or not. I don't look to bust balls - just to minimize the possibility of bad things happening.
SO; how many people put an ignitor in before the rocket is vertical?
How many people put clips on their ignitor before the rocket is verticle?
How many people short the clips together berfore they clip onto the ignitor?
Did you know that a relay can be stuck in a way that will put power to the ignitor as soon as you touch it with the clips. This can be cause by a mechanical malfunction or from the contacts getting welded together.
Phil Phil

Phil Stein wrote:
  Quoted Text Here  
I do. Every time.
  Quoted Text Here  
Never.
Always!
That's why I touch the clips together to verify that exact same scenario.
Ted Novak TRA#5512 IEAS#75

  Quoted Text Here  
Why are people launching in violation of the safety code?
There must be a safety interlock in series with the launch switch. In a relay system, that is the relay.
No safety in series with the relay is far WORSE than walking around with an igniter in the motor. I've seen 2 HPR motors go off in the fliers face because the controller did not have this simple safety feature. You can read about one of them there: http://www.vatsaas.org/rtv/lessons/hotwire.aspx
  Quoted Text Here  

  Quoted Text Here  
If everything is operating correctly and the system confirms to out safety rules, it should not happen. When there is a malfunction in the system, bad things can happen.
Phil

  Quoted Text Here  
No, the switch is the switch. The safety key has to be somewhere where it can be inserted and removed from a safe distance, which means not at the pad.
If you REALLY want safety at the pad, the unplug the firing leads from the box before connecting to the ignitor, and reconect them after you've cleared the pad. Or remove the power connection from the relay box while connecting the ignitor.

Bob Kaplow wrote:
  Quoted Text Here  
Totally agree.. it should be back at the flight line.

writes:
  Quoted Text Here  
Absolutely. So you must have another wire feeding the pad box to provide the removable interlock. Motor with a pull pin perhaps.

writes:
  Quoted Text Here  
No, a closed launch switch allows current flow to the igniter, and an open one prevents it. In a relay launch circuit, that is the relay. Closing the relay launches the rocket, does it not. What the single relay circuit people call the launch switch is simply a 10' pole that presses the launch switch.
No single relay system has a safety interlock because an interlock must prevent current from reaching the igniters.
Nothing in those single relay systems prevents current from reaching the igniters.
They do not conform to NFPA guidelines and are inherently unsafe. Searches will turn up many stores of when they fail, they fail closed (shorted). "Bad things can happen" as Phil said BECAUSE they do not have a safety interlock. If the system did have a safety interlock and the launch switch (the relay) was shorted, the rocket would launch when the person installed the safety key.
Would you like a worse design than the single relay? Use only 1 battery. If you have someone launching rockets with a single battery relay controller, you best point out a sort within the pad box completely rules out the "relay control box". A fire at our field uncovered that niffty feature.
  Quoted Text Here  

  Quoted Text Here  
The Pratt Hobbies Universal Launch System, a relay based system, does have a safety interlock at the pad, complete with warning buzzer. I still short the clips together every time before hooking them up.
Kevin OClassen

If a motor goes off in my face, I will be the poster child for why you do not install igniters in modroc motors before they are vertical. You can say that Tom Koszuta would not have had this happen if he listened to Phil.
My point is simple: don't treat modrocs like HPR You are enforcing rules that do not exist. Installation of HPR iginters is in the NAR safety code. Installation of modroc igniters is not. This is not my opinion, it is fact.
I don't RSO. I've done some very limited LCO. My volunteer work is that I hang around on Sunday after the last lauch to help breakdown. I usually don't get to the site early enough on Saturday (or Friday) to help setup, but sometimes I do.
wrote:
  Quoted Text Here  

On Sat, 7 Oct 2006 15:11:54 -0400, "Thomas Koszuta"
  Quoted Text Here  
As I mentioned I do have some flexibility.
I'm usually not at RSO more than 2-4 hours unless it is at PARA. There, I usually do it all day. If you are determined to put that ignitor in because the rules don't say you can't, find a different RSO.
If you haven't done it, don't tell me how to do it. If you don't like it tough s..t.
Phil

If you want to avoid it lighting by itself short the lead until its ready for launch. For crapperheads you will have to use a microclip or something....

I think I've got it! :-) Tonight I tried inserting the ignitors from home, and found that if I use my laser pointer to first spot the slot, then mark where that slot is with my finger, I can slide the ignitor in. Much easier if I can see where the slot is and what angle of attack I need for inserting the ignitor. (I use the laser pointer as it gives me a nice bright spot on the propellent grain that seems to illuminate the entire grain.) Think what I'll do is just pre-insert ignitors into the motors I plan to use that day as a time saving measure.
My thanks for all the replies...I do have an AT clip, but I actually find tape on my micro clips (smooth jawed) seems to work better. I can get the clips on more quickly without undue bending of the fine copper ribbon. I'm intrigued by the Magnelites, though. I just might make up a batch by dipping the pyrogen onto coils of very fine nichrome wire. Might make for a smaller ignitor that is easier to insert for the times that the slots give me trouble. Should also be more reliable for clustering too. Craig

I like igniterman better... you can use any scrap wire you have laying around. As for laser pointers, make sure you use a 5 dollar 5 milliwatt red laser pointer!!! DO NOT use a wicked laser... not only you risk blinding yourself, but you might actually light the motor with the laser! (they are powerful enough to light matches, I can light match with mines)

Interesting...I didn't think ANY consumer pointer was that powerful! Thanks for the tip. Luckily, mine is a low power model. It's built into a ball point pen and previously I used it to torment...er play :-) with the dog (it bugs him when the spot lands on his paw and then darts under a chair...he goes sniffing after it, which begs the question...just what does a spot of light smell like! :-) ). Craig
  Quoted Text Here  

  Quoted Text Here  
Unlike cats, dogs seem to know where the light is coming from. My dog goes nuts as soon as the laser pointer (or maglite) is in my hand. And she even goes to the drawer that they are kept in, stares at the drawer, then at you, and will bark until you get the hint.
Recently I was in a room, and shined the laser UNDER the door and drove her nuts with that.
Of course you have to be careful. I heard a story from someoe who always shined the laser pointer onthe same spot on the wood kitchen floor. One day they left the dog alone, and he decided to find the spot, UNDER the floor. The supposedly indestructible floor. that the manufacturer witht he lifetime warranty couldn't believe had been destroyed by a dog.

  Quoted Text Here  
One of our cats will immediately look at me when I turn off the laser pointer while the other continues to look for the dot. Our dog isn't interested in the dot at all.
-- Roger

Roger Smith wrote:
  Quoted Text Here  
Where I live, we have some geckos that come out at night during the summer. I noticed that they will crawl toward the laser spot. I guess they think it is a bug.

try this one.... http://www.wickedlasers.com /
those greens are on the order of 55mw or 75mw and stuff... they will light matches. I have the 55mw ones, and I tweaked it a bit by turning the pot and now it lights matches in less than one second. It will warm up though the site has listed its duty as 100 second on and 10 second off. Dont look into it, it will blind you faster than you can blink. And dont ever shine them into motor grains because they are dark colored and absorbs green quite well... if you do manage to light it they will most likely chuff but you never know... Some people have reported to light black powder with this...