Just Thinking

Just thinking - Is it possible the ATFE expects to lose the lawsuit about APCP so instead they will try to shut down HPR by regulating ignitors as explosives? It seems logical to me. After all, if we can't get ignitors to ignite our "legal" rocket motors, then the ATFE still wins in the end. Putting HPR out of business will not increase "security" one iota. Aren't there any politicians in Washington who will argue forcefully against this nonsense? I guess not. Both Republicans and Democrats cringe in mortal fear of being called "soft on terror." Larry Lobdell Jr.

On 17 Sep 2006 00:10:02 -0700, "Larry Lobdell Jr."
  Quoted Text Here  
Not at all. The war in Iraq and our exploding national debt seriously limits or ability to fight terrorism, not to mention the imminent nuclear threat of North Korea, and the emerging nuclear threat of Iran. The Republicans don't care about the national debt, balance of trade deficit, etc. that should enable the US to be tough on terror, and security in general. It would be ironic and tragic if terrorists and gross US financial mismanagement brought the US down, similar to the cold war collapse of the USSR. King Bush it seems, is most concerned about his ability to dictate how "prisoners" (or whatever they call them this week) are tortured (or interrogated, or whatever they call it this week). But enough BS...
Sport rocket motor igniters are such a non issue because the current regs do not require the motors to be ignited with manufactured ignitors that may require storage and lecencing/permitting as explosives. You can still make and use your own as long as you initiate them remotely by electrical means.

Larry Lobdell Jr. wrote:
  Quoted Text Here  
It's not only possible, it's almost a certainty. And it's just as arbitrary as their attempted regulation of rocket motors.
M

snipped-for-privacy@aol.com wrote:
  Quoted Text Here  
They can regulate pre-made igniters, but they can't regulate the components. Nichrome wire is made on an industrial scale and is trivial to obtain, as are the small quantities of nitrocellulose, Aluminum (or magnesium) powder and potassium perchlorate needed for pyrogen.

Brian McDermott wrote:
  Quoted Text Here  
Who knows, maybe flashbulbs will make a comeback! ;-)

Real fine steel wool works similarly. I test with it sometimes. Also there are many more filaments than crummy xmas bulbs.
Phil
On Sun, 17 Sep 2006 19:21:33 -0400, "Darrell D. Mobley"
and potassium perchlorate needed for pyrogen.
  Quoted Text Here  

Brian McDermott wrote:
  Quoted Text Here  
Know of any good pyrogen recipes?
Ted Novak TRA#5512 IEAS#75

the notorious t-e-d wrote:
  Quoted Text Here  
A good hot pyrogen can be made with a few rule of thumb considerations. You generally don't need exact percentages or accurate balances, unlike EX rocketry where +/- 1% can have a substantial impact on flight performance.
In general, a 50/50 (by mass) mix of a metal powder and Potassium Perchlorate (bound with ping pong ball NC lacquer) makes a nice pyrogen. I used this for a while and it would light blackjack propellant the instant you touched the launch button. A little bit of titanium mixed in the pyrogen makes for lots of hot sparks that further aids in ignition. All the chemicals (or even igniter kits) can be purchased from Firefox, and you're free to experiment.

Brian McDermott wrote:
  Quoted Text Here  
Got all of the above except the PP but I do have KN03.
Ted Novak TRA#5512 IEAS#75

the notorious t-e-d wrote:
<edited for brevity, snip>
  Quoted Text Here  
<snip>
http://www.nakka-rocketry.net /
Scroll down the main page to the motors section. He's an EX guy, but there are few out there with more technical understanding of what they are doing in EX, or Sport, rocketry.

the notorious t-e-d wrote:
  Quoted Text Here  
The decomposition of KNO3 in pyrotechnic mixtures is endothermic (re: a positive heat of reaction), so those compositions tend not to be as energetic as those with Perchlorate, which has a slightly negative heat of reaction (decomposition is exothermic). Chlorate has a large negative heat of reaction, which leads to easily initiated mixtures, which is clearly a double-edged sword and even a possible safety issue in some cases. KNO3 will work fine, but it's not as hot as the other two. If you have charcoal and sulfur, you could try a crude black powder pyrogen.
And it should go without saying that one should never ever mix the powder components while they are dry. Add them one by one to the binder, making sure they are completely wet before adding the next ingredient.

Brian McDermott wrote:
  Quoted Text Here  
Ok, that makes sense. I've been itching to try out a new pyrogen recipe from scratch.
I have plenty of KN03, red/black iron oxide, iron flakes and aluminum powder. I figure I could come up with a decent pyrogen mix with what I have but wanted to check with others on what they are using first.
Thanx for the tip.
Ted Novak TRA#5512 IEAS#75

  Quoted Text Here  
(NEW MESSAGE)
Hey,
I can't stress how important it is to mix the powders with a wetting agent (binder) ping pong ball lacquer, nitrocellulose lacquer, dibutyl phthalate as the potassium perchlorates and chlorates can be very sensitive to being set off by friction. I read where the Palestinian suicide bombers tried to use potassium chlorate based explosives and it would explode too early on them leading to an early ticket to heaven. ;-)
A reasonable igniter can be made by simply taking 4.42gms. of copper oxide (CuO) and 1 gms. of aluminum powder. Get the finest powder you can find. (use Ebay) Use the 4.42 : 1 weight ratio to mix larger amounts, mix it up well in ping pong ball lacquer and use 30 to 32 gauge nichrome wire. It will ignite pretty well without the use of oxidizers. This of course requires a 12V launch system and there might be a one to two second delay before the igniter flares but it works. I wouldn't use it for a drag race but I highly recommend you give it to the competition! :-)
Kurt

instead of destroying ping pong balls why not get some Deft or Parks Lacquer and bind the pyrogen with that? its nitrocellouse lacquer as well. Nitrocellouse lacquer is trival to obtain anyways, guitar and furniture refinishers use them all the time. Unless you are from PRK (California) where those things might be banned due to enviromental concerns. However that is usually for industrial stuff, no one cares about what u do in garage. I dont know where to get Pot Perchlorate except chemical store and they might be somewhat suspicous as to why you need them.

Oh and if you want to do an igniterman style igniters where a conductive primer is used, thus you wont need to try and solder a bridge wire, take a look at this: http://www.stewmac.com/shop/Electronics,_pickups/Supplies:_Shielding/Conductive_Shielding_Paint.html
1/2 pint should be enough for assloads of igniter. This product is intended for shielding electric guitars where the thing is painted inside the control cavity of the guitar and connected to ground so the guitar wont hum like crazy. It is esentially carbon conductive paint, if you bridge the wire with a small amount of space it should heat up if you pass an insane amount of power though it. Then you would obviously let it dry then dip into your pyrogen mix. I have used this product as intended (to shield guitars) and I havent tested its application for igniters, so test it before using it in the field!
Some made their own conductive primer by taking some graphite lube and mix it in nitrocellouse lacquer. Firefox also sells daveyfire chips and conductive primers as well.

  Quoted Text Here  
Try pulverizing equal parts unconstitutional regulations and JBGTs.

Bob Kaplow wrote:
  Quoted Text Here  
Negatory, not hot enough to light Black Jacks :)
Ted Novak TRA#5512 IEAS#75

Brian McDermott wrote:
  Quoted Text Here  
A while back I made the comment that this increase in regulation may actually be a good thing for our hobby. It will force us to be more innovative and explore other technologies (such as hybrids).

  Quoted Text Here  
Alex, your hybrid flight at the AARG launch was one of the coolest I have ever seen! Any ideas what causes the spike in thrust just after liftoff? It was very impressive! Did anyone get it on tape?
Tad http://www.rocketryplanet.com/

Tad Danley wrote:
  Quoted Text Here  
Why thank you! I assume you mean the RATTworks K240 at the September launch. To be honest, the flight I had in McGregor this March was even better. No hesitation at all. That motor has such a unique sound to it!
I suspect the motor was a bit sluggish off the rail because the preheater grain I was using was a bit small (1/2" thick instead of the 3/4" I used in March). The motor just wasn't hot enough at first. But the overall performance of the flight was right where the simulations predicted (March's flight was "hot", a bit over simulation).
For October (or November if I don't get to it) I want to try a Hypertek style ignition using O2.
This is what I mean by "innovate". Try different techniques. Use different materials. Evolve.