Just Thinking

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.

It's not only possible, it's almost a certainty. And it's just as arbitrary as their attempted regulation of rocket motors.

M

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.

Who knows, maybe flashbulbs will make a comeback! ;-)

Know of any good pyrogen recipes?

Ted Novak TRA#5512 IEAS#75

Real fine steel wool works similarly. I test with it sometimes. Also there are many more filaments than crummy xmas bulbs.

Phil

and potassium perchlorate needed for pyrogen.

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.

Got all of the above except the PP but I do have KN03.

Ted Novak TRA#5512 IEAS#75

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.

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).

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:

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.

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 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.

Or they'll do an end run and regulate rockets per se through HSA by redefining "destructive devices."

Which will still cause ATF no end of grief as they realize pop bottle water rockets have more than 62.5 grams of propellant. And as people revert to 'pirate' launches and stealth rockets and a hundred other cracks in the dam all leading to a far greater mess than ATF now has on its hands with APCP.

ATF: The neolithic "uunnnh, just smash it with a rock" attitude.

The same mentality which a group of fishermen once used to deal with starfish. They cut them up into pieces and threw the starfish pieces overboard. Not realizing that any piece with a portion of the center could regenerate into a whole new starfish. And then they wondered why there were so many more starfish than before clogging their drag nets...

+McG+

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

Try pulverizing equal parts unconstitutional regulations and JBGTs.

Negatory, not hot enough to light Black Jacks :)

Ted Novak TRA#5512 IEAS#75

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

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.