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Chuck Rudy

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One thing I was wondering of was the kiddie pool under the rocket, I saw it filled and the blob of plastic which was left. Finally I got an explanation of the pics...........

"This is how Wedge explained it... The trailer-mounter launch rail originally had a 45 degree angled blast deflector on it (to protect the trailer wheels and stuff from getting toasted). However, the 3 P motors igniting simultaneously were producing something like 6000 pounds of thrust, and he was worried about sending the trailer shooting off to the side! So his idea was to remove the blast deflector completely and put 100 gallons of water in a kiddie pool under the nozzles. Sort of like the Saturn V/Shuttle water deluge system, I guess. Anyway, apart from vaporizing the kiddie pool, it worked like a charm. The trailer was unscathed (from *that* flight anyway!) and as a bonus, it produced a pretty spectacular liftoff cloud." --Greg L.

Thanks to Greg for the explanation.
 

llickteig1

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I noticed the pool and had figured that the water was just to add to the overall effect; as in extra smoke (steam). I hadn't thought about the pragmatic need to absorb some of the blast.

--Lance.
 

nialloswald

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Did you see the photos of the plastic toys that were floating in that pool?

I found the videos again tonight (managed to download them on another PC before the bandwidth issue, found them in Temporary Internet Files) and the thing that really strikes me is that ignition was very very fast. Videos of large AT AP motors (like 75mm M's) show slow ignition, but those three P motors seem to ignite and pressurize instantly on the video. The rocket certainly starts to move very quickly too.
 

solrules

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Originally posted by nialloswald
Did you see the photos of the plastic toys that were floating in that pool?

I found the videos again tonight (managed to download them on another PC before the bandwidth issue, found them in Temporary Internet Files) and the thing that really strikes me is that ignition was very very fast. Videos of large AT AP motors (like 75mm M's) show slow ignition, but those three P motors seem to ignite and pressurize instantly on the video. The rocket certainly starts to move very quickly too.
Did you see those beasty igniters that they used? One of those could pressurize a mansion ;)

If I remember correctly, they used a 38mm BT grain and drilled 6 holes in it. In each hole was a super hot igniter.
 

rocwizard

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Originally posted by nialloswald
the thing that really strikes me is that ignition was very very fast. Videos of large AT AP motors (like 75mm M's) show slow ignition, but those three P motors seem to ignite and pressurize instantly on the video. The rocket certainly starts to move very quickly too.
Thermite ignitors were what profided the instantaneous ignition. Thermite is good stuff if you use it correctly:cool:
 

nialloswald

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Yeah, I read about it on the site a while ago. They did testing with a pressure gauge IIRC to ensure that those three huge motors would light instantly.

I remember the thermite demo at school - v ery impressive, but it went through the bottom of the crucible and put balls of molten iron all over the floor! Nice stuff!
 

Loki

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Originally posted by solrules
Did you see those beasty igniters that they used? One of those could pressurize a mansion ;)

If I remember correctly, they used a 38mm BT grain and drilled 6 holes in it. In each hole was a super hot igniter.
You must be thinking of another rocket.

While using AT propellant for a Loki motor igniter has its humourous side, that's not how we lit the Black Brant motors.

Copper thermite igniters were used. Copper thermite is a powder that was rolled up in a baggie containing two electric matches. When initiated, the thermite reaction creates a very hot (10,000 degrees) cloud of copper metal vapor. The vapor fills the motor core and quickly condenses into small globules of liquid copper. These coat the propellant surface and ignite the propellant. After firing I often find copper residue on the bulkhead, nozzle, and sometimes the launch pad. If you single frame the videos you'll see that the motors come up to pressure in only one video frame. You see a copper plasma ball in one frame and in the next frame the rocket is moving up the launch rail.
 

Ryan S.

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Originally posted by Loki
You must be thinking of another rocket.

While using AT propellant for a Loki motor igniter has its humourous side, that's not how we lit the Black Brant motors.

LOL!!!
 

solrules

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Originally posted by Loki
You must be thinking of another rocket.

While using AT propellant for a Loki motor igniter has its humourous side, that's not how we lit the Black Brant motors.

Copper thermite igniters were used. Copper thermite is a powder that was rolled up in a baggie containing two electric matches. When initiated, the thermite reaction creates a very hot (10,000 degrees) cloud of copper metal vapor. The vapor fills the motor core and quickly condenses into small globules of liquid copper. These coat the propellant surface and ignite the propellant. After firing I often find copper residue on the bulkhead, nozzle, and sometimes the launch pad. If you single frame the videos you'll see that the motors come up to pressure in only one video frame. You see a copper plasma ball in one frame and in the next frame the rocket is moving up the launch rail.
Hmm. It was on their site, the google cache is:

https://www.google.com/search?q=cac...tm+igniter+site:blackbrant2.com&hl=en&start=1

. I guess I had not checked the igniter page recently, but wasn't the inital plan to use a 38mm grain? Thermite was evidently a much better option.
 

Chuck Rudy

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I recall seeing on their site a drawing of a slug with 6 holes drilled on it's exterior filled with pyrogen and one central hole for the main ignitor lead. It may have been an older idea of Wedge's, and no one will get to see it until his bandwidth problem is reset. Thermalite made it obsolete.

Chuck
 

Ryan S.

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yes, his first idea was to take a 38mm BT grain and drill a central core and fill that wil pyrodex pellets, then drill 6 holes on the outside and put dipped ematches in them. He tested it and it didnt really work
 

Chuck Rudy

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Originally posted by Ryan S.
yes, his first idea was to take a 38mm BT grain and drill a central core and fill that wil pyrodex pellets, then drill 6 holes on the outside and put dipped ematches in them. He tested it and it didnt really work
It was obviously a Loki 38mm slug he was looking to use. ;-)
 

Ryan S.

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no doubt ;)

btw that description is what I remembered from the website
 
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