# AT Hybrid motors

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#### Chilly

##### Well-Known Member
Except that I believe they are not back in production yet. It does look promising once they bring 'em back, though.

#### Zippy

##### Well-Known Member
It would be nice if they put one out in 29mm or even 38mm. The 54mm is just way too much motor for my needs. I like the way Aerotech does it though, no special (expensive) equiptment needed at the launch site.

#### n3tjm

##### Papa Elf
Aerotech hybrids beat the purpose of hybrid motors though....

They require a hazmat to ship.
Most of the loads require a LEUP.
The pyrotechic valve system is complex and I seen it fail more times then work (5 to 1 actually).
True you don't need expensive GSE, but there is other equipment that it needs that cost $. Hypertek is good if the club has GSE... and actually know how to use it. My hypertek experience has been bad too.. Then there is RATT WORKS, Plastic Polymers, and West Coast Hybrids... All of them are based off the ingenoius design that RATT WORKS came up with.... and I had great success with the Ratt works systems . #### Todd Moore ##### Well-Known Member Originally posted by n3tjm All of them are based off the ingenoius design that RATT WORKS came up with.... [/B] Actually, Bill Colburn and John Urbanski came up with that design, and Dave used it with permission from Bill. This desing was using plastic hose as a fill/burst apature, and a compression fitting as an injector. Dave may have come up with other enhancements on top of this, I'm not aware. I had thought he came up with the monotube design, but have have since heard that this is maybe not the case. If anyone else has any history on this, I'd be happy to know. Todd Moore #### UhClem ##### Well-Known Member Originally posted by n3tjm Aerotech hybrids beat the purpose of hybrid motors though.... They require a hazmat to ship. Most of the loads require a LEUP. The pyrotechic valve system is complex and I seen it fail more times then work (5 to 1 actually). True you don't need expensive GSE, but there is other equipment that it needs that cost$.

Hypertek is good if the club has GSE... and actually know how to use it. My hypertek experience has been bad too..

Then there is RATT WORKS, Plastic Polymers, and West Coast Hybrids... All of them are based off the ingenoius design that RATT WORKS came up with.... and I had great success with the Ratt works systems .
The J145, J170, and J210 reloads contain less APCP than an F motor. The J260 and J390 reloads have 2 and 5, respectively, 62.5 gram slugs of APCP each. This puts them firmly in the same category as the other Aerotech Easy Access reloads. The K and M reloads are regular J and L APCP reloads and have APCP grains well over 62.5 grams.

So only the K and M reloads requires a LEUP. Unless you believe the BATFE FUD about greater than 62.5 gram assembled weight. In which case only the J145, J170, and J210 are LEUP free.

The pyrovalve has worked perfectly for me. The only problem I have seen is a failure to tighten the flight tank until the pin valve opens. I did this once and saw someone else do it once. After replacing the pyrovalve components (the pyrovalve worked fine and was consumed, Aerotech has a kit of parts for this) and tightening the tank fully, the motor worked fine.

The most likely pyrovalve failure mode is incorrect ignitor placement. It must be all the way up to the pyrovalve. Unfortunately, the preheater grain core makes for a very small target when inserting an ignitor. While watching Gary Rosenfield assemble some hybrids, I noticed that he used a knife to chamfer the core of the preheater. This created a much larger target for the ignitor. Once I started doing that, I had no trouble inserting ignitors at the <A HREF="https://home.earthlink.net/~david.schultz/level3/erint/flightlog/bigpictures/18Novignitor.jpg">pad</A>.

As for GSE, you end up with two pieces of single use hardware: a nitrous tank and fillhose. You also need a decent scale to weigh the flight tank but I use that for so many other things now that I can hardly consider it dedicated GSE anymore. If you decide to add a NOS system to your car then only the fill hose is dedicated GSE.

Dave, happy user of Aerotech hybrids since 1997.