Mid Power Airstart Igniters

[marvSRG]

As you all know, I'm a cluster freak. But I have an airstart cluster question. I know that Magnelites, Fire-in-the-Holes, and sometimes dipped Davey 28F's (when they fit) are great cluster igniters for midpower composite clusters...if you use more than 3 or 4 Magnelites you need a beefy system, but that's usually not a problem in groundstarting as long as you have a good club system w/a relay...but for airstarting midpower composites...what are good igniters to use?? I know Magnelites have a little bit too much current draw and voltage requirements for most timers/accelerometers....maybe single ones could be fired, but I'm looking for airstart CLUSTER igniters, and Mags can't do that. Dipped Daveys would work, but they don't fit into most MPR motors. I think I've heard of Fire-in-the-Holes (Trailing Edge Tech. tungsten igniters) working OK with electronics...would they do? Any other suggestions? Could someone at least explain and lay out some voltage/amperage requirements for airstart cluster igniters? I'm pretty good with ground start clusters, but I'm a little shabby on my airstart info....and I may have one coming up . I'm thinkin (1)G64 and (2)F21's or F20's to (2) F20's or F21's, and then (2) D12's or E9's to finish the job.... Thanx in advance...

 

[wyldbill]

I know a guy that uses a BP "slurry" for his clustered BP motors. Mix BP with some water, a little white or yellow glue and a <b>small</b> touch of dish soap to act as a surfactant. Put your BP Motors on a table nozzle up and fill the nozzle with the slurry until you get a small dome. Let it dry hard. Tape a DF28F (or even 28B) on the back end. He swears by 'em, YMMV.

As for Composites, painting the inside of the grain w/ pyrogen (for RMS loads) and/or a small chunk of thermolite tends to help.

Using a separate ignitor battery and adding a big fat Capacitor across the input will help your juice for mutiple high amp ignitors. You might also consider using a larger battery and a reed switch or small relay, triggered by the pyro out to do your heavy work.

FWIW,
-bill