homemade igniters directly in lift charge

[brad224]

i’ve seen lots of info on fusing home built shells, and thats the way i always used to do it, but i have to admit that i was never crazy about the concept of lighting a fuse and then backing away in a hurry in the dark.  for the past year i’ve been making nicad igniters, putting the end into my burst charge, (essentially a bottom fuse) and then “igniting” from a safe distance with my electronic firing system.  seems to work like a charm, and no tripping in the dark.  i can set up an entire rack (or two) and launch them all remotely without having to manually light anything.  are others doing this too?  

[cmjlab]

Are you using any kind of sheath for your match (as are found on purchased ematch)?  

I put the ematch into a short quickmatch pipe extension so I don't have to worry about lift granules getting in and rubbing against the ematch head which is friction and impact sensitive, and potentially lighting the lift charge in my hands.

This allows the shell to be in the mortar, and my face and hands to not be directly over the mortar if something happens and it does go off - instead it would launch as planned (just a bit earlier), and I'd likely not be injured nearly as bad as if I was holding the firework when the lift goes off goes off.

The drawback being that it adds a couple milliseconds from when you push the fire button, to when the lift actually ignites....but it shouldn't be an issue unless you're doing a pyromusical (but then you could add that time in the software, so even then not really).

[Arthur]

Traditional fireworks had slow fuses to give a few (3 - 5 ish seconds) between firing the fuse and the effect functioning. This works with skilled people and the general public.

For professional shows especially if sync'd to music electric firing is used. A modern e-match should function within milli-seconds, electric delays may be used to compensate for the time it takes to see the firework and hear the soundtrack according to the distance to the audience. (speed of light compared to speed of sound).

[brad224]

my “ematch” is home twisted nichrome wire wrapped and crimped.  no pyrogen, but  i poke a little hole in a half inch piece of medium speed pink visco, run the nichrome loop through the fuse, and secure it with a little bit of masking tape.  that goes directly into the lift charge and then gets hooked up (through the hdpe launch tube in the rack.  sorry, but 3-5 seconds to back away in the dark just doesn’t do it for me.  guess i’m too clumsy and feeble.  shot 6 test shells when it got dark tonight.  no ignition failures.   a couple spollettes were half a second too long, but no failures to launch or failures to ignite.

[cmjlab]

Gotcha, I've never used a plain nichrome wire as an ignitor, but you can disregard everything I said then.