Unexplained misfires isolated to one sequence

[traumamed]

I hope everyone had an awesome 4th! I can certainly say I am very happy with how my show went. I'm still getting this whole pyromusical thing down, but this was probably my first one that I felt truly satisfied with how the choreography turned out.

I had just one little snafu that I can't explain. My show had an approximately 5-second drum/rhythmic section that I had choreographed a series of 2 comets x4 launching at 45 degree angles, followed by 2 mines x2, then 2 willows with a mine effect x2. So basically, it was an angled rack of 16, 8 mortars per side, with each side lined up as 4 comets, then 2 mines, then 2 willows.

I wired this over 8 cues, so two shells per cue, in parallel, into a slat that went to a 72M. The igniters were run directly from the shells to the slat, no connectors or scab wire. Continuity checked out green before the show. The two shells were the only events on each cue. My 72M uses the LiPo battery and was verified 9P fully charged. However, not a single one of the 16 shells fired. Unfortunately, I did not have a chance to recheck continuity after the show due to imminent weather requiring rapid teardown, but all 16 igniters were still securely in the 8 cues on the slat after the show.

I am at a loss. All the other 10 cues on the slat fired fine, so I can't blame a connection between the 72M and the slat. I also can't blame a bad igniter or a mess-up on my part replacing the fuses in the shells with igniters because that obviously wouldn't affect all 16 shells. Nothing in the entire show was wired in series, so a parallel/series module incompatibility is out. There must be something common to the setup that caused the failure, but I don't know what it is. Ideas?

(Edited to add: I fired a few of the shells manually the next day, using the igniters I had already installed, and using the same slat and the same 72M, and they fired fine.)

[BMoore]

So you had a full slat of 18 igniters, 10 of which fired, 8 didn't and all 8 were on this same rack? Were you using initiatiors/e-match or tallons? What was the timing between the 8 shots? The only thing that pops into my mind is if the cues were overlapping on the pulse time (.10 seconds for e-match mode, 2 seconds for tallon mode). Sometimes if you have one igniter short out, other igniters within that same pulse time could fail. Other than that, since you were able to fire them manually off the same set up, it really seems like there could be something wrong in your script rather than with the equipment.

[traumamed]

So you had a full slat of 18 igniters, 10 of which fired, 8 didn't and all 8 were on this same rack? Were you using initiatiors/e-match or tallons? What was the timing between the 8 shots? The only thing that pops into my mind is if the cues were overlapping on the pulse time (.10 seconds for e-match mode, 2 seconds for tallon mode). Sometimes if you have one igniter short out, other igniters within that same pulse time could fail. Other than that, since you were able to fire them manually off the same set up, it really seems like there could be something wrong in your script rather than with the equipment.

Ahh, the timing in the script must be it. I was using MJG initiators in those shells. However, I did have a couple of talons wired into that set of 18 cues on the 72M, so I had it set to a two-second pulse instead of the standard 0.1 second. There was only ~0.6 second between each event in that script sequence, so the overlapping pulse time must have been the issue. It is still kind of interesting that the very first event in the sequence didn't fire. Nonetheless, I can see how this would pose a problem. Lesson learned. Thanks for the response!