I now use E-matches in D12's held in place by Scotch Adhesive Putty (poster putty). The prep is fast and ignition has been 100% up to 6 motor clusters. The long lead wires make parallel wiring easy, but I have been told that wiring in series with E-matches will work.
Thank you for the putty advice! I have been using the MJG blackpowder ematch starters; although they burst reliably, I've had a hard time keeping them fixed in the shallow ignition dimple of those endgrain motors.
In two flights of a 7 x 18mm cluster, I've had 13 motors light, but all 14 ematches burn. The one motor that didn't light was the one that had the most tension on its wires on the first flight, and the ematches having only been held in with blue tape, I surmise it had fallen out of the nozzle by the time I pressed play on the controller.
On the next flight I spent an inordinate time trying to hold the ematches steady with just the right amount of balled-up recovery wadding to tamp them in place, followed by an overdose of blue tape. Yet even the smallest jiggle of the wires forced me to retamp ematches and add more tape. And more tape, and more tape. In the end, the flight was a success, but your method sound
much better.
As a starting point for my experiements, how much putty do you use for each ematch, and how do you go about applying it?
Even if I hold the ematches in, I still have some way to go in understanding how to fire my seven motors reliably, since my relay controller (powered by a lead-acid Odyssey powersports battery out of a project car) seems to work sometimes and not others with the launch controllers I have (basic Estes and Estes E) and wouldn't work at all with the controller at a club launch last weekend (we eventually got the rocket off the pad by eschewing the relay controller and using long jumper cables with a giant LiPo a friend supplied).
Yet the relay controller worked fine both in earlier pre-launch testing and in the first test launch, and it also worked fine in later testing. Then in still later testing did not. Then it did again. When I realized how much money I was burning testing seven to ten ematches at a time without a consistent result, I realized I should be testing with my multimeter instead. Which I've been looking for (and for my backup too!) all week.
Something else I need the multimeter to diagnose: my basic Estes launch controller can check continuity of the MJG blackpoweder starter without firing it, but the E controller needs several ematches at a time before it doesn't fire them with a continuity check. Maybe my E controller is faulty?
Well, I might be able to tell soon, because I remembered that my good multimeter is in the glove box of a project car parked on a friend's farm 50 km from my house. Maybe I'll have a chance to drive out and get it this weekend. Or buy another. (That car is actually where the battery I use for the relay launcher is from, oddly enough.)
The strangest problems in my life seem always to be electrical . . .
