Clustering 18mm AT RMS motors

I have a Launch Pad Type 30 that has a 5 cluster MMT 1-24 and 4-18). I am thinking of purchasing the 18mm RMS motors but have a question about the type of igniter.

I have a 24mm RMS case and have noticed that the slot in the propellent grain is a little tight for the supplied copperhead igniter and can only guess that it is the same on the 18mm RMS motors.

SO...it's either cluster with the copperheads or see if something like the QuickBurst igniters will fit.

Any thoughts??

Also see current thread in the Propulsion forum on igniters for small AP motors (for some reason the 'insert link' function isn't working for me today).
-Jim
P.S. 5 X D =F+ is kinda getting out of the low-power arena.

I have had successful, INSTANT ignition on a pair of D13's (clustered) with slightly shaved Quickburst Twiggys built into the motor. It would take a LOT of current to fire 5-6 of them though...

Make sure you have an ignition system that will supply 100 amps if you plan to use copperheads. That's the current that 5 copperheads will draw when fired in parallel. https://www.gwiz-partners.com/igniters.pdf

I would suggest QuickBurst Poppers as a minimum current solution, but you still will need a relay launcher. A customer is quoted on the QuickBurst website as saying: "Holy moley. Six F72's - instant ignition leading to the most complete shred I have ever witnessed." Sounds like they will work. https://quickburst.net/popper.htm

Bob Krech

I wouldn't try copperheads. However, the Quickburst Twiggys will still draw >10A each, requiring huge current to fire. The poppers do sound like the best choice.

Thanks for all the tips. I'll have to take a look at the Poppers to see if theywill fit otherwise Thermilight sounds like the way to go.

And for the record it is 30 epoxy throughout and Bass wood, TTW fins. Puts out quite a plume. I'll send up a pic soon.

Admin - Please move this thread if you think it best.

Originally posted by cjl
I wouldn't try copperheads. However, the Quickburst Twiggys will still draw >10A each, requiring huge current to fire. The poppers do sound like the best choice.

Click to expand...

Here's an interesting report I found that discusses current draw of some igniters. igniter current draw report Unfortunately it doesn't include some of those under discussion in this thread, but still gives some insight into the behaviour of an igniter, and describes what appears to be a solid method of measuring their current draw.
Note that even the Estes igniter had a peak current draw of over 12A at 12V.
-Jim

Originally posted by RimfireJim
Here's an interesting report I found that discusses current draw of some igniters. igniter current draw report Unfortunately it doesn't include some of those under discussion in this thread, but still gives some insight into the behaviour of an igniter, and describes what appears to be a solid method of measuring their current draw.
Note that even the Estes igniter had a peak current draw of over 12A at 12V.
-Jim

Click to expand...

Originally posted by bobkrech
Make sure you have an ignition system that will supply 100 amps if you plan to use copperheads. That's the current that 5 copperheads will draw when fired in parallel. https://www.gwiz-partners.com/igniters.pdf

Click to expand...

The same file.