L2 test question-pool - clustering BP and AP

bit eimer wrote:

(not
of
point of

motors
I've done it lots of times. Sometimes in a traditional cluster rocket, sometimes with the BP motors in strap-on boosters while using a composite motor for primary thrust.

It's fun! :)

launch
Usually, the BP motors are air-started. This can be accomplished either with fuse such as Thermalite, or with a timer or other electronic device.

With the above methods, the ignition delay is controlled and can be anywhere from "at first motion" to several seconds after liftoff.

the L2

Clustering BP and composite motors isn't all that unusual, and expecting both types to light at the same time is a fairly common mistake.
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Of course there's the option I use to use when I was younger (much). Ignite using 120V AC. Almost instantaneous ignition on just about anything. But you probably don't want to use a stock launch system.
Don't try this at home, kids.
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My 4" dia. upscaled Der Red Max has a 2x24mm + 1x29mm and has boosted successfully on (2)E9-Ps and (1)G80-7T in the central mount. It flew twice with that configuration and both times I had instant ignition with all 3 motors igniting successfully.
"If" you are attempting a cluster of AP/BP and aren't planning on airstarting the BP, I would *only* use a Blue Thunder or other quick-to-ignite AP formula.
Unfortunately the G80's casing had a burn-through on its final flight which negated any ejection. :(
Here are some pictures of the boost courtesy of Mr. Karl Simpson and Ray of TRF:
Just after ignition -
http://www.hercrocketry.org/img/misc/der_red_max_liftoff.jpg
Midflight with nice Blue Thunder flame -
http://www.hercrocketry.org/img/misc/der_red_max_boost2.jpg
bit eimer wrote:

launch
the L2

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Surely if you can fit 2x24mm you could fit at least 4x24mm (in addition to the central MMT)- its a 4" tube, you could cluster 29mm motors in that! Anything like a single 29mm MMT in a 4" tube just seems silly to me :)
Nice photos BTW :)
--
Niall Oswald
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