Clustering BP in the post Q2G2 era

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J Blatz

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Man, the Q2G2 was great. I have a few left but want to keep them for certain special applications.

I recently prepped out a 3 X D12 cluster using this technique - turn D12 upside down, pour a small amount of BP in the nozzle, filling it to within 1/8" of the end of the exit cone. Then I "inserted" a flashbulb (with pre-wired leads) against the end of the motor, and used a single wrap of 1.5" wide masking tape to scrunch to whole thing together. The leads of the flashbulb are shunted, of course, at all times.

When I go to fly it, I will make sure and spot-tie the flashbulb leads to the launch rail to make sure they pull off and don't try to take the alligator clips and launch controller cable with them, leading to a dangerous off-vertical flight.

Another thought I am entertaining for BP clustering is the use of the non-regulated Firewire "lighters". They have small heads and probably would be fine for D12's, etc. Thoughts on this?
 

Crazyrocket

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I have used the Rocketflite igniters (clusterfire) that works really well. Lit 7 BP cluster with no problems. You may want to look them up.
 

TangoJuliet

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I'm interested in knowing what the preferred method(s) is/are for clustering BP motors and getting the most reliable results. I'll need it for launching my Ventris SRB when it's done.

Are flashbulbs still available? I know back 25-35 years ago using flashbulbs and flash pans were what most of the more experienced rocketeers were doing for clustering, but I never had any experience with it. I was just a teen back then.
 

Rocketjunkie

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I have used Estes igniters in the past. Add extension wires to the igniters, either soldered or wire wrapped. Check the nozzles of all the motors to be sure there is no clay over the BP. If the BP at the bottom of the nozzle isn't clear, use a drill bit to remove any clay. Add a small amount of BP to each nozzle and install the igniters the usual way with the plugs. Carefully make sure no igniters are shorting with another, insulate with tape as necessary. Measure the resistance of each igniter - replace any that show high or zero resistance. Twist together into a group one wire from each igniter, then twist the other wire from each igniter into a second group. If you use long extension wires, you will give more time for slower igniters to fire before the igniter cluster is pulled from any unlit motors.

However, I cheat - I still have plenty of Q2G2's :smile:
 

cwbullet

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You can use Chinese made ematches or the new blue and white ones.
 

jimzcatz

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As Chuck said, ematches if they fit in the noozle. I use the BP, flashbulb method with 100% success. I have never used a Q2G2.
 

BDB

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How about Estes Sonic igniters? I've heard folks around here who don't like them, but they've always worked for me. And their long leads should make clustering easy.
 
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