View Full Version : cluster BP and AP

13th September 2009, 04:38 AM
Anyone successfully cluster BP and AP motors?

My kid designed a rocket, he wants to use a central Aerotech E30 with a few C6's as sustainers. This will be launched on a club launcher 12V with some umph behind it. I was planing to use the new quest igniters for the C's and a first fire for the E.

Any thoughts?

13th September 2009, 04:40 AM
As long as you light the E motor, then don't light the Cs until the E is burning, you're fine.

You want the rocket light enough it's stable with just the E lit, in case something keeps the Cs from firing.


15th September 2009, 12:54 AM
<raises hand>

Yes I have, quite a few times. Here is what you want to do.

First off, get your rocket prepared for flight. Insert a good igniter in the composite motor(s), which should be the center motor. Now go and grab a Styrofoam soup bowl. Cover the bottom of the bowl with a layer of 4f black powder. If you talk to anyone at my club, they will tell you that more is better and that you should fill the bowl. While this isn't necessary, it does look pretty cool.:cool:

In reality, you should have a layer of BP a little less then a quarter of an inch thick. Now when you go out to the pad, insert the rocket onto the pad and place the bowl under the rocket, on the blast deflector. Use a bit of tape to secure it, and hook up your lead wires.

This is called a flash pan. You will see why when you do it. What happens is when the central motor is coming to life, it will spew enough flames out the motor to ignite the BP, which in turn ignites the Estes motors.

Two quick tips. One: clean out the nozzles on the Estes motors with a small screwdriver or piano wire.

Two: Find someone at your club to help you the first couple of times.

If you look up " kelfam48230 " into YouTube you will see my YouTube Chanel. In a few of my videos I show myself making flash pans. Take a look at those to get an idea of bow to do it. There are lots of people with lots of different methods, and this is just one of them. Take the advice of someone at you club who has done it before, and use common sense with BP.

Hope this helps.

15th September 2009, 06:01 PM
now that sounds cool!!

how close do you keep the flash pan to the end of the AP motor?

15th September 2009, 06:34 PM
now that sounds cool!!

how close do you keep the flash pan to the end of the AP motor?

What I do is trim the Styrofoam on the bowl until the ends of the motors are really close to the BP. It is really more of an art than a science.

It also gives more of that "WOW" factor. 3. 2. 1... THUMP! WOOSH!:eek:

Go to about 2:30 in this video.


Go to 3:30 in this video. (I found out it had a bad igniter in it the first few times.)


Let me know if this works out for you.