Clustering question

I know I'm going to get pounded on this one. Well, maybe not... I've searched everywhere I know to search. There are tons of posts about clustering, comments on websites about clustering, etc. But I have yet to see any designs of the wiring harness for clustering. I'm sure there was an article or two that I missed. Can anyone point me in the right direction?

I offer to sacrifice one of my rockets to the rocket gods in the name of the person with the best link.

As my two flights on the 26th indicate, if I had a link, I didn't read it carefully enough

But, you can find an article on clustering BP motors, written by our own micromister (aka mrcluster) here Go to tech libray/tech tips.

what is the difference between making a single engine and clustering the theory remains the same but you just have 2 or 3 motor in it so you have three shoots on the piston or what ever your recovery system or you could take out the ehection charge in two of them and have one of the engine eject the parachute

The issue with clustering is reliably igniting all the motors. I suspect Phil is interested in starting multiple HPR motors.

Matt, I have a central 54mm and 6 outboard 38mm. I want to launch with the 54mm. And then airstart the 6 outboards. That is the standard clustering idea. That is launch with one and airstart the others. Timers are used to do the airstarts. So, what I'm looking for is schematics of how to hook the matches to the timers and to the outboards, etc.

Dick, that link was good but he is only talking about BP motors. There has to be links that talk about timers and such.

Phil, yeah, I knew what your were up to having seen the new rings last weekend But it's the only link I had.

A lot of what uou are asking depends on where the timers (or other electronics )are physically, relative to the motors. Wire routing is an issue.

You know, Phil, a real man, a real *L3* man, would liftoff on the 54mm, then airstart *three* of the 38mm's, then airstart the remaining three 38mm's....... now *that* would be cool.

here's a site for ya from the Gates Bros site

Well I don't know if this will help Phil; but check out this page at Rocket Team Vataas:

www.vatsaas.org/rtv/lessons/clusters.aspx


I love cluster rockets; but I've never air started one before. The three things that I can think of is:

#1. make sure your electronics can provide enough power to fire all of your low current ignitors
#2. I've heard it recommended that your electronics should be powered by a seperate battery, to prevent failure caused by a sudden voltage drop from the ignitors
#3.

Make sure you don't have any loose connections!
Remember: loose wires can burn down houses! Not to mention cause one or more motors not to fire.

I hope this helped a little.

Hey Phil,

I think I hit on some of this the other day in the "nutshell" version and you'll be able to see the pics coming soon, but yes the 3 and 3 idea is superb

Another nutshell: I had a board in the fin can that ran a long wire out to the motors via conduit. I then wired my matches in parallel integrating the wire leading back to the timer and GWiz.

Here's a few of checklist nuggets:

1. test your timers to make sure they will fire 3 at a time
2. Dip your matches in pyrogen covering the head and at least an 1" down the wire (Dick calls this cheating, but I like to put some t-lite on there too)
3. Make your checklist now or I can forward mine to you if you'd like
4. Make sure that puppy has a hot 54 to get it safely off the pad regardless of hitting the outboards
5. Sim it out with just the outboard motor weight as a mass object to see what will happen if they don't hit

Clusterstruck has psyched me big time on air starting thus my L3 will be made to do so....after the qualifying flight of course.

Look out second mortgage!


Shane