Ye Olde Rocket Forum - converting single engine to cluster engine.

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- - converting single engine to cluster engine. (http://www.oldrocketforum.com/showthread.php?t=18021)

Quote:

Originally Posted by ghrocketman

Good luck flying a Semroc Brighton on a single 24mm anything short of an RMS24 F24 reload.

The F39 Blue Thunder in the 24/40 RMS is another good choice. I’ve also got the 24/60 RMS and there are a several high thrust F reloads for it, in a variety of propellant formulations.

Agree with the F39 and 24/60 statement.
Just don't go trying to fly it on any Estes 24mm LOW thrust BP motors.

Quote:

Originally Posted by metlfreak

I was thinking about building an Aerotch Initiator but instead of using the 29mm motor mount I want to use a 18mm 4x cluster motor mount and use 4 Q-jet engines which I think would be pretty neat. My question is though would I need to add weight to the nose for this or would it be stable enough without? The rocket can hold up to a G motor without mods and is pretty heavy built standard.

Ideally, to keep the fin-lok units, a 4 engine cluster, one central 24/29, with 18mm mounts between the 3 fins would be great. A quick calculation shows this probably wouldn't work - CRs are 2.558" with a 1.210" hole, leaving just 17mm. So the central tube would need to be 24mm, and fin-lok units couldn't be used. Still, though, the fins could be nestled between the 18mm tubes, making for a fairly solid attachment with some creative assembly.

An easier route would be 3x24mm, ASP makes plywood cluster centering rings that should fit. That gives you options from 3xC11 to 3xE12, or even 3xE28/E30. The fins should nestle between the 24mm tubes, with some trimming.

The four fins nestled between motor tubes is how I did my upscale Astron Cobra. I poured epoxy into the valleys between two fins, and attached one fin at a time until epoxied cured, then I added the next.

These are 24mm motor tubes in a BT-80H heavy wall tube.