4-Fin Fat Boy Cluster

[Elapid]

I can send this up on any 18mm pair of motors or a 24mm pair, or 4 - 18mm, or any combination!

i have an extension tube 28" long to use in case i want to put in a lot of motors, but keep the altitude lower...i haven't sim'd it yet. i suspect some nose weight may be in order if it's fully loaded up

 

[Karl]

Very nice! That things gonna' rock! Dare you fly it on all the motors it can take ? ;-)
-Karl

 

[Elapid]

Originally posted by Karl
Very nice! That things gonna' rock! Dare you fly it on all the motors it can take ? ;-)
-Karl

i think i'll need a bigger field!

 

[wyldbill]

Don't forget to plug the MMTs you're not using...

 

[Elapid]

I have the 13mm holes plugged at the forward end.
the rest will have plugged casings to ensure that the deployment system operates properly.

i think i'll make some extra clips for the launch controller too!

 

[Elapid]

i made some nifty plugs from old motor casings plugged with wadding soaked in thin ca glue

i painted them red so they will be easy to find in my cluttered range box!

 

[rstaff3]

Very nice...2 A10s, 6 C6s and 2 E9s...and lotsa nose weight

 

[Elapid]

but i want to keep it under a pound rtf
swing-testing is in order before a fully loaded launch.

there are only 4 - 18mm mounts though...

 

[powderburner]

Dump the plugged motor casings.

Take a slot out of the side of some BT and make your own reduced-diameter tubing to slip into those holes, and cover/plug the ends with some foamcore disks. That will be MUCH lighter and will not require adding nose ballast.

Or if that is too much work, order some tube-coupler stock from Totally Tubular. I think he carries it in three-foot lengths, and you can cut lengths that are equivalent to the motor casings.

 

[Elapid]

2x E9-6
2x A34T (looked fuller/heavier than the A10 motors)
4x C6-5
recovery system

and no fakies installed.

dry weight is 187.1g
the motors weigh 242.3g

total weight= 429.4g

the fake motor casings weigh almost nothing and are for flying the rocket on any symmetric arrangement of motors, i.e. 2 - C6-5 and the rest plugs. or 4 - C6-5 and the rest plugged, etc.

the plugs weigh 7.9g and 10.6g for the 18mm and 24mm respectively.

 

[MetMan]

Originally posted by powderburner
Dump the plugged motor casings.

Take a slot out of the side of some BT...

Another option is to use those yellow "dummy" engine tubes as "fakies". Fill one end with tissues soaked in wood glue. What else can you do with those things?????

MetMan

 

[bsexton]

What are you using for motor retention - friction fit?

 

[Elapid]

Friction fit.

it worked 30 years ago, and still works today