Experiences with Estes C11-0

[saxophone]

I build a lot of scratch built multi-stage
rockets, and I also modify existing kits.
For example, I've scratch built several
3 stage rockets, usually with 24mm mounts
in the bottom stage. I've also modified
a Quest Navaho to become a 3-stage rocket
with a 24mm mount in the bottom stage. All
of my multi-stage rockets use gap staging.
That is, there is gap between the two
motor mounts, and vent holes are drilled into
the sides to prevent premature staging before
the upper stage is lit.

I've had no trouble with the D12-0. However,
I've had 2 staging failures involving C11-0s.
Putting the C11-0 in the bottom stage has
failed to ignite the stage above it in 2 out
of 3 cases. Is this just bad luck, or is
there something in the C11-0 that makes it
less likely to ignite the next stage? Does
the C11-0 burn to fast not allowing for enough
hot particles to be thrown up to ignite the next
stage? Is the C11-0 propellant too far down
the motor casing for the hot particles to reach?

Has anyone else noticed a difference in staging
performance between a C11-0 and a D12-0?

Thanks.

 

[KenParker]

I have an Estes LongShot which I modified to be a 3 stager, and further modified to make the main stage a 24mm motor mount, so that all three stages were 24mm powered.

I had pretty good success flying it as a 2 stager with the regular gap staging using D12-0 to D12-7. This combo ignited the upper stage about 4 times out of 5.

I tried THREE times to get it to stage using C11-0 to C11-5. It NEVER did light the upper stage.

I finally butchered - er, excuse me - "adjusted" the length of the boosters so that I could tape the engines together. They staged fine this way. I have successfully flown it twice as a 3 stager with the enigines taped together in a C11-0 to C11-0 to C11-5 format. It is really cool flying it with this combo, as I can still recover the boosters, and the main stage still gets pretty good altitude, and I can still see the main stage to track and recover it, too.

I have read that some people have been successful with gap staging with as much as a foot between the engines (although I don't recall what engines they used - but I'm pretty sure it wasn't C11-0s). It is amazing to me that it worked.

I have no idea why C11-0s don't like to gap stage. They do have a very short burn, so maybe your idea about them not having enough burning particles to fly forward and light the other stage is accurate.

Anyway, that's my story on C11-0s and gap staging.

- Ken

 

[n3tjm]

How much space is there between the C11-0 and the motor in the sustainer?

 

[saxophone]

I think the gap I am using is about 1" or less.