> If I took three "C" type engines, and somehow centered them in the bottom
of a rocket, and got them to all ignite at the same time, would the rocket
go higher than it would with just one C engine??? >>
You'd have a cluster. It's fun. People do it quite a lot. Yes, it will go
higher than one C engine. But in general, you use a cluster to loft a
heavier rocket to single-stage altitudes, and two stages to loft a small
rocket to higher altitude.
>>Would that be equal to a D or E engine??? What would it really do????
The "C" in C6-5 stands for a limit of 10 newton-seconds of total impulse --
the total power packed in the motor. Any motor with more than 5 and less
than 10 is a C, and the Estes C6 is reportedly 9 or so. You would add the
three 9's together for a total impulse of 27, equal to a medium E motor, and
very close to the total for the Estes E9.
Now then: the "6" in C6 is the (approximate) average thrust of the motor,
how hard it pushes. With a cluster, you also add those together, so three
C6's become an E18, meaning it has about the same total power as that E9 but
pushes twice as hard for half as long. That makes it best for a heavy
rocket (around 10-14 ounces, say). A cluster of 4 D12's becomes an F48: a
very serious output of power and a popular modification to the Estes Big
If you stage them, using C6-0, C6-0, C6-7 one after another, you still add
up the total impuse (9x3=27) but not the average thrust. In effect you now
have an "E6" that burns longer than an E9 but pushes only 2/3 as ***
average. The first motor would have a hard time lifting the whole rocket
off the pad, but if it once got going straight up, it would seem to go
forever. Using a D12-0 in the first stage will give you more thrust for a
stronger liftoff, and then a longer gentler thrust for extreme altitude.
This is the idea of the Estes Commanche-3.
Either way you've left your "little toys" behind and are flying some serious
rockets with perhaps the most commonly available, least regulated motors.
I once wrote a web page on clustering which is now found on InfoCentral. Go
to http//www.rocketryonline.com and click on the InfoCentral icon at the