ok, a couple of items of importance here (It would be interesting to work up a class session for NARCON on this, frankly...)

When using canted motors here is what is happening:

- The off balance (sideways) thrust is canceled (assuming that the angle of the cant is the same and that they intersect a point that is in the *center* of the rocket. The way to calculate the motor power/impulse is to take the cosine of the cant angle times the thrust curve of the motor times the number of motors (also assuming all motors are the same which they had better be

)

Now, a couple of important points.

To fly straight, it is NOT necessary that the angle of the cant result in an intersection point at the CG or the CP. The intersection point can be anywhere along the length of the rocket (or even beyond) so long as it is centered along the axis of the rocket.

*IF* however you have a misfire of one of the motors, the model *could* go unstable *unless* the intersection point is at the CG (CP does not matter in this discussion, other than normal CP requirements for stability)

If you have the motors canted such that they intersect at the CG and one or more motors misfire, then the NOW angled thrust is pushing on the CG and the model will remain stable but will fly slightly sideways. There is also a risk of it getting hung up on the launch rod.

Also, due to the nature of solid rocket motors, it is NOT possible to keep this relationship constant during the entire burn because even if you start out with the intersection at the CG, the motors expend fuel (weight) as they burn and the CG moves during flight.

The best bet scenerio is to have the intersection point slightly above the CG so that as the motors burn, the CG moves up, *through* the intersection point. This can be calculated for one motor type and would work fairly well.

The Deuce intersection point is near the CG but not *at* the CG. Experience has shown that, on average, the Deuce's Wild! is stable on only one motor.

The Tres, due to the nature of the design, has an intersection point that is way below the CG and instability is a real possiblity with 1 or 2 motors not lighting (however, with only ONE motor burning, this model will be greatly under powered...)

Sorry to drone on for so long, but one more important point concerning the adaptation of a flying saucer...

No two motors are identical, no two motor tubes are mounted exactly the same, no two motors ignite at the exact same time, etc, etc, etc.... This results in a build up of cumulative error. The CLOSER these motors are to each other, the less the effect these errors have on the flight.

If, however, you have the motors separated by great distance (inches), you create a "moment arm" that results in a multiplication of these errors.

If you wanted to put canted motors in a saucer, this should work fine so long as the ;motors are as close to each other as possible. You will note in FlisKits designs, these motor tubes are so close to each other that they actually *touch* at the top.

Hope all this helps!

jim