Re: FW: Model Rocket Plan

On Sun, 2004-08-29 at 20:04, Rick Eversole wrote:
> On the other hand, using just one motor (nozzle) with movable deflection
> plates in the exhaust stream would seem much better:  The displacements
> could be calibrated with the motor off, and the relatively low temperatures,
> I think, would mean that the deflection plates would not have to be of
> special refractory material.  Of course, corrosive ablation might be an
> issue.

	If we go this kind of route, we can have BoJo make use deflectors out
of silicon carbide relatively cheap. Wire EDM is magical. With eight
deflectors, you can even get roll control this way. 

> I think just two solenoids would be enough, with feedback-determined
> deflection under flight-control system control.  Using feedback from an
> attitude reference system, based on a couple of gyroscopes or a solar or
> stellar image, might mean little or no need for calibration at all.

	That could end up being some sort of band-bang control system, but you
need at least four controller, since you need at least four paddles. 

	-p