Thrust Vector Control

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Maybe the centering isn't as big a deal since it obviously is using sensing to know what is up, so if there is slop it will still try to steer to correct
That was my thought too.

If you want to improve your chances of success when using different servos go for something quicker rather than slower (keep the transport delay in the control loop down) and try to minimise backlash, to similarly reduce any inclination to overshoot due to delayed response. I don't have a feel for how much margin they have in their control loop designs.

If you compare digital and analog servos performance, assuming the same parameters in their control loops, I am not sure anyone would notice the difference.
 
I'd have to look through the servos, it looks like it is built to take those specific servo cases so not sure what would retrofit. Maybe the centering isn't as big a deal since it obviously is using sensing to know what is up, so if there is slop it will still try to steer to correct...but I'd like to see a metal gear maybe digital servo. The niceness of this is for gentle long burn motors where you get a lot of steering, a high thrust two second burn only steers for two seconds, then its sort of tumble or whatever the stability margin of your finless design gets you,

I like the idea behind this kit. If the owner had responded to my questions, I would have put down the deposit on this thing, despite the limitations. However pricey and limited in utilization it may be, it would have made a fun demo rocket for the cub scouts.

The principal limitation of this kit is the one stated above - it only fits mid/low-power long burn motors. After the motor burns out, the gizmo is just ballast, and if the rocket is not aerodynamically stable, it weather cocks and/or tumbles each whichever way.

I can think of only 5-6 glider or plugged motors that could be a good fit for this type of a rocket (note - you have to build rockets for the gizmo, not the other way around). Just like gliders, this rocket could have its own niche place in my fleet.


plus the gimbal is held in by just four screws into a bt-80 type tube so not super sturdy for higher thrust. Maybe someone who has one or is building one will chime in.

The entire plastic sleeve for the gizmo screams "keep the thrust low and steady".
4 screw attachment points between the motor mount and the paper airframe emphasize the structural fragility.
The computer centering rings and ejection bulkhead are attached more firmly than the motor mount!!!
:dark:

The build video also fore-warns against having the motor mount tube take hits upon landing - it is not sturdy enough to survive an impact. Thus the instructions call for hiding/protecting the aft end of the motor inside the airframe!


I have one and will be building one :)

Always good to support your buddy - tell us how it goes!


a
 
The principal limitation of this kit is the one stated above - it only fits mid/low-power long burn motors. After the motor burns out, the gizmo is just ballast, and if the rocket is not aerodynamically stable, it weather cocks and/or tumbles each whichever way.

The entire plastic sleeve for the gizmo screams "keep the thrust low and steady".
4 screw attachment points between the motor mount and the paper airframe emphasize the structural fragility.
The computer centering rings and ejection bulkhead are attached more firmly than the motor mount!!!
:dark:

The build video also fore-warns against having the motor mount tube take hits upon landing - it is not sturdy enough to survive an impact. Thus the instructions call for hiding/protecting the aft end of the motor inside the airframe!

I see a lot of G33s in this system's future. :)
 
So..... has anyone actually bought and built this thing?
Care to share the findings?

I still have plenty of questions and reservations. One too many to throw $300 into someone's PayPal account.
The Qs were directed to the SA proprietor, but he never responded.

Alternatively, if someone on this forum has BTDT, that would be an even more useful source of feedback than the seller.
:confused2:

a
 
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