Force required to change Thrust vector

[iskeat]

Hi everyone, im looking for the equation to calculate how much force is required to change the vector of thrust.

Experience:
None, i am not an engineering student and have 0 experience with real world application. I just love building.

Project:
Thrust Vector Controller on a model rocket

Problem:
I am trying to use the smallest servos possible to control the thrust vector. Ive used tiny ones (9g) and the motor slammed to one side, completely overpowering the servo. Now im using large (25 kg) RC servos and they and just massive and heavy, but they work perfectly. I would like to be able to calculate the exact force needed so that i can choose a smaller servo if possible.

there is a crappy hand drawn diagram attached for your reference

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Sorry if this is the wrong forum for this post

 

[iskeat]

 

[3DDave]

If the thrust is through the pivot then the only force required is to overcome friction.

I can't tell what your attachment is - here's one that isolates the thrust load from the servo:

https://www.youtube.com/watch?v=gU74BF0-DcA

Here's a talk by a guy who has done this successfully:

https://www.youtube.com/watch?v=4cw9K9yuIyU

 

[iskeat]

Thanks 3DDave

Ive watched those and my setup is pretty similar. For whatever reason those exact servos were not able to handle a F motor.
Maybe i should give that setup another try.

 

[3DDave]

Which "F" motor - that gives a range for the total impulse, not the maximum thrust.