dasintex

My Feedback: (10)

Will using a longer Servo Arm decrease the amount of Torque that a Servo can put out?

exeter_acres

My Feedback: (2)

IIRC it will decrease the torque,
but it will increase the throw or angle of deflection of the surface

dasintex

My Feedback: (10)

Does it decrease the amount a lot or very little to be of any notice.

pettit

My Feedback: (23)

If you have a 100 oz-in servo with a servo arm that is 1" long. It will lift a 100 oz. weight.

If you move the connection from 1" to 1/2" from center of the servo shaft, you can lift a 200 oz. weight.

But it will move 1/2 the distance

dirtybird

My Feedback: (5)

Torque is force times arm length. So no matter what the arm length is the torque produced is the same.
The force the servo produces will change inversly with the arm length.

dasintex

My Feedback: (10)

So to get it straight; the longer the arm is from center the less torque; in the example given: 100 oz would have 100oz at 1", 200oz at 1/2"; therefore at say 2" the torque would be 50oz; right?

LesUyeda

Almost. Your numbers are correct, but torque is a constant. The variable is the "force" at the end of the arm. The numbers you cite, are force.

Les

dasintex

My Feedback: (10)

Got it now; tell me, when Servos are rated for their Torque is that assuming a 1 Inch servo arm or 1 inch from from center to arm end?

huggins

Servo torque is a function of the motor itself and has nothing at all to do with the length of the arm. I think some of the confusion is that torque is always expressed wtih units of "force X length", which in servos is oz-in (ounce-inches). Modelers commonly (an eroneously, I might add) shorten it by just saying "ounces". There is no such thing as a 100 oz. servo. Properly stated, it is a 100 oz-in servo. The length of the arm effects the throw and the force available at that length. Longer arms equals more throw but less force, while a shorter arm yeilds less throw with more force. If you want to know the force available, divide the torque (oz-in) of the servo by the arm length (in inches, from center of shaft).

Mike

Bob Pastorello

My Feedback: (198)

Since we're really asking about "how easy or hard to move a control surface"... the answer is....Longer servo arm makes it harder to move a given-size control surface in it's intended performance regime. Shorter arm will move it LESS, but more easily.