# How to calculate the dependency of speed and weight of a servo? [closed]

Here is a digital servo: Servo

By using the information of details of that thing what is the way to calculate the dependency of the speed of the movement of the car if the load upon the servo is N kg (or gram)? For example I need to know what maximum weight that servo can handle with a maximum speed of M m/s.

-
If the motor has a constant power, you have the the relatively easy formula $v=P/F$ –  Manishearth Mar 30 '12 at 6:15
It would be better if you researched the specs and listed them here first. Without knowing what is constant, we can't answer the question. –  Manishearth Mar 30 '12 at 11:25

## closed as not a real question by Qmechanic♦, Manishearth♦, dmckee♦Oct 12 '12 at 15:13

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

There is no way to calculate this from the given information.

For an estimate you need the rpm <-> torque curve of the builtin electric motor. This is usually only taken at a constant rpm, so I does not tell you much about the inertia from the rotating pieces, such as the gears, in the servo.

Additionally a 'digital' servo implies some kind of control loop to accelerate and decelerate the motor, which will be non-linear.

In many cases the speed of these servos does not depend too much on the load until you reach a certain threshold. So you can assume that the given speed of 0.17sec / 60 degrees does not change too much under light load but will drastically go down when you approach the maximum torque of 13 kg cm.

If timing is crucial for your application why not test the load/speed relationship yourself?

-
Thanks for a reply! :) –  maximus Apr 1 '12 at 16:21