I have a Tower Pro 9g Micro Servo (SG90) and it's datasheet says it's stall torque is (at 4.8 volts = 25 to 16.7 oz/in or 1.8-1.2 kg/cm depending on the website), but as I haven't learned physics, I don't know how to calculate how much weight it can handle stacked on top of the arm/horn. I have googled torque calculations and the servo itself, but can't seem to find an answer to my question.
Thank you for any help you can provide me, I appreciate your time.
Torque is force times (perpendicular distance to axis of rotation). If you attach a string to the arm of the servo while the arm is horizontal, 1 inch from the axis of rotation, then 25 oz-in means that the servo could lift a 25 ounce weight with the string. Or, 12.5 ounces if the string is 2 inches from the axis of rotation, etc.
Always allow a healthy margin of safety, perhaps x2, to allow for friction and marketing
hype (torques quoted are usually stall-torque, not working torque).
Torque units are force x distance, NOT force / distance. This a common error in datasheets
and websites that confuses a lot of people.
What do you mean "x2"? Times two, what? Thank you.
Mark means that you should divide the advertized value for the maximum torque by two, to be safe.
Oh right, duh, thanks guys for pointing out what was right in front of me the whole time XD