Asked
— Edited
Resolved by DJ Sures!
I have a couple of servo's that do not move freely when the power is off. Is this normal? They do move when they have power and control them via ARC though. Should I be concerned? *confused*
Servos have gears inside that convert speed into torque. The gearing gives a tiny motor a bunch of torque to lift heavier objects. A motor alone will not have the strength to move gears.
Because the gears convert the tiny motor speed into output torque, there is a reverse process when applying energy to the output shaft. For example, when you apply energy to the output shaft - you are actually reversing the process. What you are doing is spinning the motor very very fast - but using much more force to make it happen.
The output shaft on a high torque servo may not always move freely.
Here is a great explanation on how gears work: http://science.howstuffworks.com/transport/engines-equipment/gear-ratio.htm
We have many robots where the gears do not move unless they are powered and moving by the ez-b and software.