We have built a robot arm out of servo erector set parts. We are using HSR-5995TG servos for the base, shoulder, elbow, and hand joints, and HS-5475HB servos for the fingers joints of a two-finger hand. (The servos are all digital.) We are using an SSC-32 controller. My question is this: is it possible to get the servos to relax, i.e. to stop servoing? (We would like them to stop servoing without changing their current position but relax so that they will move if external torque is applied.) There is no documented SSC-32 command to do so. But is it in principle possible to get digital servos to stop servoing by reflashing the SSC-32 with augmented firmware? Can Hitec digital servos do so? Can digital servos from other vendors do so? Can analog servos do so?
We have considered using external circuitry to gate the servo power supply inputs to the SSC-32 (i.e. VS1 and VS2, leaving power applied to VL). Is there a better way?
The reason that we want to do this is that keeping the servos powered up and actively servoing under the load of the arm makes noise, vibrates, heats up the servos, and generally seems like something to be avoided. So we want to make our robot be able to park and relax for the (long) intervals between (short) active tasks.