Two synchronous servos
June 19, 2011
I am building a standar antropomorph robot arm and have come across a little problem. The arm is going to be quite big and heavy, so I ned a lot of torque at all the joints. So, my plan was to use two servos for the main joint. They would be working synchronous (both rotating the same part of the arm). I am also using external gears, so I also have to use externa potentiometer to controll the servos (I hope that you understand what I am trying to say...). And here is the problem, I have to controll both servos with one potentiometer. Potentiometer is used as a voltage devider. Using one normal potentiometer connected to both servos doesnt work(the voltage doubles). I have tried using a stereo potentiometer (two "pin sets" on one single rotating unit), but it also does not work, when one servo is still the other one rotates very slowly, I am guessing because the voltage deviders on the potentiometer aren't identical (not completly linear).
Any ideas how to make this work, my only idea is to make a circuit that would use the voltage that the servo controller sends to the servo motor as input voltage and would produce two identicall voltages as output for each servo motor, but I dont have a clue on how to do that. Or would a simpler idea work, just amplifying (x2) the output voltage of the servo controller and plugging both of the servo motors on one controller?
Hope you understood what my problem is, thanks for all your answers in advance...