The theoritical static torque required was around 27 kg-cm. For the first time when we tested,the servo was able to draw the rated current of about 5.1 A at 7.4 v and was hence able to lift the arm. But,after that it never happened again and now it is able to draw only a max of 3-3.5 A. We replaced the servo with a new one of the same type,but even that new one is unable to draw the required current. We tried changing the power source,we tried increasing the trace width of the shield we made to connect the servo with arduino and power source, we replaced all the wires with thicker ones and tried almost all possible solutions…
Any suggestion regarding this will be deeply acknowledged.
As you indicated, the theoretical maximum torque that servo can provide is 30Kg-cm. Note that the servo has a duty cycle of about 25%, and maintaining that torque for an extended period of time will ultimately burn it. At 27Kg-cm, you are very close to the maximum value. Can the controller you are using handle the required current? It sounds like your controller may have been affected. Do you have other servos also drawing current at the same time?