# servo motor current

Status
Not open for further replies.

#### momin

##### New Member
hey everybody,
im using a servo motor for my FYP, the servo im using is Parallax standard servo motor. which is manufacured by Futaba. the motor is used to lift a small and light piece of wood (45 g, 10 cm) or (0.45 kg.cm). i wish to know how much current would this motor drain under 5 V. (while moving and while breaking)

Last edited:

#### dknguyen

##### Well-Known Member
FOr rotating motors, 45g is a meaningless information. It is the torque that matters so you need to know the weight and length of the lever arm that the weight is sitting at the end of.

THe maximum typical operating current of standard sized servos is usually between 1A or 2A. For your servo and the load you are trying to move 1A is probably more than enough. For what you are doing 1A Is probably more than enough. THe actual current is realy hard to measure because servo motors never work in steady state. Current measurements for servo motors are really erratic and unpredictable. YOu could do the same movement twice, and the current measurements would be different both times. When the servo is holding a load it's current also jumps around erratically.

You could also use the stall current of the motor inside the servo if you know it. THis would be the absolute worst case and the motor would be close to damage (if it hasn't damaged itself already). But the regular operating current is usually (and should be) much lower than this.

Last edited:

##### Banned
He didn't just give a weight dk, he gave the .45 kg/cm value, that is torque. He needs to find out what the Futaba servo model is to determine what the comparable load on the servo is going to be.

#### dknguyen

##### Well-Known Member
He didn't just give a weight dk, he gave the .45 kg/cm value, that is torque. He needs to find out what the Futaba servo model is to determine what the comparable load on the servo is going to be.
He originally worded it as "45g, 10cm" which I took to mean he needed to move 45g a distance of 10cm. He has since edited it to make it more clear that 10cm is the lever arm. 0.45kg/cm is well within the capability of any standard servo. I'd ballpark that 500mA would be the max. Definately under 1A.

The servo is most likely the Futaba S3001 Standard (the cheapest, weakest of all Futaba standard-size servos) which has a torque of 2.4kg/cm. It's torque is so low it's not much stronger (sometimes weaker) than even the smaller Futaba servos.

Last edited:
Status
Not open for further replies.