The formula for finding the steps per mm is found in the units itself. First, you mentioned that the motor is a servo. This needs to be clarified as a servo is different than a stepper motor. Some servos behave similar to a stepper motor, so I will continue with this in mind.
The formula is (steps/mm):
You need to find the steps. The stepper motor has a natural number of steps per a full revolution. This is typically 200 steps per revolution.
The driver for the stepper motor allows you to increase the number of steps per revolution by adding a specified number of steps between each step. For instance, if you set the driver to 1/4 microstepping, then instead of having 200 steps per revolution, you would have 200 x 4 = 800 steps per revolution.
So now we have the first part of the formula:
Steps / mm = (200 x 4) / mm
Lets determine the mm side of the formula:
You mention that the pitch is 0.5 mm. Check to insure that the lead is also 0.5 mm. This could be a multiple start lead screw where the pitch is different than the turns per mm. If in this case, that the 0.5 mm is the travel for one full revolution, then you can simply plug this into the formula as:
mm = .5 mm
Otherwise, determine how fat the travel is for one complete revolution.
Therefor, with what we know and the driver is set at 1/4 microstepping and the stepper motor has a natural step count per revolution at 200:
steps / mm = (200 steps x 4) / 0.5 mm = 800 steps / 0.5 mm = 1600 steps / mm
If your travel for one revolution is not 0.5 mm, then plug in your travel distance instead.
i know about steps/mm calculation for stepper motor, because i am using servo motor that why i asked about that. please tell for servo motor.
because its my first time with servo motor i have no idea about calculation of parameter with servo.
Have you attempted to contact the manufacturer or seller of the servo? We typically respond to customers of our products on this customer service area, unless we have extensive knowledge of the subject and can answer the question efficiently.
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hello there, i am using servo motor for my X and Y Axis but i dont know how to calculate steps/mm for that, the lead screw i am using is have pitch of .5 mm. please helpme on this i have done everything only this point is pending.