# Stepper Motor for Fatigue Testing applications

Dear all,

I’m trying to build a table top fatigue testing machine using stepper motors and lead screw type actuators. My immediate task is to control the stepper motor to achieve varying deflection amplitude (Moving the actuator up and down at varying displacement amplitude). I’d like to know whether we can achieve this task using stepper motor. If YES, I’d look forward to having some suggestions as to how to control the frequency of the stepper motors to achieve varying amplitude up and down motion.

Kishore

Hello.

Your question is relatively broad and hard to answer with any specific suggestions. It sounds like your overall question is whether or not you can control your stepper motor-based linear actuator to move up and down with different stroke lengths, and I do not see any reason why you would not be able to. Do you have a particular stepper motor and driver/controller in mind? If so, you might find the information in the stepper motor’s datasheet helpful for getting a sense of its mechanical properties. To control the stepper motor how you want, you will likely need to write your own software for whichever driver/controller you use.

Brandon

Hello BrandonM,

Thank you. I’d like to post a specific question regarding the above mentioned generic statement. Lets say, I want to move 1 Kg mass up and down (from point A to point B of total 100 mm) in 1 second.
Mass orientation is vertical.
Lead Screw type = Diameter 8mm
Length between bearings = 200mm
POwer supply = 36V DC; ~5A

Can I be able to achieve this task by stepper motor?

Thanks and Regards

(Kishore)

It is not always trivial to say whether or not a particular stepper motor can handle certain conditions like that since there are many factors that go into the system’s capabilities. However, you can typically find a pull out torque curve (torque vs speed) at some specific settings (e.g. voltage, current, microstep) to give you some idea of what the motor can do. Ultimately, you will likely want to calculate the actual torque and speed you will need the motor to produce to get the desired behavior from your lead screw, then see if you can find a stepper motor that seems like it should be capable of that.

Brandon