Broken stepper motor - Too high of a load?

Question

I am using a NEMA 17 (17HD4005-22B) with a Big Easy Driver and an Arduino Uno R3. I am using the motor to move a threaded rod, which then pumps a liquid. The system basically functions as a linear actuator.

After trying to move a much too high load, I noticed that the stepper motor was not turning correctly. It moved erraticaly forwards and backwards a couple of steps. I also noticed to following:

• When I give it the signal to turn, I can turn the shaft very easily with my hand in either direction
• When it is powered and without any signal to turn, I can turn the shaft easily with my hand in either direction most of the time. If I crank the potentiometer all the way, I can not move it anymore
• I connected the motor to the stepper drivers of an i3-clone printer, and the motor does not turn. The previous two observations remained
• I connected the Big Easy Driver and Arduino to one the motors of the 3D-Printer and the 3d-printer motor did not turn
• Both windings of the broken motor have the same resistance

My doubts:

• Is it possible that the high load caused the stepper to break?

• Is it possible the driver is also broken?

• How can I check any these possibilities?

Answer 1

Motors fail from inadequate current controlled torque.

Your testing and results in your question must include;

• coil DCR of each motor, current setting / rating, max acceleration, max velocity threshold for slip errors

It unlikely you have a faulty motor and more likely excessive acceleration for the new load.

Answer 2

A quick Google on the part number reveals that your stepper motor is a four-wire stepper motor, rated for 2.4VDC and 1.3A. That works out to 1.8 ohms for the coil resistance, and your measurements are close to that. You don't say whether windings are shorted together, but I strongly doubt that they are.

My FIRST guess would be that your controller is not able to supply enough current to drive or hold the motor. In motion, or in hold, your controller must supply 2.6 amps (1.3A to each winding).

Stepper motors generally don't break if the applied mechanical load is too high. They just sit there, slipping steps and getting hot.

You don't mention a heat sink on your controller. My guess is that you've smoked your controller.

Answer 3

It's probably the motor controller. If the motor were to fail usually its from heat and it either seizes up or the winding's fail.

Check the windings with an ohm meter and make sure the winding's are continuous and low resistance (or check the datasheet if it has a winding resistance).

To check the driver, get a motor that you know works and use it with the driver. If the motor works, then it must be the driver. My bets are that the driver is broken.