I have a number of 3D printers each of which contain 4 Stepper Motors. All printers are malfunctioning and I am currently going through a process of diagnostics to try to isolate the problem(s).
One area I need some help is in determining if the Stepper Motors are actually working properly.
Perhaps someone who is familiar with stepper motors could tell me if simply testing the resistance of the internal coil windings is sufficient? Perhaps no additional testing needs to be done if the resistance of the coil windings are within manufacturers specifications?
I realize that each Stepper Motor is driven by a small DRV8825 / A4988 Stepper Driver Board. so it's possible that the driver boards could be faulting.
Finally, there is the Mainboard itself. Each Printer has it's on mainboard which could also be faulting.
But for now, I'm just asking what would be the best way to test the Stepper Motors (And Driver Boards).
Is there and Arduino Project that I can follow that will test my Driver Boards and Stepper Motors?
This Simple Stepper Code should be suitable. You will need to identify which Arduino pin is used for step and direction for the different motors.
Be VERY CAREFUL never to disconnect the wires between the motor and the stepper driver while the driver is powered up. The driver will be instantly destroyed,
Thank you for the reply. I have read ALL the information linked and found it very helpful.
I have several 3D printers and they are all giving me headaches after about 3,000 - 4,000 hours of use.
I am specifically wondering if it's "likely" that the stepper driver boards themselves could be causing issues?
Do stepper driver boards have limits to how long they can effectively control the stepper motors?
Do they "wear out" or lose precision over time?
quamikazee:
I am specifically wondering if it's "likely" that the stepper driver boards themselves could be causing issues?
Do stepper driver boards have limits to how long they can effectively control the stepper motors?
Do they "wear out" or lose precision over time?
I have no idea but my guess is that wear and tear is more likely in the mechanical parts - stretched belts and worn bearings. And that could include motor bearings which might affect the relationship between the rotor and the coils.
I would be surprised if any of the electronics fails in such a way that the problem is intermittent or results in reduced precision
unless there is a loose connection somewhere - but that is more of a mechanical problem than an electronic problem.
I concur. I would suspect stretched belts and sticking sliding bearings first. Brass bushing bearings are billed as "permanently lubricated", but that is marketing.
A stretched belt can cause the teeth to not quite line up with the teeth on the pulley, causing subtle patterns in the printed parts.
What exactly is the symptom of the failing prints? If all of your printers are going at once, I doubt they each have the same issue with Steppers. My 1 year old Prusa recently had fail after fail and after replacing belts, bearings and nozzles, works like new.
I tested the wires to all the extruders and heaters on one of my printers and found a problem shown in the illustration below.
Further examination revealed an internal break in the wire going to the Y axis. With a VOM attached at both ends, a little movement of the wire at a certain spot resulted in wild fluctuations in the resistance of the wire. I replaced the wire.
This resulted in one perfect print...but the next print failed again, however, the "new" failure seems completely related to the Z Axis as the X and Y axis seem to be printing properly. Or it could be an over extrusion problem as well.
I have no idea how or why the printer would have completed the first 6.5 hour print 100% successfully, then failed a second print.
After I post this, I'm going to go back and recheck the wires to the Z axis motor.
I believe I can rule out belts and bearings due to the fact that the first print was perfect and it was a 6 hour print.
