[Lennyglyn]

Hi, not just needing help but newbie alert too.

I think I need to replace one or both of the steppers in my laser machine. It is Chinese built, runs on Lasercut 5.3. The motors have a label on them but try as I might I can't find out anything about them (see attachment). As much as I know is that they are NEMA 17, the bodies are about 38mm / 1.5" deep and they have four wires. The label reads 42-H250C13, and NO 1411 is on the second line followed by a lot of Chinese characters.

Does anyone recognise these and know where to get replacements? Or just know the full spec so I can find a like-for-like replacement, maybe better quality?

Many thanks!

[Jim Dawson]

This would be a good place to start. https://www.automationtechnologiesinc.com/

Are you sure the motor is bad? Stepper motors are about the last thing to fail in a system.

[Dean448]

I never had one fail and very unlikely two would go at the same time. Try swapping with another motor just to see if it’s the driver. Never unplug one of these with power on.


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[Lennyglyn]

Thanks, will take a look

[Lennyglyn]

I never had one fail and very unlikely two would go at the same time. Try swapping with another motor just to see if it’s the driver. Never unplug one of these with power on.


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The machine has recently started cutting round holes as skewed ovals and non-square square holes. This follows a heavy collision of the head, with lots of grinding noise until I managed to hit stop. I have to clamp some materials onto the table and try to keep out of the way of the clamp heaps, bvut on this occasion I screwed up. I have checked all the usual things to see if there is an external mechanical cause of what looks like a backlash issue, but nothing seems to improve it. Tried belts tighter, looser, made sure everything is lined up and lubricated, so the last thing is what I can't see - inside the stepper. I admit to ignorance on the subject of stepper motors, I have no idea if they have any toothed or geared parts inside, but the cutting results are indicative of some "slop" in the system that I can't find in the open parts of the drives.

[Jim Dawson]

There are no mechanical mating parts inside of a stepper motor. The coupling is all magnetic. They can ''grind'' away all day long and not be damaged. The noise is caused by the magnetic decoupling of the stator/rotor. It goes back to normal once power is removed.

Something else is the cause of your problem there. There is a very remote possibility that the press fit between the rotor and the shaft has come lose, but I have never seen this happen. If the stepper motor is connected to a gear box, then it is possible that the gearbox is damaged, but even this is not common. I'm not able to see exactly what the stepper is driving, but from your description I suspect it's just a pulley that drives the belt.

It is possible that the pulley is loose on the motor shaft.

[Lennyglyn]

There are no mechanical mating parts inside of a stepper motor. The coupling is all magnetic. They can ''grind'' away all day long and not be damaged. The noise is caused by the magnetic decoupling of the stator/rotor. It goes back to normal once power is removed.

Something else is the cause of your problem there. There is a very remote possibility that the press fit between the rotor and the shaft has come lose, but I have never seen this happen. If the stepper motor is connected to a gear box, then it is possible that the gearbox is damaged, but even this is not common. I'm not able to see exactly what the stepper is driving, but from your description I suspect it's just a pulley that drives the belt.

It is possible that the pulley is loose on the motor shaft.

Thanks Jim, that is very helpful. I will disassemble the drives today to see if I can find anything outside the motors.

[germanr]

If I understand the description of the problem, I recommend you to check the LaserCut configuration.
It can be a configuration issue of the steps of the motors and the size of the working area.
You should use the system.cfg file that comes with your machine.

Regards!

we are:

BuchiCNC USA

You can check our CO2 laser cutters here:
CO2 Laser cutting machines

If you want a metal laser engraver:
Laser metal engravers

Great CNC Router:
CNC Routers

[Lennyglyn]

- - - Updated - - -

If I understand the description of the problem, I recommend you to check the LaserCut configuration.
It can be a configuration issue of the steps of the motors and the size of the working area.
You should use the system.cfg file that comes with your machine.

Regards!

we are:

BuchiCNC USA

You can check our CO2 laser cutters here:
CO2 Laser cutting machines

If you want a metal laser engraver:
Laser metal engravers

Great CNC Router:
CNC Routers

Thank you, I will take a look at that.