Steps/ Revolution off?

I think I have an issue with Steps per revolution (not sure). My laser had been working perfectly for a very long time but now when I tell it to do a rectangle that is 1.5"x9", it comes out 5/8" short of the 9". What should I do to fix this issue? I have attached my Ruida 6445S controller read out for reference.
2-12-24.lbset (14.3 KB)

Before or after Newly installed Ruida Controller


These machines don’t change their own configuration. Unless you changed something or it has never worked, I’d suspect a hardware failure of some type…

Clarify what happened and when…

:smile_cat:

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Good morning Mr. Wilborn!!
I think you are the one that helped me get the new controller set up and running.
To give you an idea as to when this started happening, I noticed it at the last update of Lightburn (just a timeline, not and accusation). I was working on a jewelry box and was trying to cut a rectangle that was 1.5"x9". It cut perfect on the 1.5 but cut 5/8" short on the 9. No matter what I did it was always short. I verified the size requested in lightburn and that was correct but the cut was off, I have gone through a half sheet of plywood trying to get it right. I think I might feel better throwing the plywood out the window :slight_smile: . Due to the comment you made about the possible failure of the hardware, I am wondering if my steppers are going out (specifically the Y stepper).

These are digital, at least until you come off the end of the motors shaft…

If you have something off, what you see is usually some mathematical relationship to what it should be and what it is.

This appears to be off in the Y direction… yes? X size is ok?

If this is the case, the Y axes signal path needs to be followed. Here you have two axes, if one is misbehaving, then you generally can reference the working one for good values and also use it to help diagnose the issue with the non-functional axes. I say generally as there is no reason each axes must have the same motor/driver relationship… might have a larger motor with different steps for one of the axes. This is generally not the case and you can compare them.

I’d suggest

  1. check the motor drivers to ensure they do not have a fault… there are green/red leds on the motor drivers… If the red one is lit, you have a hardware failure… These are mine… I circled the leds on one of them. While you are there, compare both switch settings.

  1. swap the control signals from the Ruida → motor drivers… this effectively swaps out everything from the motor drivers on. If the problem follows the swap, it’s failing before the motor drivers and is probably the controller.

If you want to do step 2, then let me know and I’ll rough out a procedure you can follow… It’s simply swapping the control signal connectors… It will make a home operation fail in all likelihood. So homing in the controller should be turned off… anytime the Ruida is in a home cycle, then the esc key will abort the operation.

When you swap them, run the job and see if the error followed the axes swap…


Are you 100% sure that it did operate correctly when you setup the new controller?

Before changing anything make a copy of the Ruida configuration for when you forget what you did… this is normal for a human, so make a backup. Any switch setting that are changed, take a photo, at least.

Do you have a voltmeter and can you drive it?

Good luck

:smile_cat:

Yes it is the “Y” axis only. When I get home I will try step one and see if that might be the problem. I do have a volt meter as well.
One more quick question. Shouldn’t both stepper’s have the same step value? My X axis is one value and my Y axis is yet another.

Generally they have the same stepper motors and drivers, but it’s not required. If they needed to be the same there would be no need to differentiate between the two axes.

If you’ve confirmed it’s only on that axes, it won’t really hurt it to change the stepper switches… there are only 4 for steps the others are for different options… Also, write down what they are before you change them. Are they all the same type, motor and driver?

Which switch(s) are different? Before you change it, figure out what is different.

If this switch is changed, it had to be by something living… or it wasn’t set correctly to begin with.

:smile_cat:

The Motors and drivers are, in fact, the same. I will check when I get home on the switches and get back with you.

Is it possible the Enable Rotary switch in the Laser window is (inadvertently) turned on?

Thank you for your response. It may in fact be possible!! I will check that too!!

Rotary is not enabled.

Ok, I matched the steps in the controller with the “X” axis and it is much better. It is only 1/8" off. If I add 1/8" to the rectangle, I get the exact size I need (very puzzling to me).
I checked the lights on the driver and they are both green. I also checked the switches on both drivers and they are the exact same.