Can I change "native world view"of a Ruida controller?

I’ve used RabbitUSA lasers for a long time, and I’m now upgrading an older Kern laser, using a Ruida 6445 controller, with the end goal to facilitate use of LB.

I’ve made a lot of progress, but I’m puzzled about something. It seems that the foundational “world-view” of the Ruida controller that X axis home position ( and corresponding limit switch) is at the rear RIGHT corner of the bed. That seems to be how the Rabbits are set up. For a lot of reasons, it’s best on this Kern if the home limit switch is at the LEFT rear corner. How can I set that up most easily?

I know that I can flip a lot of things by flipping coil polarity, and exchanging end-stop input positions, but i’d like to keep things simple if possible. Am I overlooking some oddly-named parameter in the machine setup dialogs?

Do you mean you have set the home in Lightburn to left back and it still homes to right back?

HI, @Enno.

No, not in Lightburn, but down at a lower level, within Ruida-land itself. The things that happen when I turn on the machine, or press the RESET button on the keypad. Put another way, it’s the underlying low-level reality to which Lightburn must conform to, by us telling LB where X0Y0 is.

Perhaps this document may help? Configuring a Ruida - LightBurn Software Documentation

Specifically, this section:

Homing, Directions, and Travel

A DSP laser will have homing switches - one on each axis. They might be physical lever-type micro switches, optical beam-break switches, or inductive proximity sensors. Locate the switch at the end of the X axis, and the one for the Y axis.

When you power up the laser, the first thing it will do is move toward the corner it thinks those switches are at to home itself. If it’s moving in in the wrong direction, you’ll have to hit the ESC button on the controller itself to stop it.

Bring up Machine Settings in LightBurn, and go to the Vendor settings section at the bottom, and open the X axis and Y axis Settings. Near the top of each will be three check boxes:

  • Invert Keypad Direction

  • Limiter Polarity

  • Direction Polarity

The first (keypad direction) controls which way the arrow buttons move the laser. The second (limiter polarity) controls which side of the machine the laser moves to when looking for home, and the 3rd (direction polarity) controls which way the motor moves in general.

There are only 4 possible combinations of “limiter polarity” and “direction polarity” for each axis. I can’t tell you which is the correct combination, but change those settings for the X axis until it moves properly when you power the machine, then do the Y axis. Once these are set, the next steps are easier.

When the limiter and direction settings are correct, check that the keypad arrows on the machine are moving the laser in the correct direction. If not, toggle the ‘Invert Keypad Direction’ button for whichever axis is wrong.

You will also need to set the ‘Max Travel’ value for the X and Y axis - these numbers dictate the length of each axis, and together define the size of the work area of the machine.


Thanks, All. I’ve gotten things moving in the right direction, but I’m seeing odd things down in Ruida-world. Scaling and speeds are not right, and other things. I’m wishing there was a scholarly forum (like this one) that could help with the black-box world inside the controller.

Here’s a for-instance. I have configured the machine to be 2438 x 1200 mm. (An approximation of 96x48".) Sometimes, at power-up, the keypad display will show X=10,000 and y=10,000. What the heck is THAT all about?

I spent many years doing systems integration work, so this is not a new feeling. IMHO “the truth is inside the box”, and on a good day you have the means to examine the code, or system state info. On a less-good day, you see weird stuff and scratch your head. :face_with_monocle:

I believe that 10000 is the Ruida default for “I have absolutely no idea where I am”.
If for some reason the machine is unable to correctly home itself it displays 10000.

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yup if you disabled or interrupted the home sequence at booting.
If scaling and speeds are not right you did not set the steps right which will probably solve both problems in one go.

Thanks, all. Using these suggestions, I was able to get it to home properly. And I also found an entry in Vendor Settings that allows me to choose which corner is Home. :slight_smile: I think that’s the long-tern nome of the same value that @Enno was taking about in New Device Wizard.

Is this a Ruida controller, sorry if I missed which controller. I’m interested in the ‘home’ in any corner. My understanding was the Ruida homes at using LmtX-, LmtY- for 0, 0 or LmtX+ and LmtY+ for max, max. It would be educational to mess with this. Could you do 0, max? with the different inputs? I will look in my vendor settings, but don’t remember that option.

Can you specify? Thanks…

The controller in question is a Ruida 6445. My table only has endstop switches at Xmin Ymax, which is the rear left corner. I suppose it would be educational to suss this out, but only if I had limit switches at the other ends of X and Y. Having everyone in the shop hearing the steppers growling loudly in protest at the “wrong” end of the axes was a substantial disincentive for experimentation. Now all I have to to is get the Coherent Laser G150 to light up, and i’m in business. (RF modulated CO2 with analog control.) Book says it will work… :crossed_fingers:

My Ruida homes in the left rear, it is 0, 0 for the Ruida, wired to Lmt - inputs.

I’m not clear here, what are you referencing?

This did work OK, you just want to change the 0, 0 location?

Are the limit switches wired to LmtX- and LmtY- or LmtX+ and LmtY+?

I only have 7 entries in my 6442 ‘vendors’ settings. What was the one you found to change ‘home’?


Apologies, Jack. The TL;DR is that the home corner is settable in the Device Settings, not Vendor settings.

… which was probably my problem from the get-go. Lightburn sets this once at installation time, and I had forgotten all about it. I am upgrading this Kern laser from scratch: new limit switches, new RUIDA controller, Geckodrive 540 stepper controller, new steppers. When I first started this setup process, there was at LEAST one thing wired backwards (or configured backwards) for both X and Y. I got so focused on the + interaction, and their documentation, that I just spaced out and overlooked the items in the Device Settings.

So, today I’m in good shape with motion control. Everything initializes properly, homes at acceptable speeds, etc.

Today I am graduating to the challenge of getting the Coherent G150 to light up. Seems to be an RF modulated C02 module without pre-ignition. Ruida is sending 2.5v which should get 50% duty cycle, but no zaps yet. Another day in systems integration. :smiley:

I was reading about the RF lasers… I did notice a bunch… of configuration stuff on the Ruida on pre-ignition and such. Mite poke around a little there if you haven’t already.

Glad to help, this is the stuff that drives you nuts, and so often it’s configuration. Sometime you just need a fresh outlook…

You’ve opened your own can of worms with this :slight_smile:

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