I’ve just got to the stage of setting up the stepper motors for X and Y and I’m really struggling. I’ve read the Lightburn help docs, and also had a look at a couple of YouTube videos, but have not been able to sort it out at all.
Some specifics:
1.When I start the machine, the Ruida displays X Y and Z as 10000, 10000 and 3000 respectively.
2. I have read conflicting advice on what the direction polarity and the limiter polarity settings actually do. One source suggested that limiter polarity changed the sense of the limit switch from NO to NC, while the Lightburn docs say it controls the direction the steppers move when homing.
3. Is there a specific order in which the machine homes the X and Y axes? What happens if the X limit switch is reached before the Y, and vice-versa?
4. Some settings I have tried seem to home successfully (I have the stepper pulleys loose on the drive shafts for obvious reasons), but after a short pause, the X axis will start up again and move until I press the stop button.
5. I have the limit switches arranged so the home position is bottom left (ie the LH end of the X axis and the end nearest me on the Y). I have set this position in both the Move panel and the Device Settings dialog in Lightburn.
6. If I change settings in the Machine Settings dialog, and Write the new settings, do I then need to hit reset on the Ruida keypad, or will they be immediately operational?
Some help would be greatly appreciated - I thought Mach 4 on my cnc was hard to get to grips with but it was a walk in the park compared to this controller.
We have some guidance on setting up a new Ruida controller here:
https://lightburnsoftware.github.io/NewDocs/ConfiguringRuida.html
#1) 10000 x 10000 means that the controller has not homed correctly, and therefore doesn’t know where it is.
#3) The controller moves both axis at the same time, and stops each one as they hit their corresponding limit switch. When both switches are hit, you’ve found home, it backs off, re-tests, then resumes.
#6) Some settings require a reset (certain changes to Rotary, and a few others, but I’m not positive which) and some are immediate. For homing and general machine setup, probably best to reset - changing the step lengths, for example, while the machine is not at 0,0, would cause issues.
Typical behaviour so far is that I start the laser, and it starts attempting to home, the Y axis will apparently home, followed by the X axis which also seems to home but then proceeds to drive itself off to the other end of the bed. This will be followed by a ‘Resetting x/y - press ESC’ message on the Ruida screen. Attempting to move the X and Y axes with the arrow buttons might move one axis in one direction but nothing else. Changing any of the settings in LB such as limit polarity usually results in one of the axes slamming into the limit switch. There seems to be no consistency. It would help if there was some way of forcing it to recognise a 0,0 home position, but I haven’t found a menu setting to do that, or how to tackle the problem of it defaulting to 10000,10000.
Thanks for the link to the LB instructions, but I have already tried to follow them without success.
Ok, another afternoon playing with the vendor settings etc. I started by removing the network cable and using the Ruida menu, just to rule out any misunderstanding I may have with the slightly different terminology used by Ruida and LB.
I now have both X and Y limit switches working, but once the homing is done I can only move the X and Y axes in one direction, and that direction is the tiny distance it takes for the micro switch to click, ie towards the stop.
Maybe it thinks that my limit switches are in the opposite corner to where they actually are.
I thought that the default position for X0 and Y0 was the bottom left, but maybeI need to change the wiring on the limit switches to the X+ and Y+ terminals on the Ruida, instead of the X- and Y- as they currently are?
Most Ruida machines seem to have the “homing corner” either top right or top left. (mine homes to top left).
Your switches may not be where your controller expects them to be. I don’t see anything in the 6442 machine settings to change the homing corner. (maybe I’m just missing it) Don’t know about your 6445.
Did you just assemble this or was it a working machine at one time?
Is this something you have built? If so the next two questions don’t matter 
What did you do to start having these problems.
Is this a ‘stock’ china machine?
The Ruida uses it’s limit switches to determine if home is 0, 0 or max, max. Generally the Ruidas’ inputs are pulled low on activation (NO switches). The “Limiter polarity” changes the detection to a ‘high’ for activation detection (NC switches).
This is similar to the ‘Wind’ and ‘Status’ outputs which are really output sink configuration. The device to be controlled is connected to 24v and the Ruida completes the ground when active.
LmtX- and LmtY- are the limit switch connections for a 0, 0 home. The + suffix indicates the max, max home location.
Reading your question is one that I have had… My machine has limits at the rear left for X and the rear right for Y. These are wired to the - input of the Lmt sense inputs. The Ruida sets itself as home 0, 0.
What happens to the coordinate system when you flip it? You have your 0, 0 hardware setup to home at the front left, yes? Indicating to the Ruida that this is 0, 0.
On my machine, home is rear left. Meaning with an increase in X moves it to the right. An increase in Y will move it towards the me or the front. If 0, 0 is the front left, like your machine a increase in X will drive it to the right, OK. An increase in Y will drive it towards you, ouch…
This is speculation but it comes to mind, if we assume Y is max, then can we connect that limit switch to LmtY+ indicating to the Ruida that Ys home is max, not 0? That would tell the Ruida that home is 0, max.
I have no idea if the Ruida can do this. I’ve contemplated it but only have mentioned it here.
The reason that the Ruida is more of a pain, is that it’s much more capable. That’s part of the bargain. The other part is it’s Chinese so it’s not entirely clear on what they mean by some words or phrases.
I keep forgetting to ask if you have adjusted the limit switches properly to detect the object? They have to be within about 3 to 5 mm of the ferrous metal for detection.
Good luck
Thanks Jack - very detailed. Yes, it’s a new build, based on the Further Fabrication model. I have spent a few hours again, and finally sorted it out. I think last bit of the puzzle was realising that the Limit Trigger setting is for machines which have limit switches at both ends of each axis (which is normal for a cnc router, but seems not to be for lasers which instead rely on what I would know as soft limits). The other problem which you hinted at was the lack of any documentation from Ruida coupled with their cryptic descriptions of some of the menu items. I still can’t claim to have a complete understanding of it all, since some of the settings were achieved just by trial and error - I was hoping to come back with some sort of definitive step-by-step guide to the process. Still, I got there in the end thanks to a combination of help from here, the LB documentation and one of Matt’s YouTube videos.
Thanks to all. Now I can get on with sorting out the Z axis (which should be a lot simpler) and fitting the laser tube, mirrors etc.
Generally you can’t turn on ‘soft limits’ without ‘homing’ enabled and you can ‘home’ without limit switches. Besides servos, most machines have no idea where they are at power up. Some dumb human may have moved it… I had them on both ends of my cnc and one that handled both ends of the Z axes. It allows you to home it to any corner, but it may not be the 0, 0.
Once the machine knows it’s ‘area’ it knows not to go out of it. This is done on grbl by the soft limits. The Ruida can see the whole ‘file’ and will halt if you have ‘slop’ before even attempting to execute. The grbl is a streamed to the controller by your computer, so it doesn’t know beforehand if you are going to ‘drive it off the cliff’ so to speak. Grbl allows a ‘check’ option so you can feed it the code and it will check if it exceeds the ‘soft’ bounds set by the configuration, after it homes.
Glad you have the bugs worked out… Have you seen any of Russ Sadler videos? Very informative.
Take care
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