Ruida - Wobbly lines and shapes not placed correctly

[anakaine (Simon)]

I have a blue and white Chinese 1060 laser, which for all intents and purposes had k40 hardware up until a few days ago. It’s now sporting a Ruida 5432G controller, new stepper motor drivers, the same 36v stepper power supply, the same steppers, and the same laser power supply. The Ruida controller got a new 24v supply.

I’ve tracked down and squashed a lot of implementation bugs so far, from homing positions, to inverted axis, etc.

I now have two issues to track down which I’m struggling with a little. I suspect they are related.

1. Lines are ‘wobbly’. I’ve included a couple of photos to show what I mean. Previously I had very crisp, clean lines. The old controller did not have settings that I could investigate for re-use, however.
2. I have a design with a circle contained within a square to test the ability to draw straight lines, sharp corners, and to track the position of the stepper
   throughout the circle. The square and the circle, when engraved, do not align. This also happens with text, with letters overlapping unexpectedly, sometimes. This happens regardless of if I’m pressing the Start button on the PC in Lightburn, or sending the file to the controller and pressing start on the Ruida controller. The photos show a shift left, and separately a shift up.

I have tried, based on another post, adjusting the Speed Factor % setting to 50% to fix the wobbly lines. This didn’t seem to help at all.

Laser settings are 150mm/s / 15% power on a 100w laser. Changing the speed up and down doesn’t really seem to affect the outcome at all.

Other info:

• The belts are tight.
• I’ve been through the electricals a few times now, happy that they are well connected, and hopefully connected correctly…
• I didn’t have this issue with the previous controller - which wasn’t lightburn compatible.
• I tried a similar design with RDWorks, and got the same outcome / issue.

[Dskall (D Kallenberger)]

Something is loose. Check your laser head and setscrews on couplers motor pullies, etc.

[anakaine (Simon)]

Not to be dismissive, but nothing is loose. None of the mechanical running gear has been changed, but I have checked over it. That also doesn’t account for the 10mm+ shifts on text and shapes.

Edit, I may have to eat my words on this one - maybe. There is the occasional awkward clatter / grind sound on big changes of direction, and that seems to be causing things to get out of sync. May not be 100% the answer though.

Edit 2: Enabled minimize direction changes, and hide backlash in Optimization Settings: Problem got worse, but there was more noticeable chatter from the steppers etc. That chatter is new.

Edit 3: No chatter when using the Ruida controller to move the head around. Even on direction changes.

Edit 4: Seems like it’s worth pulling the running gear and replacing the steppers, cables, and potentially the pulleys whilst I’m at it. May as well go elbow deep and overhaul everything down to the cable tracks.

[Wyked (Chris Gallaher)]

When checking belts don’t just rely on visual inspection, I just recently spent 3 days trouble shooting a problem, found it was the belt had 2 teeth torn so that they only lifted on one side when under pressure and sat back when not, so looked good visually only found it by sliding belt between my fingers

[jkwilborn (Jack Wilborn)]

Where did you get values to populate the Ruida controllers vendor settings?

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What are you acceleration values for this machine?

It sounds like you are near the maximum acceleration values, from the sounds you claim it’s producing.

You will lose steps when it makes fast moves. Not seeing how it actually runs, it’s difficult to make some suggestions without certain amounts of

The photos are confusing, unless you rotated the the output around between burns. The circle is off in different directions and amounts in the photos… is this a normal occurrence or did you not maintain the same operation between burns?

This is pretty indicative of losing steps… If you notice, one of them is aligned to the right side of the box, but the left side doesn’t reach the box…

@anakaine

worth pulling the running gear and replacing the steppers, cables, and potentially the pulleys whilst I’m at it

If the machine operated, and you replaced the controller, where do you think the problem lies… with all the parts that worked properly?

Don’t do this… you’ll just open a bigger can of worms.

Use your brain, not your brawn.

[anakaine (Simon)]

The values for the conteoller came from scraping around on other posts, then lowering the values further. Im happy to post these up if you or others are willing and able to provide feedback based on experience. Its frankly a bit hard to know what they should be given that the old control software had nothing to describe similar measures.

The one thing that keeps playing through my mind is a damaged cable as I had tondrag things through a cable chain and the old wires are quite brittle. I did not change or remove the servo wires, rather they remained in the chain and thus were subject to the pulling forces as the other cables went through.

As for the change in direction, not sure. I did try a test run from RDWorks via the controller, and also Lightburn via the controller as a file. It could be that theres some different logic occuring when lightburn issues the job vs the other methods.

Would seeing a video of the issue help?

[jkwilborn (Jack Wilborn)]

@anakaine

video of the issue help

Couldn’t hurt…

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If we can find a similar machine, maybe you can try a set of controller settings. I’ve never seen anything this large driven like a K40, but it wouldn’t really surprise me…

I don’t have a problem looking over the configuration information, if you wish to post it.

Make sure you have kept a copy of your current configuration, you can at least get back to that state.

[anakaine (Simon)]

Edit and question: I wound up tightening up the X axis belt tensioner. With the machine on, I cannot move the laser head left or right on the gantry without using unreasonable force. The motor resists me. When I attempt to move the gantry toward me, or away from me, I get a grating noise and the motor does not resist me anywhere near as much. Whilst the grating noise appears to be coming from the rear left of the machine, there’s nothing there but a pulley. Compared to the X axis, the Y axis motor seems to have little to no torque. As in I can resist Y axis panning movement with my pinky and get the grating noise. The motor does not rotate at all (motor shaft doesn’t rotate). Can this be caused by wiring issues, bad stepper driver, or other issues besides a bad motor?

I wound up discovering that the X and Y acceleration settings were not correct, including X being set to 10,000. I’ve set both down to 1,500 and the machine seems to be a little happier, though the issue does persist.

In what seems to be mostly solving the issue above by lowering the acceleration speeds, I’m still seeing some things become offset. Whilst I was able to get the Square, Circle, and Text sample I was cutting to engrave / cut as expected (low speeds, 25mm/s), I’ve not been able to get a material test card or interval test to work correctly. Similarly the Square, Circle, Text test I had going fails if I attempt it at a larger size and set the text to fill.

The material test card has the various components print all over the place, and each row of the material test prints offset by about 34-35mm quite reliably. You can see in the attached images what’s happening.

The interval test is interesting - the hatching/engraving is occurring relatively well, producing decent edges, etc. But each new hatched area, and each new piece of text is offset a different amount.

https://youtu.be/sTRyQDMYVPk?feature=shared
This video was run after the other tests in the images below. Settings were 150mm/s at 10%

[ednisley]

@anakaine

• cannot move the laser head left or right on the gantry without using unreasonable force
• attempt to move the gantry toward me, or away from me, I get a grating noise

Notwithstanding what you wrote about the machine earlier in the thread, its mechanical parts are in poor condition.

With the power off, the laser head should move smoothly in all directions without much effort. Any firm resistance, grinding noises, vibrations, or other irregularities indicate mechanical problems.

With the power off, start by removing the belts. Verify all the bearings operate smoothly and the motor shafts turn smoothly with only slight cogging due to the rotor magnetization. The laser head should move smoothly across the entire platform with little effort; if it does not, then the linear bearings need attention.

[anakaine (Simon)]

Thanks. Youre not wrong about poor condition. That said, with the power off, things move smoothly with no odd noises or sticking points. With the power off, connecting wire pairs of the motor results in discernable cogging being felt when rotating the motor, which I believe is a good thing.

At this stage I need to do a full pull down anyway to both get to the back of the gantry to inspect the pulley at the back and one of the forward pulleys. I also have an issue where the forward 100mm of the gantry isnt usable because the belt jumps one of the forward pulleys, so will address that. Finally, after tensioning one of the belts, and leaving what I thought was reasonable slack (easily deflected with finger), it pulled out of the holder overnight when the machine was off.

At this stage im considering replacing the stepper anyway given the age, related issues, and general maintenance issues, but am having issues finding a suitable replacement. I figure if im pulling everything apart I may as well eleminate the motor itself as an issue as I still cannot get it to have much, if any, holding torque let alone get the axis to work properly.

If anyone happens to be able to dig up a data spec sheet on the following motor, that would be helpful and better than Ive been able to manage, otherwise im chasing a 42x42x39mm dual shaft nema 17 bipolar motor with an unknown step resolution. 42-2100C08S-4

[ednisley]

@anakaine

because the belt jumps one of the forward pulleys

Another horrifying possibility surfaced in a parallel discussion: the machine has the wrong belts.

After considerable back-and-forth produced no progress, this happened:

X axis shifting in fill mode

Ed, You were so helpful when I was trying to troubleshoot my Voccell Laser Engraver that I thought you would appreciate knowing how it ended up. You will recall that I was getting “slippage” in the x direction when printing in fill mode. It did not always occur, but when it did, it resulted in characters that were slanted to the right, and the x-zero would be significantly shifted by the end of the run. The belt had been recently replaced and increasing the belt tension had no impact, sugges…

That would explain events like “pulled out of the holder overnight”.

This may be a case where you must rule out everything else before finding the culprit, but at the end you’ll know everything has been looked at and checked out. Bonus: you’ll be familiar with the guts of your machine and can recognize what’s going wrong the next time around.

@anakaine

cannot get it to have much, if any, holding torque

What current is the stepper driver set to? For that size motor, a bit over 2 A would be about right.

One of the DIP switches (usually SW4) controls the holding current:

• OFF = half current
• ON = full current

If it’s set to full current and you can still turn the motor by hand, that suggests the driver isn’t doing its job.

While it’s possible the motor has failed, it’s more likely to be a bad joint in the wiring or a driver semi-failure reducing the current. The driver is much easier to replace, so I’d start there.

[jkwilborn (Jack Wilborn)]

Remove the .txt extension…

Data-Sheet-Stepper-Motor-Support.pdf.txt (839.0 KB)

@anakaine

eleminate the motor itself

I suggest you find the actual problem and not shotgun for a simple quick solution. I can bet that all of these parts are not broken.

Generally best case is you fix the issue, but have $50 or more in parts you have to test or throw away… I know what happens here…

Worst case, and most likely, is the problem still exists, and you have added more variables you don’t know about compounded with possible unknown errors in assembly or wiring.

Depending on a working replacement is not always a sound decision… hopefully, what you get works, but if you know the actual cause, you can determine quickly if you got a bad replacement.

Best luck of all, is you will see during disassembly, the mechanical anomaly that has caused the issue in the first place…

You are always safer plying the odds.

IMHO…

[anakaine (Simon)]

So just a small update whilst the saga continues.

To fix the belt I wound up having to pull the entire gantry from the machine. I discovered so many small maintenance issues along the way that its not funny. Worn pulley edges, lack of lubrication, significant buildups of whatever residue has been in the machine (like dried maple syrup), stripped screw heads, couplers that are impossible to undo (loctite), etc. The gantry is now back together and aligned to within 1mm corner to corner, mirrors installed and laser largely centred and belts connected and tensioned etc. Because this was such an annoying job and likely to require future attention Ive connected wiring back together with chocolate boards so I can disconnect as required. The air line connection now has a 6mm push-connect joiner at the edge of the gantry so that it too can be easily disconnected.

Some issues persist from before, making this a frustrating experience.

The X axis stepper motor still has has a squeak / squeal that happens mainly on a change of direction. Changes in supplied amperage and ensuring that A-A+, B-B+ are connected appropriately, etc has not helped. The motors appear to have no way of accepting lubrication, and google suggests they are a sealed unit. Ill probably replace the motor.

The X axis is functioning kind of ok at speeds less than 150mm/s now. Ive been going through the scanning offset adjustment settings with some verniers, etc because I cannot even get the test card to engrave without ghosting. The ghosting seems to be an artefact of scanning offset.

The Y axis is functioning absolutely beautifully with the exception of the pulley on the left hand side having no edge on it, and so the belt can slip off. Will attempt to get another pulley.

Im reasonably certain the X axis stepper is failing given the noise.

Given that I located a suitable replacement for the Y axis motor, and premptively ordered one given how difficult it was to locate, I think I’ll pick up an X axis motor and some other running gear. Ive had the machine completely in pieces once so far, cleaned, lubed, and wired and made quite a bit of progress. What seems to be the let down is some of the running gear I’ve not been able to change, maintain, or repair. At this stage if I could replace the entire running frame, gantry, and mounts I would probably opt to do that (but wont, because thats precision work).

One interesting issue i have at the moment is that if I increase my engraving speed to 200mm/s whatever im engraving seems to result in the laser only firing over an area a few mm wide. The head moves the full width of the expected area, but only fires in a strip down the middle. Trying to reason out why that might be.

Edit: fixed typos. Have also ordered a gantry carriage simply because if im in that deep again, and I will be, I may as well get new wheels, bearings, eccentric nuts, and a spare plate I can modify to assist with laser alignment.