View Full Version : New here - problems, but semi-solved, with ULS M-300

Ian Stewart-Koster
09-18-2016, 2:47 AM
Hi Folks,
I've enjoyed reading many past threads here over the years.
We recently bought a 2ndhand Universal M-300. It's 14 years old, but the tube is a 2012 model.
It ran fine for a bit then suddenly started making horrible grinding noises in the Y axis, as if it was a servo fighting to retain its place - except it's a stepper motor.
It would not home properly, and could not be jogged around the bed properly without the machine convinced you'd reached the limits - yet the lens was still in the middle.
X was fine - just Y was the problem.
I eventually found a loose plug on the motherboard and plugged it back in-it looked like an old PC IDE harddrive ribbon cable lead.
However that did NOT fix the problem.
Several reboots and suddenly it behaved-for a day.
The it played up and was no good. Then it came good.
Touch wood it stays that way - today it has not missed a beat.
I've been racking my brain to think of reasons -it's not the stepper motor itself-I changed that out for no difference.
It can;t be the CPU or motherboard... I did re-flash the firmware, and it made no difference.
If it was the cpu or motherboard or the drive on it, I believe it would not fix itself. It would stay kaput.
So I'm down to thinking maybe a possibly weak part of one of the 4 wires leafing to the stepper motor.
Vibrations in use worsen it, and vibrations or a rest, remedies it?

I still have no idea - except that today it's going fine so far!

Ian Stewart-Koster
09-18-2016, 9:35 AM
I might add, all is going well, except I've noticed an angle on 10mm acrylic through-cuts, as if the X lens isn't quite perpendicular to the bed.
They all slope the same way, and if you cut a 6 x 2" oval shape, there's a noticeable little bump at the start/end point which you can feel with your fingernail.

Mike Null
09-18-2016, 10:08 AM
There is likely a sleeve loose on the split shaft which runs across the x-axis but is the device that keeps the x-axis in the correct plane. Turn the machine off and move the carriage forward and backward. There is probably a sleeve type device on a shaft and it will have set screws in it. I think they need tightening after your align the shaft. The shaft rides on the y axis rails.

Sorry for my non-technical language.

Bert Kemp
09-18-2016, 11:30 AM
I think the angle on 10mm is normal its hard to get a 90 all the way thru

Kev Williams
09-18-2016, 1:57 PM
I currently count 50 stepper motors on my machines, and I've been running machines with steppers for 35 years. Based on my experience, it seems to me your grindy noise is the result of your stepper not knowing what to do...

Causes: a bad wire, bad connection on either side of a plug connector, a bad stepper driver, or the stepper itself. However, you already know it's not the stepper itself. Probably not the driver either.


^^^^ this is a link to a thread I posted a few months ago about the Y stepper in my Triumph acting pretty much exactly like yours. (topic says "X" axis, but turned out to be the Y) Watch my video, and notice the noise my machine makes when the stepper becomes "confused". I'm betting yours' sounds much the same (echo's from the machine itself notwithstanding). Read thru to the end, I (with the help of Rich and others on the board) found and detailed the problem and the fix, broken wire in the drag chain.

I've had a few other motors act like this over the years, the Z stepper on my V3400 cylinder engraver was the lastest, it would do the same thing. That one was one of the spades had worked its way out of one of the incoming plugs enough to make only a 'fragile' connection. Worked great sometimes, but when it didn't, it was screwing up parts by not raising and lowering the spindle correctly...

Joseph Shawa
09-18-2016, 5:47 PM
My Z- axis was making a horrible grinding noise. I adjusted the bolts, tightened the belt when I aligned the table it still made a horrible straining noise when moving. When I reinstalled LaserCut the noise was gone and the table runs smoother.
So, even though I cannot find a Z-axis adjustment in machine settings, I think the stepper settings were reset. Which make me think that your settings are off for the Y-axis.....??

Bill George
09-18-2016, 6:34 PM
On a ULS they use several ribbon cables, my suggestion after 14 years or so I would just replace. Loose connections or plugs would be my next guess. My machine is built like a tank, I do not know how the new ULS machines are fairing.

Ian Stewart-Koster
09-19-2016, 8:22 AM
Thanks for the thoughts & suggestions.
Mike, There's no perceivable slop in the X axis carriage along the gantry, nor the Y axis. I tried that early on to see if any fine tuning was needed.
The beam just appears to have a lean toward the front of the bed as it cuts all the way around a thicker object.
If it spread radially in all directions, that could be understandable, but it's not 'symmetrical' like that it has a bias toward the front right on all sides.
And finding the little 'tit' where a start and end of a cut meet is a bit of a surprise. I get that with the cnc router unless I specify an overlap with it, but I was expecting the laser to be smoother at that particular junction.

However, I'll recheck - because there should not be a change in angle from the X moving left, to it moveing right as if going round a circle - and there actually is, so I'll recheck for some minute bit of slop. Thanks

Jospeh, the Z axis stepper on this one is too fast for my liking, so it's unplugged, and we do a manual bed rise-and-fall to home on on the 2" gauge mark. You just pull on the timing belt by hand. I just use Corel Draw, and click 'Print'... then check the former settings loaded for any particular substrate, and click 'OK'.

Kev- I agree- a bad connection beside a stepper plug connector is the most logical option. Thanks.
Your machine is quick! But 'yes' the grinding noise was rather similar. The difference was when it happened here, it would happen wven when you tried to manually jog the lens about the bed, and when cutting, it moved not at all - I only got straight lines all on top of each other. Yours loses its place but keeps trying to make its way back.
It's for that reason I like the servos in out cnc router, and their encoders - it always knows where it is, and after a reset, it can go back to where it left off.
Plus they're quieter, and quicker than steppers. But with a laser there's no physical load on the steppers, so theoretically no issues there, and a laser might not like the servo's abilities to accelerate and decelerate.

Anyhow, Our Y axis has remedied itself again, and worked four hours constantly for the last two days without ruining anything! (touch wood!) I have no idea where or how to get into the software driver to alter any settings, as if for instance the stepper was changed for one with 1.8 degrees instead of 0.9 degrees per step. I can do those edits on the router easily, but not the M-300.

Years ago one of our vinyl plotters started to behave that way, but turning it off for a day, rebooting it a few times, and replacing a printer lead fixed it - though I can't recall which part was actually the cause of the remedy. Having a coffee break always seems to help though!

Thank you for the link to your trials and tribulations - that also reminds me of our router & me diagnosing the sillies it used to occasionally get.
IN the end I had 2 sets of cables for everything, and when one lot plays up, I just unplug it, and plug in the adjacent one, and it's good for a fair few more months again.

Mike Null
09-19-2016, 11:45 AM

My memory is a bit vague but my ULS engraved on the diagonal in the x-axis. The shaft remedy solved that issue. My recollection was that the shaft was driven by gears and stepper motor moving the gantry in the Y-axis. There were stops on the front of the machine that you could align the shaft to.

19 and 20 in the diagram are the items I'm referring to. http://www.engraversnetwork.com/files/Maintenance-VLS-Desktop.pdf

Paul Phillips
09-19-2016, 11:56 AM
Welcome Ian,
If all else fails, you might try calling ULS support, they should be able to help you diagnose the problem or at leas send you a maintenance manual as a PDF download.
If that doesn't work, PM me, I think I have a manual I can send you.

Kev Williams
09-19-2016, 12:31 PM
Back to your problem being similar to mine-
In my case, the wire that broke- black wire- was likely a ground wire, making my stepper act nuts. However, I would imagine different wire with the same intermittent issue may cause the stepper to work correctly, or not at all, resulting in the Y axis not moving at all.

Ian Stewart-Koster
04-24-2017, 6:01 AM
I wish I'd written up the solution, after I got it going last October, because it just started grinding and groaning in the Y axis again tonight.
(yesterday, and prior to that it was fine)

What's also very weird, is that a simple star file to be cut in acrylic I sent to it. The Speeds in Corel were P=30, S=2, PPI=1000, from memory.
The M300 console showed them as P=0, S=0, PPI=0.

So as well as the wonky groany Y axis, I'm wondering who stole the control figures from the job?
I have plugged and replugged the LPT lead, and swapped them out, and rebooted 3 times - to no avail.

Cooler weather perhaps? It's a shame as I'm in the middle of a bit if desperation to get some stuff done, after getting the nice new replacement tube 3 weeks ago.

Ian Stewart-Koster
04-24-2017, 8:32 PM
The power settings I solved - it turns out the file in Corel was outlined with an outline that was not the 0.25mm hairline, but was fatter, so it was wanting to try and raster it.

But the Y axis issues I wish I could solve... and I wish I'd made notes of the last time I fixed it.
I seem to remember thinking it came good after unplugging and repluggnig all leads everywhere, and also putting the rotary in and running it.

Last night though, that all made no difference, and what's weird is with rotary plugged in, when I pressed the Z button on the console, the gantry moved to place itself over where the rotary attachment sits, and also started to turn the chuck around by 5 or 7 degrees.
It should not be doing both things, just one...

Ian Stewart-Koster
04-24-2017, 9:56 PM
OK,I'm replying so that I know for next time...
after unplugging & repluggng everything last night - including the motherboard & ram,
and double-checking continuity on the 4 leads from the mobo to the Y stepper,
and pushing everything back together, and testing it last night it still failed to operate properly.
I went to bed at a bit after midnight.

After saying a prayer, it worked fine this monring! :) Have faith!

Scott Shepherd
04-25-2017, 8:57 AM
I might add, all is going well, except I've noticed an angle on 10mm acrylic through-cuts, as if the X lens isn't quite perpendicular to the bed.
They all slope the same way, and if you cut a 6 x 2" oval shape, there's a noticeable little bump at the start/end point which you can feel with your fingernail.

A mismatch in start and finish points can be two things on the Universal. One, the material moves. That's VERY common with acrylic. As you cut, the cut is releasing stress in the material and you can see the part move to one side of the kerf. If that's happening, that's not machine related. You can test that by vectoring circles (3/4" or so would be fine) at very light powers, just enough to mark some MDF (MDF works great to test this on). If there is a mismatch then you need to replace your bearings. ULS makes a kit that has belts, bearings, and pulleys. It takes about 30 minutes to install it all. Once that's done, that start and finish points will align perfectly.

For the angled cut, all the same angle, like a parallelogram (that's important to note), then your beam is out of alignment and it's hitting the mirror off center, which hits the lens off center which causing the beam to be at an angle instead of straight. If it's that, then you normally see lines in the X Axis parallel and lines in the Y Axis parallel.

Ian Stewart-Koster
04-27-2017, 8:02 AM
Thanks for the ideas Scott, I appreciate your reply.
On small or thin acrylic, eg 3mm there is no problem.
ON 10mm, there had been a noticable lean to the left on pieces cut., as if the bean was not vertical, but left & right edges had a leftward lean, front and back were OK.
I agree, it is as if the beam is off centre just a tad, but the lens does not seem to be adjustable.

I am sure the bearings and belts are OK.

I spent 7 hours yesterday cutting 6" letters in 10mm acrylic with it, and it was fine, except for the noticably smaller front face, but I was glueing 3mm acrylic over it, so it looks fine with a face overlap of a small amount. 100% power, 0.8% speed, almost 6 minutes average per letter in 10mm stuff.
The start and end points were not obvious at all this time.
Whereas last year they were a defuinite bump as if there ws potential slop or drag/friction in the system.

So far so good - it must be a lead to plug connection I'm thinking, that was the cause of the main problem I had- and after sitting overnoght to settle, it comes back to good again...

Thanks again

Scott Shepherd
04-27-2017, 9:10 AM
I agree, it is as if the beam is off centre just a tad, but the lens does not seem to be adjustable.

Hi Ian, the lens isn't adjustable, you have to adjust the beam through the #1 and #2 mirrors (more than likely #2). Get ULS to send you the alignment instructions. It's not difficult, just takes some patience, especially the first time.

Ian Stewart-Koster
04-27-2017, 9:18 AM
Ok, thanks for letting me know. I figured the mirrors were all fixed, locked, and not tweakable...
I'll have a poke around.

(on a different subject, what RIP do you use for your L26500 ? We have a L25500)

Jerome Stanek
04-27-2017, 9:38 AM
I test if the beam is straight by test firing it into a piece of mdf and then without moving the piece just lower the table a couple of inches and test fire again. the beam should hit the same spot

Scott Shepherd
04-27-2017, 12:44 PM
(on a different subject, what RIP do you use for your L26500 ? We have a L25500)

Onyx Production House

Ian Stewart-Koster
01-08-2018, 12:58 AM
For the record, it was a motherboard repair that fixed it... from ULS inc. great service.