help please - laser cutting issues jaggered distorted lines

[Clare Taylor]

Hi all

We have a GCC X380 laser and it started playing up in April, by distorting the smooth line when cutting, and would occasionally continue off on a straight vertical line.

Since then we have replaced the x motor, main motor.

The laser cut well for about a few weeks before power drained so we installed the new laser glass tube (with guidance and alignment check from our technician via remote video).

When we installed the new glass tube the water inlet tube snapped (i rotated it to have the sticker 'this way up' which put the inlet tube under the laser tube and on the metal bar which snapped the glass under its own weight).

Not having access to another laser tube without ordering a new one, I managed to fix the glass tube by inserting pvc tubing into the inlet (not far) and siliconing it in place, with a cable tie.

There are no leaks and the laser cuts.

The jaggered lines have started so we ordered new cable ribbons however they didnt change anything.

The only thing I can think of is perhaps water flow now has uneven pressure from going through to a slightly smaller tubing as it enters the laser (where I repaired it) and the flow is causing distortion for the laser beam?

I am at a loss here.

Can someone please help troubleshoot?

This is for our business and our backup laser cant cope with demand.

Thanks in advance.


IMG_4243.jpg

[Bill George]

Either a loose or damaged belt or pulley bearing bad.

[Bruce Volden]

I agree with Bill.
It looks mechanical, belt slop, bearing, loose mirror, dirty encoder.....

Bruce

[Rich Harman]

It looks like the error is occurring at regular intervals. If it is not the bearings, I would check the pulleys for debris (maybe some gunk between the pulley teeth), and make sure the pulleys are properly secured to the shafts.

[Kev Williams]

It looks like the error is occurring at regular intervals...

yup-

bumps.jpg

enlarge this and you can see the guidelines I added- the pic is angled on in several directions due to the camera position so I angled the guidelines to match, as best I could-

the bumps happen in the same place in the vertical plane, the hole in the 'o' got hit too. A couple of places the bumps aren't so pronounced, I put a single line in those places.

So not only are they vertically aligned, they're also pretty equally spaced horizontally-

So as noted above, could be a bearing- note that the rail bearings, if greased, can actually be pushed out of the housing. But, the rail bearings tend to run evenly even if 1 or 2 bearings are missing- but the lens head will have a lot of free-play. Note that GCC recommends greasing the bearings, the bearing mfr's say to ONLY use light machine oil...

But a chunky belt bearing could exactly cause this problem, if the bad spot happens the same place in the rotation. A bad bearing cog tooth could also cause this. And finally, the encoder, which is mounted to and rotates with the servo motors on my GCC, could also cause these bumps, since a dirty spot on the encoder disk will return every rotation of the servo. BUT, what also happens when an encoder starts 'skipping', is that the X axis will continually lose it's place, leading to the engraving 'walking'. However, in a vector-cut run, there may not be a lot of walking...

A bad belt tooth could cause a bump, but only once along the entire length of the X axis...

Bad bearing or bad cog seems to be the most likely--

[Dave Sheldrake]

Your mirrors or final lens is loose...

[Clare Taylor]

Thanks so much for your help guys!!

It turned out to be the brand new x motor brushes wore out as it was installed with the pully belt too tight.

We got the x motor replaced under warranty and installed the new one ourselves, leaving a flex of a few mms.

NOW though, we have a hole new problem.... (will also create new post)



Hi, I have a major issue with my laser and am unable to get help due to Covid-19 restrictions preventing our Australian technician from being able to come to my state and troubleshoot it. This is for my business and we've had ongoing issues for 4 months.

GCC X380 glass tube 100 water later

BACKGROUND

Issues 2 blown X motors - not sure if related or if due to x motor belt tension being too tight but assumed belt tension as both motors went about a week after service and x motor replacement.
2 power supplies blown
1 laser tube died (almost 3 years old so understandable). New one replaced but water inlet tube snapped when rotating tube into position (broke under tube weight as it rested on the inlet tube) We repaired the water inlet hose by using pvc tubing inserted into the hole and securing with silicone and cable ties. No leaks and were able to start cutting with the laser again.

2 weeks ago while cutting the laser made a 'tick' sound and stopped cutting in it's track, the head didn't move from it's last working position and the control panel brought up the firmware number suggesting it reset.
After this happened the laser power supply would struggle to turn on, with the fan flicking every second. Sometimes it would turn on, but now it wont at all.
We have replaced the motor.

CURRENT ISSUE
The laser tube will fire when pressing test fire on the power supply the laser will fire and burn the test wood.
When doing glass laser tube test the laser will NOT fire.
When running a cutting file, the laser will NOT fire, despite the red laser LED light going on, on the control panel, suggesting it's working.
On the high voltage control board, when turning laser on, LED D18 will turn on green, then start flashing radily. The flashing slowly to a slow blink before turning off all together.
I replaced the high voltage control board and on the new control board NO led D18 would light at all.
I made a 3 amp and 15 amp connection wire to override each of the circuit breakers and this did not fix the issue.

The laser is connected a 10 amp single powerpoint with surge protector. No other equipment was running at the time of the 'tick' noise when the laser shut down.
PLEASE HELP