Odd results engraving anodized aluminum

[Brian Lamb]

I got some parts back from anodize that we make and I set up to laser mark them and got some odd results, not exactly sure what the issue is. The hash marks for the ruler along one edge are vectored in, so they are nice and straight. The smaller numbers, the inch markings and degrees came out fairly decent.The logo area is terrible though.... I'm using the same speed and power, 30% power and 55% speed at 500dpi on a ULS 50 watt laser, this is what I do all my anodize at and have had much better results in general.

Any suggestions? Try slower and less power? Seems the carriage is whipping back and forth at a pretty good rate over the logo area, it's rather large, about 3" across, where a lot of my other anodized work is only an 1" or two long so the carriage doesn't seem to get up to as fast a speed.

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[Kev Williams]

Thought about a loose lens or something else, but that would mostly show up at the extreme left & right edges.
Your nonsense is showing up on ALL X edges..

Looks like you have a firing issue, showing up mostly at high speed...

Could be tickle, but just out of the blue..?

Could also be a controller, or a tube going...

Do you have servo's on that? If so, clean the encoders.

[Chuck Vezzetti]

I have a V460 machine with a 50 watt tube and use the standard settings 35 power 100 speed 500 dpi. I don't know why you got those results but I would put a red outline around the logo and vector engrave after you raster engrave it to clean up the edges

[Mike Null]

I'm inclined to think it is a mechanical issue. Something is loose or the bearings need to be replaced. Try cleaning the X axis rails.

[Seann Fordham]

I had a similar problem a while back, it ended up being a bad mirror (slightly loose or something like that), replacing it with a new mirror fixed it.

[Brian Lamb]

Well, I spent the morning working on this.... cleaned the rails, lens and mirrors. Nothing really obvious on the bearings and rails, the mirror that send the beam along the top of the rail from the rear of the machine, was loose, the knurled ring holding the lens was backed off a turn or so. I tightened that up and ran a second part. Some improvement and then I added vector lines around the text and box of the logo and ran again, more improvement and I could probably live with it.

But, in doing all of this, I noticed that the issue must have something to do with the axis reversing close to the engraved area. If you notice in both pictures, but more so in the first one, any of the logo and text that lines up with the 10º and 15º marks, is clear as a bell. Look at the line around the logo where it is directly above the E (10º) and the Q (15º), you can see how crisp all the engraving inline with those degree marks.

Not sure what that suggests, but can I work around by adding a line say 3" or 4" away from the Logo and Precision Square and the web address for that 3" wide section it is engraving that area. If I make the line say the least gray I can, 10% black or I don't know yet if I can make it even lighter, say 1% if I can in Corel, would that line show on the anodize? It would then cause the carriage to cycle back and forth further away from the engraving allowing it to get up to speed and synchronized. Hopefully that makes sense.

Or, is there some software setting in the ULS driver or Corel that determines how much "over run" the carriage does when engraving?

Picture #1 with just the mirror tightened:

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Picture #2 with the vector pass around the text and logo:

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[Mike Null]

In my JC software there are a couple of adjustments dealing with this issue. The one that I have adjusted is called overtook.

[Brian Lamb]

And yet more weirdness.... I think that this whole issue is software related. I added in two lines one at X0 another about 4" X plus of the logo and set them to 10% black (and son of a gun, 10% black fires with enough power to go through blue tape and leave me a darn line on the anodize of the part!*#!). I also forgot and left the lines hairline so they vectored instead of rastered. Now the odd part, the engraving of the logo and text did the same over travel as before, as in almost none, maybe 1/2" to 1" by eye, and yet this time, the sharpness of the engraving is almost perfect, certainly good enough for this project.

Not sure if it's Corel or ULS driver issues, but I'm throwing something thick enough over the part in the area of the last vectored line I added, and going to finish the parts.

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[Ross Moshinsky]

My guess is it's a combination of the following.

1. The laser needs "tuning". This is easily done with the UCP software. Not sure about with your driver.

2. Likely the belts/bearings need replacing. The bearings and belts found on ULS machines are subpar to put it nicely.

3. Driver settings could potentially be tweaked to allow more overrun. I know I can configure it in the modern software to be set as "margin" which will have the laser go beyond each line a bit so that the engraving is more consistent.

If I had to guess, bearings and belts are your issue. An easy way to test is slow the laser down and see if anything improves.

[Kev Williams]

I ask again, does that machine have steppers or servos?

The mechanical aspect makes sense to me somewhat, but the clean engraving across the coordinates where the gantry travels farther left to the degree engravings puzzles me. The extreme right edges of all engraving are the worst as to the 'overspray' look, and none of the right edges change regardless of how far the gantry travels to the left. I'm assuming the machine doesn't engrave 'white space'... And that's the only thing that changed in the clean areas. If something was loose, there should still be overspray on the all right edges, especially the extreme right edge of the logo outline, but there's not.

it's why I'm asking if it's servo driven. My GCC was giving me similar results when the X encoder was dirty- similar, but different; the engraving on the left side was 'walking', to the point the words I was engraving had a reverse slant. Cleaning the encoder disc took care of it.

This machine seems to be doing kind of what mine did, but nothing's walking. And the clean space issue doesn't seem to work with an encoder problem either...

Could be a simple data flow issue, have you changed or cleaned the connector cables?

What's scaring me is that I seem to remember (getting old so.. ;) ) a thread awhile back with the OP having very similar problems, and a new tube was his fix....

Last thing I can think of to try based on past experience:
First, go to your nearest auto parts store and get a can of this:
344308 --Lecta-Motive electric parts cleaner. This stuff is essentially dry cleaning fluid, kinda smells but works like gangbusters. It's completely non-flammable so it safe. You can use in on electrically energized stuff--I've actually sprayed it into running motors, they don't even slow down.

Power down the machine, totally open it up, then find every connector you can, that you can figure out how to unplug- do so, then douse all the connections and replug. If you feel good about pulling and replacing IC chips that CAN be pulled, do the same. You can completely power-wash entire circuit boards with the stuff. Douse the USB or ethernet or whatever cables and connections at the machine and computer.

It dries quick, also the smell might hang around a bit. But the stuff works. Wouldn't surprise me bit that just doing this will fix your problem. :)

[Brian Lamb]

Sorry Kev,

The machine has steppers, so no encoders to deal with. I think this is a software related issue... per my last post before this one, I had added a line, and re-sent the file to the laser, and all the jagged edges pretty much went away. I suppose it could be connecting cable related too, that's a thought... and just the luck of the draw that the last file I sent came through "cleanly".

I did finish this batch of parts and have even done another batch of smaller parts with the logo and they came out just fine. I also sent an email to ULS tech support, so maybe they will have some answers this coming week.

[Ross Moshinsky]

I can tell you almost definitively it's either something loose (which I doubt) or that you need belts/bearings (which is incredibly likely as ULS suggests you replace them every 2-3 years).

[Yuriy Karpov]

also, make sure you use RGB in your corel pallet. and the black is 100% for engraving. Use of CMYK gives you really weird outcomes with ULS.