View Full Version : Frustrating laser engraving problem

Sam Johns
05-21-2010, 11:33 AM
I am looking for some information on a banding issue that i am having with my laser. I have a 2005 VyTek 65W MLT4496 with a 1.5'' lens along with the most recent Corel Draw and PhotoShop and also PhotoGraV. Also all that the laser is used for is granite and marble engraving. The problem that I am having is that the laser is banding throughout the entire image on the Y-axis. The first thing I tried was to rotate the image 90 degrees but the banding stayed on the Y-axis. After several tries with different laser settings and no improvement I decided to try a file that VyTek supplied with the laser just to see if it is something that I am doing wrong on the rendering side of things. The VyTek image came out perfect, it had no banding and was a crisp clear image. Then I tried my own image again and it resulted in banding. I am currently running marble as of right now and noticed that the banding really shows up on the marble compared to granite but I do notice banding on granite also. The question I have is why is the VyTek supplied image coming out perfect and mine is not? Is it something I am doing wrong in PhotoShop, PhotoGraV, will a cheapo scanner cause banding issues? Any help or suggestions will be greatly appreciated.

Dan Hintz
05-21-2010, 11:40 AM
Are you resizing your image after being processed by PhotoGrav?

Any banding (whatever the cause) will show up more prominently on marble compared to granite as marble is typically a higher resolution substrate.

Sam Johns
05-21-2010, 11:55 AM
No, the image is not being changed after being processed by PhotoGraV.

Dan Hintz
05-21-2010, 12:40 PM
What is the resolution/size of your image? Res/size of the Vytek supplied image? Final res/size of both after PG?

Scott Shepherd
05-21-2010, 12:54 PM
One thing to try is to take your original image, apply a small gaussian blur to it and then process it again. I don't understand it all, but I've had photos that looked great and they would band after I resized them. I applied the blur to it, very small blur, and ran it and no banding.

That wasn't in a Vytek, but it's something I have seen before. If it engraves fine with their image and your image won't, then it's the image for sure. Blur it and try a small spot if you can.

Doug Griffith
05-21-2010, 1:28 PM
It sounds like a resolution issue on the Y-axis. I'm not a Photograv user but I'm guessing it's the culprit. Probably a setting.

In Photoshop, overlay the image that was processed with Photograv on top of the VyTek supplied image. Use layers at pixel resolution (Actual Pixels). Color one layer to aid visibility. Then look for pixel shift on the Y-axis. At least then you'll narrow down what's happening.

Bill Cunningham
05-25-2010, 9:06 PM
Some other weird things can cause banding between photos. Make sure the processed photo res is the same as the engraving res.. I.E. engraving a 300 dpi Engraving file at 400 dpi can cause banding. I have also found that some photos that have been scanned from textured paper can throw the light around a bit, as well as reproduce the actual texture. Professional photo paper (usually has 'do not copy' water marked on the back) in some case actually will not copy without weird halos etc.. But the usual culprit is mixing dpi's

colin smith
05-27-2010, 1:29 AM
Hi there, have you tried altering the scan gap. it takes longer to burn with a lower scan gap, but it may help


Rodne Gold
05-27-2010, 3:01 AM
If the other suggestions don't work you could try a 2" lens and if you have a way of tuning your bidirectional settings (IE registration between the scan going left and then right) then do that.
You could also try just defocussing your 1.5" by a teeny bit if you dont have a 2" lens

Niklas Bjornestal
05-28-2010, 3:03 AM
Laserpro has a setting called scaling where you can adjust the engraved image to compensate if it's not the correct size. (eg. a 10" object might be engraved as 10.02"). If using compensation you'll get banding when using images processed with photograv.

I dont know if vytec has something similar but it might be worth checking.

Kevin Huffman
06-14-2010, 12:15 PM
The GCC machines can be ran 2 ways.
With a 110v AC connection and a 220v AC connection. The power supplies are auto switching so it allows either to be used. I am not sure if Vytek can be or not.
I have noticed that if you run a machine that is 40w's or greater on a 110v AC connection, you almost always run into a banding issue. Once we connect them on a 220v AC connection the banding goes away.
Is your 65w running on a 220v power connection?

Panos Fioros
06-15-2010, 12:08 AM
I had a similar problem too. Banding in photographs. I had my bearings
replaced and that solved the problem. Perhaps your bearings are
wearing out?

Sam Johns
06-17-2010, 6:04 PM
Hello again and sorry for not giving an update sooner. We are thinking that the problems might be on the editing end of things. We think that because why would the vytek file run just fine but not one of our files. There are so many settings to change and things to learn with the laser. But we haven’t really had the chance to try all the suggestions offered by everyone yet because we have been busy with other things but plan to try them out very soon. Thanks for everyone’s help.