Epilog laser problem

[Pat Shirkey]

Hi all,
Would anyone know what might be causing this problem - the lines in THE and the O in this picture. It does not happen all the time. This material is LaserMax. It just does not seem to laser as crisp sometimes.

[Scott Shepherd]

Are you talking about the lines in the center of the H and the E? Or the banding like pattern in all of it?

If it's the lines in the H and the E, then it comes from the machine throwing a shorter stroke as it changes how far across the table it goes. You can fix that by putting vertical lines on each side of your finished piece, then length of your engraving. That makes sure the stroke is the same across the entire engraving area. You can make it faster by just putting lines on each side, the length of the text.

[Joe Pelonio]

Slowing it down may help too, but most often this is caused by a dirty encoder strip. How often do you clean it?

[Richard Rumancik]

I am not sure exactly what you are seeing - I can't really make out the defect in the "O".

One thing you could experiment with is using a grey fill instead of a black fill. For example, do a test of the word "THE" the same as you are doing now. Underneath, laser the same word but use a "gray" fill of say 90% black. Sometimes this will hide the raster lines and even out the appearance.

A variation of this is to outline the text in 100% black using about a .003" or .004" line, then use a 90% gray fill as above. I prefer this method if the text is large enough to allow it, as it ensures the outside boundary is not pixelated but solid.

Outlining might not work well on very small test as it may make the text look bolder, but it really isn't necessary for small text either.

You can let the laser convert the gray fill to black on-the-fly. Alternatively, you could experiment with converting it yourself ahead of time (which gives you a bit more control.) To convert it manually, I would convert the text to curves, fill with 90% back, then export out and open in PhotoPaint, convert back to black-and-white using Stuki or Jarvis or such, then bring it back into CorelDraw. Sounds complicated but really it's not that bad. If you want to try this route and need more info let me know. There may be some old threads on the subject as well.

You can experiment with different settings and resolution but don't go too low with the % black on the fill or you will not get complete material removal from the text. I would say probably 80% and up will give best results.

[Frank Corker]

I can't see too much issue with the letter 'o' but I do see the 'HE' both have short passes on it. The suggestion that Steve mentioned should rectify it, but my first thoughts, dirty encoder strip as Joe said.

[David Fairfield]

Do you mean the indentations, or chunks missing, from the left side of the letter E and H? If so, that's an unusual problem which I've not seen before. The first thing I do when I have problems with the output is clean everything, including the encoder strip, and grease the rails as per the manual. Also slowing the speed may help. High speed can cause some blurring when rastering. HTH

Dave

[Pat Shirkey]

Thank you all, especially Joe, I cleaned the encoder strip and reran the project. Amazing what a little cleaning will do. I regularly clean the lens but am a little lax on the rest. I have made myself a sign to put on the laser to regularly clean EVERYTHING!!! btw - I also had an Epilog tech give me a call about the problem because they seen it on here - very impressed with Epilog. Thank you all again for helping me.