Full Version: Substrate Surface Variation...
From: Wysard (CWYSARD) [#3]
19 Dec 2006
To: ALL
From: Harvey only (HARVEY-ONLY) [#4]
19 Dec 2006
To: Wysard (CWYSARD) [#3] 19 Dec 2006
You can get away with a bit of variation for rastering by focusing in the middle of the height. That way it goes out of focus half of the amount. In vectoring the variation is also limited, you need enough power to go through the thickest part of the item and not go out of focus enough to cause visible burns on the thickest area.
If it is an even thickness but tilted, you should use just enough power to cut the edge, the center will then take care of it self. Again focus at the center of the height.
From: Dave Jones (DAVERJ) [#5]
19 Dec 2006
To: Wysard (CWYSARD) [#3] 19 Dec 2006
From: Boz (CHEDDARHEAD) [#6]
20 Dec 2006
To: ALL
Rule of thumb for depth of field of focused laser beams through a lens
1.5" fl lens - maybe .100"
2" fl. lens - maybe .200"
4" fl. lens - maybe as much as 3/8"
I have gotten away with these kinds of depth of field variations on some materials when engraving. If your graphic is not too detailed, you might be able to get away with a little more. Now for vector cutting, you probably won't get away with as much. Your cut quality through a piece will change drastically as you move away from the focus point.
When I am cutting something thicker than 1/8" thk., I usually run my focus point about a third of the way down into the material. This helps keep the edges of the cut a little straighter.