A while back I was wondering why we don’t have a pulses-per-inch setting for vector cutting. If I understood the answers correctly, it’s because our laser power can be continuously modulated and we don’t need it.
Well, I wanted to see what would happen if I could somehow fake the setting by cutting a zillion tiny line segments. Some materials are challenging to cut cleanly–looking at you, PETG–so I figured why not try something new.
The short version is, the Glowforge does not handle a microscopically segmented line as you might expect.
Here’s the sample object, a 5 pointed star that is about an inch tall. The lines are made of line segments at what should be 300 segments per inch–so, this should simulate a 300 PPI cut at my indicated Speed and Power.
300ppi star.zip (5.4 KB)
Up close it looks like this.
But when you cut it, instead of zipping along at the speed you set, the head moves very slowly and you end up with more power put down than you expect, and a much bigger kerf than if you cut a normal line. I guess the motion planner is accelerating and decelerating to every segment? In any case, it did not move along at full speed making many closely spaced cuts as I had hoped it would.
If you want to experiment with this technique, you will need to convert your lines to a series of lines and spaces. Someone mentioned a way built in to Inkscape to do this, but I didn’t dig in to it. In Illustrator 6, the easiest way I found was to do it this way.
- Select the line you want to make dashed
- Use the Dash tool to make your dashes and spacing at whatever tiny fraction of an inch you need, like .005 in
- Set your Stroke width to .0001 pt
- Do Expand… and select Stroke. (Normally this would turn your strokes into filled shapes, but in this case, the stroke is so thin Illustrator chops it up into line segments instead)
- Change your stroke back to whatever you like for visibility
(I suppose this might also be a good way to make a series of slits for leatherwork.)
You can accomplish the same thing with a Pattern Brush and Expand commands but I found this quicker.