There’s been some discussion about using AI to round corners in cuts and scores to try to avoid the problem GF has with making pinprick-sized spots where the laser dwells on a sharp corner for just an instant as the head comes to a stop and then takes off in a new direction. The idea is to substitute short curved paths for sharp corners making it possible for the head to move continuously. Yes, it’ll have to slow down as it changes direction, but if it never stops completely, the effect of having a bit of extra energy dumped into the material will get spread out a bit, reducing the effect.
Since I didn’t find too much in the way people actually doing it here on the forum, I decided to give it a try. I created a table of star-shaped scores and varied how much the corners were rounded and the speed+power with which I scored them. I chose white cardstock as the material because it’s pretty hard NOT to burn a hole through on engraves with corners.
Here are the results:
The columns vary by how much the corners are rounded (0.000" - 0.020" in 0.005" increments). The top row was scored with a speed of 500 and a power of 6. The bottom one used 200 and 1.
As you can see, when the head is moving at speed 500, the pointy corners are burned through even when the rounding is 0.020", but when the speed it reduced to 200, the burn-through goes away when the corners are rounded to 0.010". On the obtuse corners between the star points, even rounding the corners to 0.005 prevents burn-through.
As you can also see, there is still one burn-though in every cut. It happens not at a corner but where the cut begins and ends.
All of this is consistent with what you’d expect. The amount of “extra” energy that gets dumped into the material depends on the how much the head needs to slow down as it goes around a corner. For a given corner angle, a slowing the speed of the score (or cut) decreases the amount of rounding you need to avoid burn-through. And for a given speed, you need less rounding as the corner angle increases.
For the record, here’s how to round corners in AI.
- Select the paths you’d like to round the corners on.
- Choose Effects/Illustrator Effects/Round corners.
- Enter the amount of rounding in the pop-up.
If you save your design in AI format, you can go back and change the amount of rounding using the appearance panel. When you export to SVG, the rounded corners get changes to paths the GF can understand.