How to add connection bridges to 2D design? (for laser cutting)

As the last step before sending a design for cutting to the laser cutter, I want to add little connection bridges. Their purpose is keeping all cut parts together. My idea is to still cut them, though at lower power, and so not all the way through. I want to automate adding the bridges, in order not having to think about them when I do the original design. Also that way I can quickly adjust their dimensions.



The algorithm for automation could be as follows:

  1. At every point, draw a small circle (possibly on an additional layer Circles).

  2. Split the design using the circles.

  3. Select what is inside of the circles.

  4. Move the selection to the layer Bridges.

The first two steps look straight forward to script. I don’t know, however, how to do the last step. How can I select what is inside of the circles?

As I’m writing this message, one idea that comes to my mind is to utilize SelSmall because the bridges will be the smallest parts. That seems to solve the problem. Still I’m interested in your thoughts! And maybe it’s even possible to solve the problem without any scripting at all.

The classic “brute force” method would be to get something like the midpoint of all the split curves, then test for “insideness” with the circles, using the PointInPlanarClosedCurve() method. If the midpoint of a curve is inside a circle, it’s a bridge.

HTH, --Mitch

Thanks, Mitch!