Laser cutting the Danger Zone coasters with the proper kerf offset for a good fit produced a pile of waste pieces from the other side of the kerf that seemed too nice to throw out. A bit of rummaging in the Basement Shop Warehouse Wing produced a battered magnetic sign that fell off the side of another truck and some casual searching suggested the material was laser-cuttable, whereupon this happened:
The trick is to cover the label side of the sign with adhesive sheet and the refrigerator side with blue painter’s tape, thereby simplifying the inevitable cleanup. Cutting through the adhesive produced poor results, perhaps due to molten adhesive or the sign material (which is almost certainly non-laser-safe PVC, alas) flowing into the cut and contaminating the process. Cutting through the blue tape worked reasonably well, albeit with a disconcerting shower of sparks.
The cutting pattern is the shape outline inset by about 0.5 mm.
Peel off the blue tape, remove the adhesive cover layer, align the outermost shape, press it down, add the rest, then admire the results:
The obvious difference in the “filament” size comes from two different kerf offsets, both on the order of 0.15 mm. It makes a big difference in narrow objects!
The Autonomous Object coaster created its own pile of scrap and you can see the gaps created by the mismatched kerf offsets:
Not works of art, but they came out nicely given where they started.
The Smell of Molten Projects in the Morning 