I have been trying out a new material over the past few days, a material that cuts too easily for Flux’s material test pattern. For this polyester felt, I need the power to be down around 10–15%. I thought it’d be easy (but slow) to make my own test swatches, but it turned out trickier than I had anticipated.

I started off in Beam Studio, laying out little 8mm squares, spaced 10mm apart. I put each square on its own layer, and gave each one a different power and speed. But they didn’t work: it seems that Beam Studio can fill a rectangle on the screen, but sends only an outline to the Beambox. That was a lot of time wasted.

So I thought I’d go back to Flux Studio and do the work there, but I couldn’t find a way to create filled rectangles in Flux Studio — only outlines.

There seems to be no documentation available for either of Flux Studio or Beam Studio, so I can’t tell whether this is a problem of bugs, intention, or of unfinished feature implementation. (There are changelogs but they list only what’s been changed, not what remains to be addressed.)

For now, I have a workaround: Flux Studio will output filled text, so that’s what I used.

Cutting polyester is very different from cutting wood or paper. The polyester melts rather than burning. If the laser power is even 1% too low, it seems to leave no mark at all. And then, as soon as you cross the threshold, it melts fairly quickly, so speed is all you’ve got to control the cut depth. For this fabric, it starts melting at 10%, and I seem to be getting the best cuts at 15%, running at 10 mm/s (these are the squares that got cut through to various depths). The cut surfaces are fused to a clean finish, not burnt, and they add a little bit of rigidity that helps to keep fine pattern details visible. I’m thinking that felt might be a good material to make the next iteration of the Japanese-patterned lamp faces. For surface engraving, that letter ‘A’ was done at 10%, 20 mm/s. Again, the melting gives a non-burnt, slightly hardened finish.

I didn’t actually know at first what this material is because it’s not labelled well, and the shop staff said polyester but weren’t very confident. The smell is a giveaway, though. As it cuts, the fabric releases a smell like the cheap fragrances in stationery and candy. That’s the esters that the polyester’s constituted from. It is hard to find out what else has been blended into the fabric, however. The manufacturer’s webpage says that their felts are made from “wool, polyester and waste fibres” but, apart from one brand only, they don’t say which felts contain what. One thing that I am concerned about is that the waste fibres might include polyvinyl chloride (PVC). A product of PVC cutting is hydrochloric acid, which isn’t good for the Beambox’s health.

As for the ester smell: enough of it comes out (and a huge amount of smoke when cutting plywood) that I’m thinking about getting some charcoal pellets to make a filter box for the exhaust.