Have you ever wanted to laser engrave both sides of an item? I was asked if I could cut some key rings and engrave both sides. My first thought was that it wouldn’t be possible. If your laser cutter is anything like mine, you won’t have any way to accurately position an item for cutting. My cutter has a LED cross hair projector which would get me to within about 6mm (roughly 1/4″) but no closer. Less than a millimetre out and the key ring would look terrible.
Then I had some inspiration: If I could cut two mirror image items, and engrave one side, I could use the cut outs to accurately position the items if I could keep the blank in exactly the same position. I think you could adapt this idea to laser cutting and engraving pretty well anything.
I got the idea of working with jigs in the laser cutter while watching a “Laser Origami” video on YouTube:
What I’m doing is completely different, but the seed of an idea of making a jig was planted. I made an MDF jig to hold a blank in place and cut two butterflies. Each is a mirror image of the other. The jig has feet which fit snugly into the holes in the laser cutter’s bed. I marked one corner of the blank. So long as I don’t move the X or Y axis until the job is complete, I can replace the butterflies accurately.
I put the butterflies back into the blank and hold them in place with masking tape. Then I defocus the laser by 4mm and engrave butterflies’ markings. Then swap the butterflies over and engrave again.
Cutting and engraving relies on the RD Works laser software taking the position of all the items in a job into account, even those that aren’t output. I created the two DXF files from one Corel Draw image — one with the blank’s outline and the butterfly outline, the other with the blank’s outline and the butterfly details.