Fastening Laser Cut Acrylic

There are all sorts of ways to connect laser cut pieces, each with its advantages and disadvantages; some are more complex, bulkier, stronger... T-bolt joints, slotted joints, etc. But I haven't seen this one anywhere... Threading a square cross-section length of the plexiglas itself.

Design an appropriate length tab on your piece. The width should be the thickness of the material (I used 3 mm), the length should be the thickness of the part it will go through plus the thickness of the nut plus some margin. I also rounded the ends a little bit; it makes starting the threads easier, but it's not necessary. The mating piece should have a corresponding 3 mm square hole.

Using a tap & die set, thread the tab; 4 mm works well for 3 mm material, which is what I use the most. The ratio should hold for other thicknesses, but you'll want to experiment.

I was able to thread the piece holding it and the die with my hands. It's a little tricky to start, since the die is expecting a cylinder and has three cutting edges and the piece has four corners. Keep it straight, go slowly, and once it's started a bit it gets much easier.

The attached file is a test piece you can try this out on.

It's probably not the strongest method, but it suited my purpose for my current project, and I pass it along to the maker community, enjoy!