LEGO Stencil

This is my take on a stencil for attaching LEGO bricks with paper. Use the stencil to draw circles on a piece of paper, which you then cut out with a single-hole punch. You can then attach bricks together using the pieces of paper to make flexible models.

I could explain that better, but you should really just watch this video by Playfool (which talks about an actual LEGO-branded hole punch that was sold in Japan).

There's also a LEGO stencil by Brown Dog Gadgets, and they offer some other ideas for projects.

My version provides a 4x4 grid of holes, and has lots of room to grip and hold the stencil using your left or right hand. The stencils in the photo have “EFK” debossed into them, as they were used for Engineering For Kids summer camps, but that's not in the STL file.

The stencil can be printed with opaque filament, and the notches on each side enable you to line it up with the edge of a piece of paper. I mass-produced them in four solid 0.25mm layers.

After playing around with the settings described in How to print glass (and the additional tips offered in remixes and comments), I tried using Overture transparent PETG with 0.10mm layers at 250 degrees and 15mm/s print speed. It took an hour to make one stencil, but the result (shown in the second photo) is pretty good. I might try to make it a little thinner.