Laser cut_plexi-glass joints

Jon Martin & Jason Wheeler

Design Goals

Laser cut_plexi-glass joints

Jon Martin & Jason Wheeler

Design Goals

Joint 1: snap box

the goal of the snap box was to create a joint that wouldn't require glue or any type of adhesive

Joint 2: key lock

the goal of the key lock joint was to create a joint that would maintain the thickness of the material through two separate pieces

Process

Joint 1: The beginning process looked at a typical buckle or clip method to combine two pieces of plexi-glass. This was triggered by thinking about the material rigidity. Chipboard and other flat materials don't have the ability to flex and return to their original shape like plexi-glass.

The first attempt was oversized and produced a very rough and inelegant edge due to the protrusion of the clip through the adjacent surface and the misalignment of the edge conditions. To make this a more elegant and useful application, I looked for tolerances set within the material thickness.

By rastering areas of the edge, I was able to thin the plexi-glass to roughly 1/16" or half its thickness. Likewise, by shortening the length of the tabs, I was able to conceal their rough edge within the material thickness. Using both these operations created a flush edge condition in which the snaps are almost completely concealed. Unfortunately the tolerances at this scale make for very delicate parts which are prone to breaking. Through further development it's foreseeable that these tabs could be configured for easy connection and the ability to disassemble.

Joint 2: The key lock joint was made using raster and vector cut methods on the laser cutter. Voids that needed to be subtracted from the material were rastered out and then the whole pieces were vector cut out of the stock. To get subtracted voids on each side of both pieces, the pieces were flipped and put back into the stenciled piece of stock so that the opposite sides could be rastered where needed.

The process of the key lock joint took a lot of thought, sketching and computer modeling to understand how the joint would work. The tolerance contributed to the twisting and turning of the material when intertwined together took multiple attempts. I had to take into account the thickness of the material and how certain subtracted (rastered) volumes weren't fully rotating because of edge conditions meeting before the rotation was complete. Using prototypes also helped solve where the voids needed to be to match up with the solid parts of the opposing piece. When flipping the pieces to be rastered on the opposite side, it was noted that if I didn't take out the cut stock that was supposed to be void all the way through the piece that it would end up becoming melted to the pieces I wanted to keep.

Specs

1/8" Plexi-glass

lasercutter: raster - 90 power, 13 speed, 300 ppi

vector cut - 26 power, 1 speed, 300 ppi