Week 4 - Computer Controlled Cutting

Press Fit Construction Kit

For this week's assignment I came up with the idea to use an interlocking spear and receptacle with the intention of also creating a hinge. The kit would consist of only a few pieces that can be combined in endless combinations.

To figure out what design I wanted to go with, I just drew up a few ideas in AutoCad. Once I had the concept I then needed to fine tune the actual press fit joint. To do this I created a test piece which would show me what dimensions created the best fit. Below is a screenshot of the original test file, and the test joint. The spear piece had 2 different tips to try, and the receptacle piece had 6 different. Once I determined which had the best fit I could then begin designing the remaining pieces for the kit.

I originally designed the test piece for spare acrylic that I had, which was 0.118" thinkness. However using the spear piece 2 or 3 times the acrylic was too fragile and broke. I reconfigured the test piece for the stock acrylic at the lab which was 0.125" and also appeared to be more durable. This seemed to do the trick and I moved forward to work on hinge pieces.

There was still plenty of room left on my 12"x24" piece of acrylic after cutting the test pieces, so I figured I would try to maximize the remaining space. After measuring the unusable space I made cut lines around it in Inkscape, as you can see below.

Here's a few examples of the kit in action!

Future considerations: I would like to explore future modeling with the hinge. Also, I need to laser cut more 90 spears, and more double wide receptacles. It turns out that these are quite common in just tinkering. I would also like to make an articulating gripper arm, and maybe some sort of animal with bendable limbs.