Interlocking Wood

At Burning man this year I saw some amazing structures made form interlocking pieces of wood. They had the benefit of being both ridged, 3 dimensional, and didn't required power tools to set up after being cut. The previous year I saw the work of Greg Fleishman  who designed the temple this year, and coincidentally also met Rob Bell who makes the Zome structures a few months later. This tool-less construction intrigued me and I decided to try my own go at designing interlocking structures.

First I looked at what I had seen Bell and Fleishman make, which is a panel with a joint piece, and copy some of their most basic work. Many of the pieces they concoct are angular, curvy, and multi axial. I started with a Box.

Usually, I jump into sketch up and start hashing out ideas. THis turned out to be less helpful than I expected, since the object I was creating required more attention to the connection points than the shape itself. So after playing paper, which was hard to find in a computer lab, I settled on a rounded box like object that had 4 radial vertical C's with 2 circle horizontal slabs.

Using illustrator, which I do not recommend, I sketch the cut lines, and realized my material I was laser cutting was the crux of the design. The intersections had to be the same width or the locks and hold with friction (or glue) or the pice would fail to hold rigidity. Using chip board, that was 1/8 inch thick I measured the slots, and saved my file as a pdf. It took 8 tires to get the sizing right. This is the part where I don't recommend illustrator - using a non unit specific vector file format took several tried, even after attempted measuring with the cut program, and scaling. 

In the end though, it's a cute little wooden cub. 

ATX Board Mount

Today I made a holding mount for an ATX mother board (part of a larger project which I'll detail in a little bit). ATX; which stands for Advanced Technology eXtended (wiki) is a common motherboard layout for desk top computers with easy access to the CPU and RAM. The project which I landed on, required 4 boards to line up and run at the same time, in what would otherwise be a server rack. 


My design constraints for the board itself were to mount the board, so that it could be removed if needed by it's mounting points. ATX boards and other mother boards come with hole specifications that show standard points what a manufacutere of a mounting plate (usually inside a desktop) can configure so that a typical board can be placed. I found this hole chart online with a quick google search.

It got somewhat funny after this. This file is a PNG ( or Portable Network Graphics ) (wiki) which is a raster file that uses a dot matrix format for it's image orientation. I will be using a laser cutter to precisely cut holes in the board that I need to mount the ATX board on, so I had to convert it into a vector file that the laser cutter needs to cut paths, rather than the bit map that the raster file is made of.

In an engineering perspective this becomes a little messy- luckily the chart show above gives measurements, so I can replicate the whole file without relying on the possibly resized and inaccurate bitmap PNG file.

Using a vector based art or Computer automated design (CAD) program, such as Inkscape, adobe illustrator, solid works, or autocad; you can follow the spacing (with measuring tools) and place the cut holes (which are also specific- I had 1/16 inch holes to cut). The board I was cutting had 10 holes in a 12 by 9 area, so following the measurements I placed (centered the holes) the cutes, and loaded them into my laser cutter.

I like to practice on cardboard before I use expensive material (which is the picture you see above) to make sure the cut is correct. The power settings vary for material type to material type, and cardboard is a lower power setting than acrylic, but I can see if I have any design issues that way.

After the cut, I place the AT board, and line up the cuts with the screws to make sure that everything fits and is scaled correctly!

Tomorrow I'll be cutting the acrylic, and attaching the board.
-S