Guest Post: Circuit Board Prototyping with the DIYLILCNC, by Chris Reilly and Taylor Hokanson

Accessibility is a central goal of the DIYLILCNC project. We hope that this design balances a high degree of precision with a low cost and a desktop-friendly form factor. We’ve spent considerable time developing the assembly instructions in an attempt to make the project easier still for construction by beginners.

While our focus to date has been largely on the design, construction and distribution of plans, we have had some opportunities see functional objects produced with a finished machine. This is the first of two posts that will delve into specific examples of projects that can be made with a DIYLILCNC.

It’s often difficult to concisely sum up what exactly a CNC mill can or should be used for—it’s a bit like asking what a computer is for. The DIYLILCNC can cut a broad range of materials: wood, plastic, light metals and prototyping foam, for example. As long as you work within the size limitations of the cutting area, and the speed limitations of your cutting tool, a DIYLILCNC can fabricate objects using just about any material that can be cut with a Dremel tool. The tool itself is an open device; it’s up to the community to decide what to do with it.

One of the most satisfying applications we’ve seen so far is using the tool to prototype circuit board designs using a 1/16″ thick, copper-clad plastic sheet material. When the top copper layer is broken, parts of the board can be isolated from each other to form electrical connections between circuit components.

Traditionally, this process is accomplished by hobbyists and circuit designers using a chemical etching solution to selectively dissolve areas of the copper cladding. A minor drawback of chemical etching is that it only removes the copper cladding, leaving tedious through-hole drilling to be done manually by the circuit designer. A major drawback is that the byproducts can be toxic, making disposal problematic.

We’ve had great success using a miniature end-mill to cut very thin traces and drill through-holes into the copper-clad board. In the example above, we used a circuit design for a small radio transmitter used for intro classes in the School of the Art Institute of Chicago’s Sound Department. The DIYLILCNC allowed us to prototype a few iterations of the circuit design before having a large batch produced by a commercial circuit board producer. These preliminary design tests are vital to getting a good result in the end product; they allowed us to catch several mistakes and find opportunities for improvement. Having direct access to the CNC milling process gave us very quick prototype turnaround: in the course of one day we were able to run and assemble two complete test boards.

In keeping with our dedication to open-source solutions, we’ve been using a program called Fritzing to develop circuit layouts. Fritzing is a cross-platform development a tool that allows users to document and share electronics prototypes in a straight-forward visual manner. This visual approach flattens the learning curve, allowing non-professionals to access a design process previously limited to electrical engineers and other professionals.

This is a great feature for designers who aren’t electrical engineers, or are just visual thinkers. The best part is that the visual mode is linked to a schematic drawn with traditional electronics symbols, which directly illustrates the translation between visual circuit layout and schematic layout.

As the community base organized around the DIYLILCNC design grows, we look forward to seeing more examples of crowd-sourced applications. In the past two days we’ve been presenting at SIGGRAPH, we’ve heard plenty of interesting ideas: granite tombstone engraving, RC car/airplane parts fabrication, veneer inlays for musical instruments, mold-making, and even totem pole carving.

Taylor Hokanson is an Assistant Professor of Art at Oakland University in Detroit. His art practice uses technology as material to address technology as concept. The presence of altered or hacked electronics, such that their operation is impeded, is a common theme in his work (see the Sledgehammer-operated Keyboard, for example). Hokanson also works in conjunction with The School of the Art Institute of Chicago, where he performs research into computer-aided fabrication and education.
www.taylorhokanson.com

Chris Reilly is a Chicago-based artist, writer and teacher. He received his BFA with a focus on New Media from the School of the Art Institute of Chicago in 2006. Chris is currently employed as manager of SAIC’s Advanced Outptut Center, and a part-time faculty member teaching between SAIC’s Design and Film/Video/New Media departments. Since 2003, Chris has shown work in several solo and group art exhibitions in the US and Europe; he works with modded video games, virtual/augmented reality, scripting/programming and kinetic sculpture.
www.chris-reilly.org
www.rainbowlazer.com