The general concept with a CNC Router is that you use a computer and motors to move a cutting tool around a table. The cutter can move in all three dimensions allowing you to cut anything from straight lines to intricate carvings. Once we had found some plans and an on-line forum to guide the build, we were set; we had 3 weeks and a limited budget but we were determined to get it right. We decided that we should be able to process full sized plywood and other sheet materials, so our cutting bed needed to be large enough for that, and we would probably want to carve architectural details and various shapes out of foam so we needed several inches of cutting depth. With our basic requirements in place we started ordering the legion of parts we would need, from simple things like steel tube and MDF to more complex things like stepper motors and controllers. While we waited for those to arrive, we pored over plans for our machine and learned everything we could about CNC machines in general.
In addition to the physical machine, there was the software and control system to consider. Typically in CNC (Computer Numerical Control) machining, there are several steps in making a plan into a reality. You start with a drawing of the thing you want to make. This is drawn in a CAD (Computer Aided Drafting) program and then that file is loaded into a CAM (Computer Aided Manufacturing) program that turns it into code that the CNC machine can understand. My research led us to some flexible and affordable CAM and CNC software and we built the control system from components recommended on-line.
As soon as the machine was completed it started earning its keep. The machine has cut parts for three theatres already, and we’ve found new ways to use it that save us time in the scene shop and create an excellent finished product. The machine is capable of cutting with accuracy in the thousandths of an inch (for reference, a piece of paper is about 4 thousandths of an inch thick) and the ability to cut repetitious parts without variation is fantastic.
The project has been one of the most fulfilling I’ve worked on at the Rep or anywhere. I was able to engage my interests in mechanics, computers, and building all at the same time, and the product allows us to add even more creative solutions to scenic challenges to our arsenal. The intricately textured walls onstage for Opus are a small glimpse into what we can now create quickly and efficiently in the shop, and we’re still learning more ways to use the CNC Router nearly everyday.
To learn more about how our new CNC router came together and get a look at photos from every stage of the process, check out the forum that Brian worked with here.