Background for My
CNC Router Build
My search for a CNC machine actually started in 1999 when I acquired a Sherline 2000 desktop milling machine and a Flashcut CNC conversion kit. The parts were in boxes thru two home moves. In May 2008 I got interested in building a full sized replica of R2D2. Late in 2008 I finally opened everything up and assembled the milling machine and added the CNC control. I started looking for help. If you haven’t gone there already, the The CNC Zone is a great place to start searching on just about any CNC or machining topic. My initial search for an affordable larger CNC machine came up empty. Most DIY machines cost more than $2000 for the parts or required fabrication skills I didn’t have.
I was encouraged by the December 2008 Nuts & Volts “Personal Robotics” article on the Probotix Fireball V90 CNC router. For it’s price, at less than $1000 for a complete CNC router, it can’t be beat. So close and yet so far. The V90’s working area is 12” x 18”. The body skins for an R2 unit are a little under 19.5” x 28.5”, the body diameter is a little over 18"! The V90 is just slightly too small. I spent hours trying to think of ways that I could ‘extend’ the V90 build to fit my needs.
The links page of the Probotix web site led me to CNC Router Parts [that page has changed and the link is no longer there]. While I was contemplating a design using their parts, Ahren Johnson advised me that, in conjunction with Fine Line Automation, they had just posted a 24” x 36” router design! Between the two sites, and the published plans, it would now be possible to assemble a CNC router big enough to handle all of the parts for an R2 unit!
I’m still working under a tight budget. I thought that with a little work I could make some of the simpler parts using my Sherline 2000. After some research on the Internet, I found that it’s actually easy to cut 6061 aluminum using a carbide tipped blade in a crosscut saw. I also tested my machining and CNC skills by cutting a bearing mounting pocket in block of aluminum. Encouraged by the preliminary tests, I started acquiring the parts and supplies I would need to build my own router. Now, here we are at the end of July 2010 and I'm about to finish the build! [Even though I'm retired, I don't get to work (play) with my toys on a full time basis. :-( ]
Here it is May 2011. I ran into some problems. My motors would overheat after about 30 minutes of running and start to loose steps. While The problem was eventually solved (cable issues, location of G540 current set resistor) I lost about 2 months in testing, dismantling and re-building my system. I now have diagnostics for everything... ;-(