You might have noticed that I’ve been quiet the last couple of weeks. I was doing a bit of yak shaving. Since I wasn’t very happy with the body of the robot, and since I didn’t have a wireless connection to the ground station coumputer, I decided to upgrade the body. The difficulties in using a saw and a file lead me to believe that I needed a CNC router to do the cutting and carving for me. So that’s what I’ve been working at. A CNC router. Acquiring the material was interesting, since I didn’t want to spend more than a 100 dollars on it in all. That was a very challanging target. So as you can see, I got drawer slides, threaded rods, a 1/2" MDF sheet, nuts, insert nuts, drywall screws, dremmel router bit, gorilla glue etc. from Home Depot. It all cost me less than $75. Next, I broke open a couple of printers to get at the stepper motors. That turned out to be a mistake. Should have gotten them from ebay or a surplus store. A friend gave me two-stage precision linear slides. And the router is almost ready, as you can see in the attached pic. Just need to cut the verticle lead screw, and replace the stepper for z-axis with something decent (maybe NEMA 23 stepper; right now it slips due to lack of torque). After that, my first CNC router will be finished. For control and interfacing it to PC over USB, I plan to use 3xULN2803A chips (might not be enough; were getting hot during testing) and FEZ Panda. It has plenty of digital outputs to handle the control. If things work out, I might add shaft encoders, and decoding chips. The cost might run slightly over $100. Then, once my hobby budget has again built up somewhat, I’ll start working on my robot again.
p.s. I’ve since received my Xbee shield, so now I can also test wireless connection between robot and base station. But that will now have to wait until I finish my CNC router.