Sunday, May 27, 2012
Starting this project out I thought I a lot about the types of motors that would work the best. I obviously needed a motor that could be controlled precisely, but also offered speed and torque enough to move two independent platforms for the x & y axis. Since I'm not an engineer and this was really my first stab at any time of motor control I had to do some extensive research.
Thought about using the tons of DC motors I had laying around, but after a few in-depth Bing searches, stumbled upon this tutorial by Tom McWire over at Instructables. Wow. I had originally planned on keeping the X & Y axis on 1 plane, however, after seeing how Tom tackled the process, I knew this was the direction I was heading. This design wasn't new to anyone who had dealt with CNC milling before - but it was new to me.
Knowing I had to dig up some steppers, I immediately hit up our community garage sale to see what I could scrounge up in the way of flat bed scanners or old printers. A few hours, a funny look from my wife and $20 later, I had 2 inkjet printers yielding 2 usable steppers and 2 all-in-one yielding 4 good steppers to start playing with. The key to this story is that with one of the all-in-one printers that I picked up, they guy gave me a DVD player that I was going to throw into my recent HTPC build - well, dumb me, the DVD drive was IDE and not SATA so it was useless. I was in the mood for taking things apart to salvage, so I thought I would go ahead an dismantle this while I was pulling apart the printers. To my surprise, there was a little stepper motor driving the laser on a set of rails that were practically already built for moving is a straight, square line. Perfect. From that point on I build the Word.A.Bot with that in mind... bummer since I just bought a bunch of printers (still have many plans for the bigger steppers, and the GRBL shield is perfect for most sizes), but a quick trip to Goodwill and I had 3 DVD drives complete with everything I needed to get my project rolling... now how was I going to mount it all together. Easy. With man Legos - aka, PVC pipe.