Monday, November 3, 2008

Piling on

I've been having trouble getting the accuracy and resolution needed for the circuit boards for my bot; neither of the two fabrication techniques I had available (laying the circuits out by hand, using a combination of rub-on patterns and hand-drawn lines, and thermal-transfer paper) was getting me the kind of results I wanted (and will need).

Searching for an alternative, I somehow ran across a reference to a DIY laser cutter; reading that article ultimately led me to CNC technology. From there, it was pretty fast and direct to a free Linux-based CNC controller. It didn't take me long to put the two together: using a slightly higher-powered laser to 'cut' the thin copper film on a circuit board to fabricate my circuits.

So, as a result, I've got a couple more projects pushed onto the stack: fabricating a computer-controllable CNC machine (actually surprisingly simple), and setting up a computer to drive it (I've already downloaded the Linux CNC software). Being a cheapskate scrounge, I've already got a bunch of parts that I've salvaged out of old/dead hardware -- including a couple dozen stepper motors (and gears, and sensors, and...) that will greatly simplify things. Conceptually, it isn't that big of a deal; even the reality of it isn't going to be all that tough -- a few dollars in parts that I don't already have, a bit of skull sweat, and a little labor, and I should be good to go.

Oh, if you're interested in getting into the laser hair removal gig, have a look at this eBay search! For point of reference, my research tells me that a laser of "just" a couple of watts (U.S. laser pointers are limited to 5 mW [.005 watts] or less) would be sufficient to (slowly) cut 1/16th-inch aluminum; 10 watts would do for steel.