Frankenplotter beginnings

So this is where the build of the Frankenplotter started.

I'd read somewhere -- probably on the post that you can google for "Frankenstein Laser Engraver" -- that you could take apart an old scanner and hook an old printer carriage onto it, and get the beginnings of X-Y motion.  I also was looking into building a DIY CNC and a DIY laser cutter, and Jake was looking into building a 3-D printer.  All of them have the same basic needs: three-axis control of motorized instruments in a precise manner.

Here are some links. Hopefully they continue to point to good stuff and withstand the tests of time:
http://buildyourcnc.com/CNCElectronicsandWiring.aspx (and related pages)
http://www.instructables.com/id/Frankenstein-Laser-Engraver/

 I had an old Epson 4180 scanner that wasn't working any more.  It may not have been working simply because I had fried the 24V 1.4A power supply for it.  I pried off the top cover, which required breaking some plastic snap-in fittings on the inside.

Before:

Epson 4180 with hinged cover removed

After:

Epson 4180 with glass surface removed

Fascinating little beasty and beautifully geared stepper motor.  The motor is in the top-left corner of the picture above, upside-down, connected to a nice gearing mechanism and a long motor band.  It moves the scan carriage across the sheet.  The white bar on the scan carriage is its light.  There was a mirror inside the carriage that would reflect the lit page back into the carriage and then focus it via a prism onto a board containing a sensor, so effectively it was like moving a little digital camera across the page.

The next thing I did was to mount the Frankenprinter carriage atop the scan carriage.  The picture seen here is the Brother printer carriage.  (I can tell because of how the ink cartridge is shaped, with its little aqua-colored tab.)

Epson 4180 scanner carriage with Brother printer carriage mounted to it

After that, I just had to figure out the wiring to the Epson stepper motor.

In initial tests, I was surprised to find just how precise this thing was.  The gearing of the stepper combined with half-stepping yielded a resolution of <> mm per step.  That was about 40x better than I was getting with the Brother printer carriage.