This is a clip for mounting tools like this pen holder to the stock Da Vinci 1.0a (probably 1.0 will work, too) print head. I used it to turn the Da Vinci into a plotter. The clip mounts very quickly.
The OpenSCAD file generates screw holes or, if you send the mounting bump diameter to 8.5, mounting holes (circle+square) meant to mesh with the ones in the pen holder (well, a little filing was needed), which I then welded to the tool clip with ABS slurry.
You could (perhaps with some remixing, and lots of care about safety, using laser-safety glasses, etc.) use this to help turn the Da Vinci into a laser engraver.
XYZ DaVinci 1.0a with Repetier
I used Slic3r to generate supports for the catch lip. These were very hard to remove. :-(