Homebrew PCBs

Just looking at the pics these are my guesses, comments interspersed: 
> 1) Are those motors DC gear motors or stepper motors?  They look 
like DC
> Gear motors.

Most likely Stepper motors, there is a great deal of software and 
hardware available to driver steppers from the standard PC parallel 
port for x,y,z CNC machining funtions

> 2) Did you have to make any gears for this device?

I didn't see any, and there really isn't a need of desire for gears.

> 3)  As far as I can see, each axis uses a long worm gear in between 
two
> cylinder beams that keep the drill, etc...moving in a linear 
direction
> (as opposed to rotating with the motor shaft).  But I see what looks
> like a very low thread on the worm gear cylinder in the 
center...that
> makes me think that there is a different variety of worm gear
> techniques/structures.  Can somebody describe the gear structure 
for the
> long worm cylinder-movable part?

A lot of homebrew machines use pipe or drill rod for linear ways, 
ACME screws or conventional 1/4"-20 all thread(threaded rod).  A good 
resource for 
you if interested is www.cnczone.com.  Specifically under Home-Made 
CNC Wood Routers.  I'm working on my machine and have some material 
links at: http://webpages.charter.net/pminmo/mycncpage.htm

Phil