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.htmPhil