Look I know it's old topic, but Smithy makes Tabletop CNC Mills and lathes. They are extremely reasonable!http://www.smithy.com/products.php?cid=1
As for trying to make one yourself. Having run a CNC Mill and Lathe before I can tell you that you would pretty much need Drewid's friends' garage That to this day still remains in an undisclosed location) to pull it off. $1,200.00 is so reasonable, because a full size can can easily be ten times that. Being as most of the pictures on the posts are gone I can't see if you guys were talking about a real deal CNC Mill or a small 3D "router" that only really cuts one material. I really wouldn't suggest trying to build an actual CNC Mill. You are talking some seriously large chuncks of metal that have to be ultra finely produced.
You could half way build on if you took a really good drill press and made the base plate moveable on the X,Y,Z axis It has to have very precise control of the movement in all three axis. It would be ok for small soft material work. I feel large enough servos to really with out fail handle the X Y Z Axis movement would be the cost of a Smithy almost. I'm All for DIY, but making a CNC in contrast to buying one. I'm gonna hold out for buying one.
IF you guys are really serious about making one yourself then Here's what yo would need to do:
Get a large near industrial drill press.
Get three highish quality drills to take apart for the motors and forward reverse switches.
A computer to control the drill motors movement.
A three axis lathe head carriage.<------ could be picked up on eBay or the likes. Heres a pic
Some all thread. <----- That's metal round bar that has been threaded it's entire length. Comes in various sizes. You'll need 1 long piece for the X and 2 shorter pieces for Y, and Z
You will need to make a strong (preferably heavy) metal frame to hold the guide "ways" for the 3 axis table. It's for precision got to be going no where at all. The frame could be made of really thick hard wood, but where are you going to get Redwood that think and long? I know it could be made of wood, because the Lathe I bought and had until a divorce was a Craftsman from before Craftsman had anything to do with Sears. The motor had been "replaced" on it in 1896. Seriously! Had two huge Redwood planks for the main body each say 6"X14"X7'. Then two huge cast iron sets of legs that capped the ends off. I bought it for $300 from a friends father that had a Machine shop. When I picked it up he told me it had started 3 Machining businesses and a Machining School. You have no idea how much it broke my heart to find out it had been spitefully sold from under neath me
, but I digress.