Hi.
I havde found this for sale:


And I was wondering if it would be any good for a cnc wood router?

It's made for use with a welder or plasmacutter, but it look fairly rigid.
The only thing missig is the motors, drivers and other electronics. And the Z-axis if I want to have one (and i think i do
The price is the same as the micRo ($599) and the size is 300cm X 150cm (google says that is 9.84 x 4.92 in feet) so it would take a full sheet
But will the belts give me too many problems down the road? And how about the tubes and the little wheels used. What level of accuracy could I ahve with a table like this?

I know it must be hard to answer all these questions just by looking at a photo of the damn thing (and not even a very good one), but any input will be greatly appreciated.

In my not very humble opinion that machine does not look like something that could be converted to a router very effectively. Here's why...

The machine looks very light. The gantry supports appear to be made from square aluminum tubes which cannot possibly be very rigid. Also, the connection between the horizontal and vertical tube (on the gantry) does not look very strong.

You mentioned the "tubes and little wheels"...

It's tough to tell from the picture, but it looks like the rails are less than an inch in diameter. At 59 inches long even if they're solid steel you could expect them to deflect (bend) a fair amount under the stresses of routing (and even under it's own weight). If they're tubes you'll probably get lots of deflection. I'm guessing half-an-inch of deflection is likely.
Try playing with the numbers here: Dales Homemade Robots - Beam Deflection Calculators Note that these calculators are for beams supported at only one end.

Are there wheels under the X rails? If not you might find the gantry lifting off the rails when the Z axis moves down.

The wheels on the trolley (I think that's what they call the thing the tool rides on) don't appear to have any adjustability, I wouldn't be surprised if there's some play between the wheels and the tubes they're riding on. Play is bad.

Lastly about the belts...
(P.S. I tried to keep this short...)
I was planning to use belts while designing my machine (by "my machine" I mean the machine that exists only in my dreams and computer). I've heard good and bad things about them. I'd say their worst "con" is that unfortunately the pulleys are so frigging expensive: belts don't offer much of a price advantage over other linear motion... um... techniques(?)
When I was trying to figure out if belts were viable a few of us here discussed them in the thread over here: http://www.lumenlab.com/forums/index.php?showtopic=26118
The biggest concern I had was whether the belts would stretch or not... The prevailing opinion I've been able to find is that they do NOT. I've searched the net quite a bit and IIRC I was only able to find a single, solitary person who had first-hand experience with belts stretching ON A CNC MACHINE. It's possible that person mishandled the belts (the reinforcing fibers inside the belts can apparently be damaged fairly easily).

Hi, I spoke with the man selling it, and he confirmed that it was indeed tubes and that they could bend a little.
Thanks for the help. Now I just have to pile up alot of money to built my own from sratch.
So, I guess I will be posting again soon with more questions on that.