Hi Gorbo,

The sliders with the belts inside do not look suitable for CNC, judging by the spec on page 36:
http://www.automotioncomponents.co.u...ven-stages.pdf
Running parallelism 0.8mm
Repeatability of positioning 0.1mm

I think these are more for moving objects around, say on a production line.

On the subject of belts and motors, they are often geared rather than direct drive. They tend to make more sense on larger machines, although small ones do have them also.

Noise
Routers are noisy, due to the use of Universal motors.
Spindles running from a VFD are much quieter.
As a woodworker you'll already know that the limiting factor will be the noise of the cutting tool in the workpiece.
Direct mounting of steppers onto a metal frame, with fairly stiff coupling to the leadscrew will transmit alot of noise into the frame and make it louder. You could experiment with rubber tube couplers (more backlash - but could be OK for woodwork) and wooden mounting brackets for the stepper.

Hoods are useful for noise, and also catch the dust that the extractor missed.

On the subject of cost, you might want to budget for about £2000 as a starter.