CNC Plotter

Hobby cnc plotter. The use of inexpensive materials.
Most of the units printed on the 3D printer.
Box for the controller is made on this plotter.
The basis of design - aluminum square tube 25x25.
http://www.youtube.com/watch?v=dJQgnGs-r40&feature=youtu.be

Z Stepper motor NEMA 17, X and Y - NEMA 23/
Belt z 300-3GT-6, belt y motor 255 5M - 15mm, belt x and y 5M - 15mm length depends on the dimensions of the machine.
Smooth shaft 8mm and linear bearing LM8UU -4.
Belt can be different, my very hard.
Pulley teeth 15, the width 20, an inner diameter of 8 - 3, pulley teeth 15, the width 20, an inner diameter of 6.35 - 1

sliding carriages carried on bearings 624