Thinking about building a CNC machine? Hacked Gadgets forum member, Aaron Bowser has a site loaded with information on how to build one. Not only is there helpful information about his design, there is also a vast number of links to other resources.
“The mechanical design of the machine was based on a survey of CNC machine websites and on the availability of used and surplus parts. A y-axis gantry style, similar to the one used by Axxus Technologies, was selected. The stepper driver board currently used in this project was created based on the application notes from the UN5804B stepper driver from Allegro Microsystems. Each board is controlled by a step and direction signal. The UN5804B chip has been hard wired to run in half stepping mode with output constantly enabled. The UN5804 chips are only capable of driving 1.25A max current, but all of the motors that are used have current ratings above this value. In order to solve this problem, I added IRC’s IRL540 power HEXFETs to drive the motors.”