Scott's CNC Controller

A picture of the CNC controller is below. I built it in a 2U rackmount enclosure (from Jameco) so that I could mount it to the rackmount rails in my CNC milling stand.

The core of the CNC controller is 3 gecko 201 stepper drivers. The G201 takes step and direction inputs and turns them into the necessary signals to drive the motors. You can find G201 modules on ebay at a fairly reasonable price. Three G201's are needed, one each for the X, Y, and Z axis.

The G201 can be driven directly from the PC parallel port in most cases. So, the easy way to do things is to wire the G201's to a DB25 connector, which is more-or-less what I did in my case.

Joystick controller:

I also wanted a joystick control so that I could operate the feed without using a PC (sort of a power-feed). I purchased an arcade joystick of the sort used on a pac-man arcade game. This joystick has four microswitches for Up, Down, Left, and Right. To get the joystick to work, I needed something to convert those four inputs to a set of (step, direction) pulses for the G201 modules.

I created a relay board where each of the joystick microswitches operates a DPDT relay that will set the appropriate step and direction bits. When a joystick microswitch is pressed, the DPDT relay switches the step bit to a pulse generator and the direction bit to either 1 or 0.

The pulse generator for the joystick uses a simple 555 timer IC circuit with a pot to control how fast the motors will step. The joystick is entirely optional, and when it's not being used, the relays are all unengaged, and the step and direction bits are connected to the PC parallel port for computer control.