In order to connect your computer to a set of stepper motor drivers, you will require an interface card. I have used the Ui Robot 2901-5a.

 

This card works off the parallel interface connection from your computer. This board is very reasonable in price and has good facilities, plus good documentation for setting it up with Mach3.

 

I purchased this board some time ago, before the release of Mach4 and Windows 10. Most new computers don’t have a parallel port any more. If you are yet to buy an interface card I would recommend purchasing a new USB type. They are a little more expensive, not only do they work a little faster, but most have a few extra inputs and outputs. These are required for running tool changers and speed sensors, which you may want in the future.

 

If you go the parallel route , you may need to put a second parallel card in  you pc to support more facilities at a later date.

 

The diagram on the left shows the typical wiring and use of the 25 pin parallel connector. This is what is contained in the Ui robot board. Other manufactures boards have slightly different arrangements. This board has an integrated PWM spindle circuit and gives a standard 10 volt analogue output line suitable for working the Little machine shop CNC motor interface board.