Hardware to Control and Drive Motors

Of course, motors on their own aren't very useful, the need to be powered and be provided with a control interface which will comunicate with the miling software on a PC.

The Motor Controller

The control circuitry itself is fairly simple but I decided to go to a pre-built solution that I found on eBay. This way, I do not have to worry as to whether I got the circuit right and would rather spend the time on other components of the project.

ALIEN - CNC SIMPLESTEP 4 AXIS STEPPER MOTOR DRIVER

The features of this device are:

• UK designed 4 Axis Bi-polar Micro stepping stepper motor driver
• The easiest to setup and use stepper driver on the market
• Permanent 1/8 microstepping on all 4 axis', that's 1600 steps per revolution----very smooth.
• Full access to unused pins for the use of limit switches, encoders, etc...
• Comes with full datasheet, and 2 year warranty
• Advanced Bi-Polar Pulse Width Modulating technology
• State of the Art cooling technology to achieve maximum efficiency without the need for fans
• Filtered and Buffered step and direction signals, to maximize signal clearity, and to protect your computer
• Works with 4,6, and 8 wire stepper motors rated above 1.8 amps / phase
• Suitable for stepper motors up to 500 oz. / in. torque
• No need for elaborate test equipment to setup up, Just wire up and you are ready to go, simply foolproof.
• Max. 30 VDC, 24 VDC @ 4.5 amps recommended.
• Fully modular, you can add up to 2 more axis' for a 6 axis monster
• Extremely small footprint, only 66 x 130 mm., fits in palm sized enclosures.
• Full datasheet available at http://www.aliencnc.com/datasheetaliencnc4axis.pdf

Now at $130, it was a little pricey. But I really liked the microstepping support and based on the picture, the board looks professional and does come with a 2 year warranty.

Powering the Motors

Powering the motors is pretty straightforward since the motors need a basic source of DC power. In the case of my motors, the top current per motor is <2 amp. And lots of hobbyists actually hack a power source from a used PC power supply. In my case, I did not have a used power supply handy so I yet turned around to eBay and purchased a power supply as part of another order to take advantage of their combined shipping discount. Only payed $13, so it was not a big expense.

I will likely combine the controller and power supply into a single enclosure and put a fan to keep it cool.