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Image of Schematic for A3979 Driver
Image of Schematic for A3979 Driver
Introduction:

A new driver based on the A3979 chip is in development. The A3979 is a tough chip to use since it needs ample and large contiguous copper surface area for heat dissipation. The great aspects of this driver chip is the integrated translator, the power for 2.5 amps per phase, and the ability to set to 1/16 microstepping. This driver requires less peripheral circuitry and may allow me to put three drivers on one board. I am also planning on making a small driver board if another 4th axis, or 4th motor is needed. Another reason this driver chip is used is that the cost is low and I don't need a microcontroller sending out PWM (pulse width modulation) to the vref of other non integrated drivers to get the 1/16 microstepping. The board and schematic will be available for download. I would recommend this project for the advanced level hobbyists.

Description:

Old News: I'm still in prototype stage with the electronics. The driver design has changed slightly to take advantage of more power to enable a wider variety of stepper motors. The electronics will now be based on the L297 and L6203 combo and will drive bi-polar stepping motors up to a whopping 4 amps per phase. The driver circuit will be designed to drive three axes without the need for a breakout board. That is to say, you will only need one driver board that the parallel port will connect and output to the three motors. Very simple.

The kit will be offered in two forms. the first configuration will be a kit that will require complete assembly (approximately 4 - 5 hours assembly). The second option will offer the electronics assembled.

Stay tuned during this timeframe that I will be developing this kit and I would like to hear any comments that you may have. If there is a specific product or component that you would like to see, or see develop, please provide feedback.

Related Tutorials
Step 23: Driver Part 4
This tutorial is dated, if you are considering a CNC for your personal use, we would highly recommend purchasing a kit that is very stable from our wide range of machines available. The driver is almost to a completion! We have installed all of the tiny components. Now to the big components. This is the logical process of putting together any circuit kit. The small components are difficult to insert if the larger components are installed already. Believe me, I've tried. Especially if there are jumper wires or resistors needed underneath chips and sockets.
Closeup allegro 3979 3 axis stepper motor driver board 3 and 4 Axis Stepper Motor Driver Board Based on the Allegro Chip
So, what exactly is a 3 and 4 axis stepping motor driver board. Actually, I am presenting the 3 axis stepping motor driver board in this article, but there is another much smaller board that will connect to this one that will provide an additional driver, making it useful for those wonderful 3D projects that use an indexer.
Step 20: Stepper Driver Part 1 - Resistors
This tutorial is dated, if you are considering a CNC for your personal use, we would highly recommend purchasing a kit that is very stable from our wide range of machines available. Well... here we are, finally getting started with the electronics portion of the video series. The entire structure of the CNC machine is complete with the exception of the router mount. We will get to that a little later. For now, we will start on the assembly of the HobbyCNC 3 axis chopper unipolar stepper driver.