The controller hardware is finished and now Im working on the software.

Diy Cnc Controller Code Onto An

Just put your g-code onto an SD card and follow the instructions on the screen.

So far I have tested it with ArtCam, Free Mill and Mesh Cam which can generate 4 axis g-code.

The kit allowed you to build various machines including a lathe and milling machine.

Obviously I wanted to automate the kit but I knew nothing about CNC or CAM software.

Most hobbyist CNC machines seem to use Mach3 software and a parallel.

I started with a Spider controller, a T6963 240 x 128 LCD and an SD card socket.

This setup allowed me to learn how to use the SD card and T6963 libraries.

The LCD display includes a 6x8 character set which gives you a 40 x 16 text display.

I did not bother with a fancier colour display since your not going to be spending much time looking at it except when you first set up the job.

Once I had the basics worked out (or at least I thought I had) I had a PCB made.

Diy Cnc Controller Drivers Which Are

This first prototype used Allegro A4988 stepper motor drivers which are supposed to be able to deliver up to 2A on each output.

The A4988 is a surface mount IC and really needs either heatsinks or a 4 layer PCB that uses the rear layer as a heatsink as shown in the datasheet to deliver the full 2A.

I found I could not get more than about 1.5A before the chips started shutting down from thermal overload.

I also discovered a problem with the way my hardware was scanning the buttons and limit switches.

When I designed the new controller I designed it so that the MCU IO.

This processor is dedicated to spindle speed control and attempts to maintain a constant cutting tool speed as the load changes.It also gave me extra analog IO pins to monitor air temperature, heatsink temperature and spindle motor current draw which can be used to detect a stalled motor.

The new MkII PCB ended up a bit bigger as a result of using much larger Toshiba TB6560 stepper drivers which are rated for 3.5A each and are available in a zip package which is much better suited to being mounted on a heatsink.

I used a tunnel heatsink which has cooling fins on the inside and two 40mm cooling fans, one at each end.

You may have noticed in the photos that I have added sockets for bluetooth and Xbee WiFly modules.

My intention was to allow wireless monitoring and g-code uploads.

So far the g-code uploads have been a problem as the g-code needs to be written to the SD card.

Unless the data is transfered at a painfully slow rate then chunks go missing.

Until I find a solution to the problem the wireless features are only good for wireless control and sending information such as job status.