[Swansea Hackspace] An old PC with parallel printer port?

[Justin Mitchell]

On Tue, 2014-09-16 at 09:15 +0100, Graham Owens wrote:


> Modern drive electronics are fine, but I would not be very happy
> running it without a host PC for the time being until we could talk
> over the safety aspects of doing so.
> Unlike the 3d printer that will make some noise to complain about
> someone getting their hand in the wrong place, the mill can do some
> serious damage - so the ability to preview, view the cuts as they are
> happening and most importantly emergency stopping need to be dealt
> with first if we were to move away from linuxcnc.

It would still need a host pc, but not one thats timing critical, and
with just a usb port. like we run the 3d printer, it feeds one command
at a time to the driver board.

I was just looking at the electronics used to run the shapeoko open
source cnc mill.

A couple of ways to do it:
GAUPS (or equivalent) shield + Arduino Uno + GRBL firmware
http://store.amberspyglass.co.uk/gaups-1-0-arduino-compatible-stepper-shield-kit-50v.html
https://github.com/grbl/grbl
and then a front end like:
http://zapmaker.org/projects/grbl-controller-3-0/

or

a standard reprap type controller board (eg RAMPS), with the Marlin
firmware, and a frontend that translates the gcode slightly. 
http://reprap.org/wiki/CNCGcodeController


Both types would use the DRV8825 stepper drivers, which can drive upto
45v, and 2.2A per phase (if given enough cooling, 1.5A without)

What do you currently drive the steppers with ?

p.s. a big red 'stop' button may also be a worthy addition