CNC

Using a CNC milling machine

last updated: 07/04/20

Introduction

I bought a new toy :). A STEPCRAFT-2/D.840 construction kit to built a CNC milling machine. The mechanical part of the construction was no problem due to the good assembly instructions.

I didn't want to use an old PC with parallel port and I love Arduino, so the first choice was GRBL. And finally I had seen the MaXYposi project with the MaXYpulti :) in the German Make magazine.

After a successful assembly of the mechanical parts I wanted to connect the GRBL MaXYposi board with the stepper driver board included with the kit, and ran into understanding problems, first because of being a CNC Newbie and second due to a lack of information in the STEPCRAFT manuals. I know that stepper driver have a DIR, STEP and ENABLE signal, but what should I do with an error signal, and only one XYZ limit signal, GRBL needing three of them. And why do I need relays, and are we dealing with negative or positive logic?

The following pages document my struggling :).
Makey

GRBLing a Stepcraft milling machine

Calculating the feed rates

Naturally I want to use open source software. I use Incscape or FreeCAD to draw my projects. The next step was the milling process itself. I found interesting information on bCNC, written in python and tried this software with success :)

Milling with bCNC

Using the mill as plotter and laser engraver will be documented here:

Plotting, lasering, and milling with Inkscape

An a next goal will be to mill directly from FreeCAD if that is possible :).

Milling with FreeCAD