Community PCB Mill Project (using the Parallax SX microprocessor), ca.2005

by D. Daniel McGlothin
22 July 2005, version 1.2 [ 2286 views ]

Copyright © 2005 by D. Daniel McGlothin, All rights reserved.

There once was suggested on the Parallax support forum The Sandbox that a group effort might be put forth to craft an SX controlled 2.5 or 3 axis PCB mill.

The idea caught my attention, and I lurked on the thread for a while. I entered active participation when the subject of the communications protocol between the PC-based application and the SX-based motion controller came up. This participation took the form of volunteering to provide an Introduction to G-Codes and related subjects. I also experimented a bit with a Basic Stamp 2 interpreting a quite limited G-Code syntax for the purpose of seeing how much memory required for doing interpolated motion.

In the event that I actually do build an instance of this mill, I'll document that effort here too.

My contributions to the project.

Introduction to G-Codes
 
A brief introduction to the various buzzwords related to G-Code processing, especially as related to PCB milling is presented. The Gerber files for the Basic Stamp 1 OEM are used to provide concrete examples of some of the concepts.
Basic Stamp G-Code Interpreter
 
As a proof of concept, the Basic Stamp 2 implementation of a 3-axis, 1-spindle, limited G-Code interpreter is described.

An annotated list of references that I find interesting and germane to this project.

Parallax
 
SX
 
SX/B
 
Links to Parallax, and to their SX microcontroller and the SX/B compiler. This is the central core of the motion processor of this PCB Mill project.
Interactive
 
Printable
 
The thread in the Parallax The Sandbox support forum that documents the development of the idea of the SX Community PCB Mill.
$200 CNC
 
PCB alignment
 
David McNab shows how he built a CNC drill for small PCBs in the sub $200 range. He also describes a simple method of assuring proper alignment of drill holes with the PCB traces/pads.
Target 3001
 
A PCB CAD package that claims to do PCB milling output. Also has a front-panel layout tool that emits a DXF. Free limited version.
Machn Manuals
 
Manual for Mach1, Mach2, & Mach3 software. Provides broad-ranging coverage of machining and G-Codes in the context of using the product.
TurboCNC Manual
 
Manual for TurboCNC by DAK Engineering. Provides coverage of machining and G-Codes in the context of using the product.
Drillcon 100
 
Nicholas Redgrave describes his buildup of a CNC Drill. His controller reads the Excellon drill files directly.
CNC Drill
 
Derek Hawkins photodocuments his recently completed CNC drill.