Changes 20110908

Change completed

This change is:

1. simply to attempt to improve calibration of each PCB to improve placement accuracy.

When this machine was first run, I was positioning the gantry at the edge of the PCB that was the PCB origin per the PCB CAD package and setting that as relative X0, Y0

It soon became clear that guillotining can be quite variable from the PCB manufacturer

The next solution was to align to a mounting hole.  All my PCB's have 3mm mount holes 4mm in from each corner.  So I then started to aligning to these as X4 Y4 etc but still some placement issues.  I am assuming the layers can be misaligned at the PCB factory.

This change iteration is to change the Excel generator & Mach 3 VB diaogs so we still do a coarse alignment to the mount hole but then a fine alignment to a nominated PCB pad per PCB.

Hardware changes: NONE

Software changes:

  • Excel generator:
    • Add space per sheet to record calibration pad refdes & X,Y offset from origin to center of the pad
    • Add initialisation of GCode vars 2100-2101 to pass above X Y vars to Mach 3 via generated GCode
  • Mach 3 VB dialog changes:
    • In main dialog add buttons per rotation to:
      • move camera to calibration pad from PCB origin
      • set pcb origin offset from the current camera position per the calibration pad PCB origin offset

2. tidy up some of the Mach 3 VB dialog screens and remove a few unused buttons

Software changes:

  • Mach 3 VB dialog changes:
    • Move Head up down buttons to Head calibeation dialog
    • When a 'Set head' here button is clcked, retract the head at the same time
    • Remove 'Set Head to G56 / G57' buttons (was used *poorly* to calibrate heads prior to the upward looking camera