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Breaded Electronics / Embedded » Home made pick place SMT machine » 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:
2. tidy up some of the Mach 3 VB dialog screens and remove a few unused buttons
Software changes: