Originally Posted by
stewi
I tend to agree with the majority, that vision system may be an overkill.
Most of the commercial machines use board conveyors, which either require mechanical board alignment (troublesome) or optical (fiducial) board recognition.
If we insert the board manually in the machine, we’ll likely use pins in the board mounting holes and get the boards pretty well pre-aligned.
Larger components, except fine pitch, can be aligned with mechanical jaws at the head or in an external alignment station.
Smaller than nozzle components could use a special shaped nozzle, assuming that we get component pick up fairly accurate.
What I would recommend:
Mount a USB microscope to the placement head.
Determine camera to nozzle offset by placing a small blob of silly putty in the placement area.
Lower z axis with nozzle into the silly putty to leave a print.
Zero out X and Y.
Jog the camera over to the nozzle print in the silly putty.
Write down X and Y offset.
If your entire placement program can run with an offset, than you can watch on the monitor pick up and placement. Else, you can modify your program in Excel, adding or subtracting the offset value in pick up and placement.
Make corrections, as required for pick and placements and run your batch of boards.
For inspection after placement, you can run your board program with the camera offset again.