CNC'ing PCB's - Aligning board using camera and fiducials.

[Mahonroy]

Hey guys, I have been lurking around a bit, and this is my first post.
After several failed attempts to find the correct information via google, I figured I would come here and ask.

Currently I am using cadsoft eagle to make PCB layouts, pcb-gcode to create the gcode files, and Mach3 to cut the boards.

I want to rig up a camera to the spindle, and have software locate a couple fiducials, and have the alignment corrected (either by having it alter my gcode, adjusting some rotation setting, etc. honestly I don't really know).

So my question is has anyone done anything like this? Can you point me in the right direction? Thanks and any help is greatly appreciated!

[IconicPCB]

Any correction with the camera is likely to be in the alignment of machine axes.

Have a look at G54 command on mach3. It will effectively allow for a touch off of the X,Y and Z axes against a ( camera ) reference.

You may have to include a subroutine inside Your CNC G code file.

[Fred27]

I'm sure I've seen similar stuff over on some pcb-gcode forum. If you're isolation routing the board though, why would you need to? Just mill the traces and route out the board without removing it from the mill.

I've now gone from isolation routing to etching so do need to line things up for drilling/routing. I just went with adding a camera to the mill and manually lining things up. It seems to work OK for the few boards I do.
http://0xfred.wordpress.com/2014/02/13/cnc-mill-alignment-camera-version-1-0/

[H.O]

And you can use G68 to rotate the X/Y plane a certain angle around a specific location. You'll need external software and interface that to Mach3 if you want it fully automatic but if you can live with the built in Video window and manually "finding" the fiducials you should be able to write a some macros and/or custom button scripts to set the correct offsets and calculate the rotation.