I've been thinking about this for a very long time. My design requirements:
- Easy to get the PCB 'flat'
- Accurate and fast
- Automatic setting of home
- Jigged to make it super-easy to mill both sides without changing my X & Y zero points
|Click to enlarge|
Front-back alignment was very good (some issues during the test may have contributed to a less-than-perfect alignment).
I will document the enhancements I made. I added an anti-backlash feature - it is both easy and, based on my recent results - razor straight 0.012" traces, quite effective. I have a table/jig that makes flipping the PCB a zero-time exercise - without having to reset my X & Y home points!. I made a simple jig to nail homing my X and Y axis