I just finished most of my upgrade yesterday. I still have yet to hook up the z-limit switch wire to the controller.

I have the router version and found that, once together, my alignment was way off. I happened to have just resurfaced my spoiler the day before which was handy. However, I basically had to take it all apart again. This is when I noticed that I could unbolt the router with everything else left in place. By extending the router to its lowest Z position, all four bolts securing it to the "spindle mounting plate" were accessible from the back of the desktop. So, I removed the router, then re-uninstalled the Spindle Mounting Plate. At this point, I was able to use my square to the left (from the front) edge of the Carriage Plate and adjust the true-ness of it. I could then re-mount the Spindle Mounting Plate; but I wasn't able to adjust it as the screws for that adjustment were blocked. It was off by a tiny bit (which means that some day I will take it apart and re-adjust) but for now I just pressed on. Then I could mount the router and use the square on that when tightning. All-in-all, the adjustments could have been done as I went; but I was following the instructions as printed...

About the Z Limit Switch... I had to take it off and re-mount. I went to Lowes to get a longer M3x40 screw and ran it through from the back for the right hole (from the front). I used this to help get the position correct and then tighten down the mounting screw through the left hole (from the front). Then I had to remove the screw that I put in from the back because its head got in the way of another part. If I could have found a m3x40 set screw, I would have left it in (from the back) to continue to support the position of the sensor.

Note to designers: If you made the Z Limit Switch printed circuit board a bit longer (I would swag it at about 3/4") and made the second support screw further to the right so we could get to it from the front, it would make this a bit easier and increase the clearance between it and the backlash spring when it was at top-Z. Just a thought.