I do agree with your sentiments about publishing early to ‘play the system’ at its own game though. Good post.

(Discovered via MAKE magazine email alert.)

Idea 1: Why not add in an accelerometer instead? The problem with switches is that the top of the bed is covered with a flat glass plate. An accelerometer could be added at the bottom of the board. You can still do the same 3 point validation, but what you would do is have the head hit the glass top at three different points, and you could detect the hit based upon a vibration on the accelerometer. Also, if you have more than one Z axis motor, you could easily set it up to auto-level (or more accurately auto coplanar) the bed to the X-Y plane of the head.

Idea 3/Idea 7: I think you are close in Idea 3, (I actually thought about this (Idea 3) a few months ago, but found it not feasable because the 3D printed plastic is too soft when it is printed until it cools down, attempting to machine it with a CNC end mill will end up with goop). However, I just thought of a better idea (which is inspired by your ideas 3/7): What about 3D printer + Laser cutter combo?? Both will work with almost zero lateral forces (another problem of CNC + 3D printer combo), and the moving head mechanism is pretty much compatible between the two devices. I would be interested in working on this hybrid, as it has possibilities!!

consider publishing via http://ip.com/

There is a small cost, but the likeliness that your publication is accepted as prior art seems to be increased.

Kind regards,
Thomas