I have been on the lookout for a good universal mounting system for my MPCNC, and was also contemplating designing one, though my design skills are pretty rudimentary. On 12/30/15, user HicWic uploaded a new universal mount to thingiverse. Check it out: http://www.thingiverse.com/thing:1234989.
I printed the main receiver, and then used the models provided to make compatible versions of my DW660 mount, laser mount, foam cutter mount, and pen holder. I printed everything in PLA, since I get the best dimensional accuracy with it over ABS. Unfortunately, this mounting system requires VERY close tolerances (a good thing from a tool rigidity point of view) that my 3d printer just could not turn out. I kept the PLA version of the receiver, but reprinted everything else in ABS. With some judicious use of a swiss file and some acetone, I now have some very nice, smooth-fitting, mounts for all my tools.
I will upload my mounts to thingiverse pretty soon, but I’m sure I’m not the only person who had been wishing for a universal mounting system. With a little manual adjusting (or maybe a really really accurate printer), this is a pretty good system.