Okay weird one today, first time I've used my shapeoko in awhile, during milling I heard a little noise and saw something black in the sawdust, thought it was a piece of a knot or something (was working with pine), glad I looked instead of sucking it up, it was a set screw.
The weird thing is all the set screws are in place for the x/y1/y2/z axes. And it was literally in the channel the machine was cutting so Z/X are really the only likely options. It's right right size but I wonder if maybe it came out of the router, that or a set screw I'm not aware of? the 4 steppers each have two holes and all 8 holes have a set screw (of course one on each is engaged on the flat).
I'm looking around for a dewalt 611 parts breakdown next I guess. Weird.