Updated adapter between a KitchenAid stand mixer attachment hub and a Milescraft 90 degree drill adapter. There are two sets of changes: 1) To the square piece that fits in the KitchenAid hub. I expanded from 0.45 to 0.47"; this takes the slop out of the fit. (I believe the hub is designed as 12 mm.) I also chamfered the ends of the piece so that it's easier to get it into place. 2) To the cylinder that holds the Milescraft adapter bit. Multiple changes to try to prevent it from eventually wearing out and slipping. I added a 3rd set screw. I made the walls thicker. I added flat faces to the interior of the bit hole to try to match the bit shape more closely. Posts on previous versions: http://absurdlycertain.blogspot.com/2012/07/update-2-diy-hario-conical-burr-grinder.htmlThere are three holes at tap size #29 designed for 8-32 set screws (3/16" length is good). McMaster 94355A182 is fine, for which you'll want hex key 7122A15. For most 3D print materials, you're better off driving the set screws directly into the piece rather than trying to tap the piece first. That keeps the fit tighter. The last time I had this printed at Shapeways, the screw hole didn't stay clean and clear. If this happens, make sure to clear them out by driving the screws all the way through and cleaning a bit to make sure the screws are biting the Milescraft bit tightly.