Update: this coupler has started to fail. See details on the update post, as well as a new model. Here are the links to Thingiverse and Shapeways, but be aware the current 3D printed plastic material ("White Strong Flexible") is not proven for long-term use.
Update: here's a video of it in action with the drill adapter clamped directly onto a Hario Slim Burr Grinder. Actually works pretty well as is, so I will put the piece on Thingiverse soon. Lots of refinements planned though.
A while back I had a brief flirtation with the idea of DIY Kitchenaid attachments, but never really got going on the project. Then recently, jeffkobi posted a nice Instructable on how to attach a Kyocera manual burr coffee grinder to your Kitchenaid and it rekindled my interest (not least because I own the same model burr grinder).
I really liked jeffkobi's idea of using an inexpensive Milescraft 90 degree drill adapter as the intermediary between the mixer and the grinder. So I've been trying to develop some simple 3D printable pieces to make it easier to couple the drill adapter to the Kitchenaid attachment hub. This is a work in progress and is going to take at least one more iteration to refine, but I'm pretty happy with how it looks so far, so here's some teasers.