Wanted to use my Centrotec bits with my Milwaukee Drill. Made an adapter. There are 3 parts to print. I started by printing all in PETG but ultimately printed the main part in stainless steel via Shapeways here. The other 2 parts (the washer and housing) can be plastic I'm pretty sure. One caveat to this build is that you need to sacrifice a Milwaukee 1/4" Hex Attachment for parts. I ordered a spare one off eBay so I could keep my other one intact. Once you print the main adapter part in stainless steel it will need some filing/sanding on the inside and outside to have a snug fit on the drill body.
Youtube Video showing assembly:
The author marked this model as their own original creation.