Bought one of these:
http://www.ebay.com/itm/1-4-Inch-Keyless-Drill-Bit-Chuck-Quick-Change-Adapter-Converter-Hex-Shank-0-3mm-/221421612023
The quality is excellent, it runs true and actually does close down to zero so it holds a #80 drill bit securely. it slips into my small powered screwdriver, just drilled about a hundred NBW casting holes with it :-)
Stan