These neat little 3 jaw chucks are only 48 mm in diameter, made from steel with a scroll mechanism they are quick to operate and are tightened with two small tommy bars.
 
Adapted to fit Meccano Large Axles 5/16" dia or the standard Meccano Axles (please choose option below)
 
I do reccomend the large axle option if you want to do any serious work, the standard Meccano axle version would only be useful for very light work