I bought this kit from screwfix http://www.screwfix.com/p/wago-basic...5pcs/48808#_=p I haven't used them on anything CNC yet, but for solid core domestic wiring they are very good and quick. For multi strand wires I crimped an uninsulated ferrule on to get the wire in to the block. That was fiddly, but better than choc blocks.

Rob