I like the idea of a flush mounting link. In the olden days however, we were told the link had to be removable with a 'bill hook' (a hook on a pole). If this is not still a requirement - definitely worth some experimentation!

For our last version of the robot (which never got to compete) I used 'Detent Pins'
http://im01.itaiwantrade.com/8f79e43...12-360x360.JPG

Which pushed into a hole and connected two copper plates (with holes) together. The pins were 16mm diameter Stainless and not being the best conductor, still got quite hot! We were drawing 1200A peak though.

The pin locks in place until you pull the ring on the top which withdraws the two ball bearings and allows it to come out freely. The body sat inside a counterbored hole so only the little ring stuck out. Testing showed the ring would just be torn off without dislodging the pin in most cases. You could still remove the pin easy enough with a pair of pliars.

Si