Very interesting that I never thought about only using 2 or 3 cam locks. If you only knew how many times I've wrestled with all 6. Would have been easy to remove them to get 2, 3, or 6. So various screw patterns would fit. It's a whole new world!
Both my D1-6 collet chucks have three pins - not a backing plate, built like that. Two seems fine for a drive plate, but given the cam lock is suppose to be be the slightest of interference fits if I could call it that, three or six is probably better for anything else.
It's just like lug nuts on the 1 ton, so much quicker changing out the snowies with just 2.Very interesting that I never thought about only using 2 or 3 cam locks. If you only knew how many times I've wrestled with all 6. Would have been easy to remove them to get 2, 3, or 6. So various screw patterns would fit. It's a whole new world!