Quote - ...one axis of rotation would be at the center of a circle drawn at the inside top of the link below the link in question, the other at the inside bottom of the link in question itself.

I've been fiddling with this off and on, so far without any real understanding or, indeed, success. I've examined the chain you posted, Les, but although I know where I want my two joint centres to fall, and I can see the corresponding centres in your chain, I can't seem to work out what figures need to be plugged in to what channels in order to bring that about.

I'm trying to rig an existing chain, so I don't have any freedom regarding the geometry. I'd have had it done by now otherwise. :)