While I understand it takes a little longer to set up, I would setup each arm independently instead of doing the constraints and everything and THEN duplicating. The thing is that Carrara uses the ORIGINAL angles (in world space) instead of using the CURRENT angles (in local space.) So, when your 1st arm is 90deg from 0deg Y, then you duplicate and rotate the next arm to 30deg from that. When you move the second arm it goes 60deg from 0deg Y instead of 120deg from 0deg Y. (Does that make sense or hurt your brain as much as mine?) I would spend the extra time setting up each arm, instead of backtracking and fixing the offests. By-the-by, where you aware that if you haven't setup constraints for a arm yet, but add an IK chain 1st, the arm will be assigned constraints? They might just work out for you instead of setting them up then IK chaining it and have Carrara mess with your constraints. Just my 2 cents. :D Happy Rendering!