My four jaw chuck has to be hoisted up with a block and tackle and takes 20 minutes to install. I sometimes need to drill a hole in the end of a roundthat is off center. The latest is a 1/2 fine thread in the end of a 1" round that is 1/4" off center. I use this for a cam action by screwing in a cam follower. I found that a .3425" shim in one jaw of the three jaw chuck is just about right. One of the guys asked if it could be figured mathematically. I'm WAY too stupid to do that. Can it be done?