Remember, there must be a cylindrical shaft rotating in a cylindrical hole. Anything else will be a problem. if part of the pivot is protruding too far out of the jewel hole, it might mean that either the lower or upper jewel was pressed in too far and the shoulder of the staff is rubbing on the bottom of the jewel. Jeweling tools (Seitz) have micrometer stops on them to properly depth the jewels in the bridge and pilar holes. The balance staff can introduce two additional problems due to cap jewels pushing on the pivots. To troubleshoot, remove the gears and add them back in one at a time starting with the 2nd wheel. Rotate the assembly with a small sewing needle or similar tool and add the gears back into the train in sequence (3rd, 4th, 5th). When there is resistance, that will be where the problem lies.