Engineers often design carriages that move back and forth atop of a pair of parallel nonrotating shafts. These shafts must remain parallel or the carriage will wedge to a dead stop. So it is important that supports keep the shafts aligned. This can be a problem with traditional support blocks that keep the shaft locked into place with a cap screw located above and perpendicular to the shaft. With tradtional blocks, the shaft has to be inserted through the hole, a task that requires extra space on either end of the support. When the shafts, bushings, bearings, or carriage need maintenance, the shaft-support blocks must be removed and the alignment is lost. After servicing, the shaft has to be reinserted and the supports realigned, a time-consuming process