October 2, 2014
Use your Head Not Your Hammer!
By Tom Shelton
Many of our classroom discussion topics relate to problems in the field when attempting a precision shaft alignment of rotating equipment. One such topic is how to move a piece of equipment horizontally that does not have jack bolts already mounted on the base. The obvious answer is to mount a set of jack bolts to your equipment or use a Horizontal Alignment Tool Set with portable jack bolts. If neither option is possible then it is time to employ creative means to move your machine.
One thing is certain, DO NOT directly hit the motor or machine foot! This means don’t use a hammer or brass bar to hit the foot or machine directly. If the only means to move a machine is this type of force, use an intermediary device to soften the blow, otherwise, direct consequences will occur that may not be immediately evident.
When blunt force, such as a hammer blow, is applied to a motor or any part of a machine that contains bearings, the damage you inflict will cause premature failure. When a bearing receives a substantial blow, it can be possible to crack or at least leave pitting on the race where the roller and race are in contact. Other damage that can occur would be a cracked or bent motor frame. This is easy to do and hard to fix.
There are as many creative ways to move a motor as there mechanics moving motors. Be creative! Safe, and creative. I personally have used pry bars, port-a-powers, and made base modifications to keep from using a hammer. One example of base modification is to drill a ½” hole in the base approximately 1” from each foot of the movable machine. I then inserted a pinch bar in the hole to pry against with a small pry bar. This did not undermine the structural integrity of the base and the horizontal correction was easily completed. You are not usually trying to a lift a heavy weight, only slide it a few thousandths!
IF a hammer is your only option, use a piece of wood, a hammer handle, or brass bar and place it against the machine foot, then hit that instead of the machine. This is not the recommended method of moving a machine. USE YOUR IMAGINATION and BE SAFE.