Comments that I have heard in all types of industry are “We always have the time or money to do the repair over, but never time or money to do it right”.  Many times when equipment fails there is an incredible rush to get the machine back online due to some production requirement. This usually leads to repairs that are inadequate or incomplete.  It is important to remember that as long as your lock is on the machine it is not going to go back into service until you remove that lock. It could take as little as an additional 30 minutes to allow the machine to be repaired completely, but instead, the job is rushed and a few weeks or a couple of months later the same machine is being repaired for the same reasons again.

Production controls the purse strings that is a given, but generally, product quality and maintenance cost can be better controlled by allowing for a complete repair, not a partial fix. A couple of examples that come to mind are belt-driven machines. Many repair techs simply roll V-belts on and off for removal or installation. Have you ever noticed a V-belt running upside down? In most cases, it is due to the cords in the backing of the belt being broken. This is usually caused by rolling the belts on or off the sheave.  If “power band belts” are used the cost of those belts is usually higher than the sheaves that the belts are running on. It is a paradox that brand new belts will be installed on worn-out sheaves.

When the sheaves are replaced most of the sheaves are affixed to the shaft with a taper lock hub. How many people use an indicator to ensure that the sheaves are square to the shaft and not just tighten the hub with an impact wrench?  There are others examples, but hopefully, this drives the point home.  Repairs need to be done in a timely fashion in cooperation with production to minimize downtime and reduce any effects on quality.

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, by Gary James CRL