A mechanic needed a work bench mounted grinder and went to the tool room to get one. None were available. He decided to construct a grinder by modifying an electric buffet wheel. He created a mount and attached the buffing motor to the bench. He removed the buffing wheel, installed a grinding wheel in its place and began constructing a guard.
Before the guard was finished he decided to test the grinder. He plugged it in and turned it on. As the wheel gained speed it reached a point where the centrifugal force caused the wheel to break apart. The wheel shattered into pieces, striking the mechanic with tremendous force. The mechanic died from multiple wounds to the chest and abdomen.
What went wrong?
Equipment must never be modified for use other than its intended purpose. Ensure that the grinding wheel is appropriate for the RPM rating of the motor’s spindle and ring test the wheel before it is installed. The mechanic used the grinder without the guard in place. A grinder must have a guard with a properly adjusted work rest and tongue guard and operators should stand to one side when starting any grinder. An operator must always wear eye protection when using a grinder.