Oops

Went to a customer last week that had made a very big oops. Generally speaking, wide belt sanders are pretty hard to mechanically damage. When things do go wrong, and damage occurs, there is usually a conglomeration of events that had to happen in a specific order to cause the negative end result.

One big exception to this is height adjustment. While it is always safe to open the machine, care must be taken when closing. Especially after some kind of evolution has taken place such as maintenance, cleaning, or testing. A great habit to form is to check the inside of the machine before closing it, especially if the feed belt is not running.

Some machines have a sensing roller or rollers in the front of the machine that prevent the machine from automatically closing to the preset height unless the feed belt travels a certain distance to ensure that there is no part in the machine. When a part, or tool is placed into the machine like when calibration is checked these sensing rollers are taken out of the equation. The machine will close to whatever value is in the controller as soon as the machine is switched on.

This will crush the tool or part and push the sanding head up. Damage can range from a chunk taken out of a rubber roll, to wrecking the graphite layer of a platen, to bending of a segmented pad. Worst case scenario is that the head frame itself and the frame it is bolted to get bent and/or cracked.

This is what unfortunately happened to my customer last week. Very expensive lesson.