I have a 42 inch, two headed widebelt sander. Have had the machine for about ten years with no problems. Yesterday two boards shot out of the machine towards the operator side. I didn't see this happen, I just heard about it. To my knowledge this has never happened before.
They were sanding maple boards about 4 inches wide X 20 inches long. On a few occasions they apparently neglected to run the dust collector. There was a fair amount of sanding dust built up in the machine. When you ran your hand over the conveyor, it felt slippery like talc.
The machine has a feature to select its own initial starting position. You stick your material in and raise the bed with a lever. The bed will raise until it hits a desired pressure, then stop raising. At this point you hit an elevation button once that raises the head .2mm. Apparently the operator interpreted this to mean hit the button twice, so the cut was at .4mm.
The conveyor bed is in pretty good shape. The rubber feels a little smooth but the tread is almost 3/16 deep throughout.
What would cause this kind of kickback? My thinking is that the pressure was too great and the conveyor belt too slick. There was some slipping in the machine prior to this. Parts would get stuck in the middle and not continue to pass through. Does the rubber need to be freshened up somehow?
From contributor D:
That happens to us occasionally too. Usually just blowing the excess dust off the feed belt takes care of it. Forgetting to turn on the dust collector will clog the feed belt real quick and make it slick.