I just had a 10' plank fly back at me out of the wide belt sander. The boards all had to be pushed a bit, or else they stopped and the belt cut into them in one spot. I don't think I'm trying to take too much off at once. What are some machine adjustments I should be looking to change?
From contributor L:
Get out the setup book you got with the sander. It should have the spacing for all the settings. All adjustments are made in relationship to the contact roll. Bring your feed to parallel to the contact roll, set your hold-down rolls below the level of the contact drum. Set your platen just barely lower than the contact drum and parallel to it. All adjustments can be made with a block of wood and a feeler gage. Test your final setup with a board that you have drawn a wavy pencil line down the length of. Raise the bed until it just barely kisses the board. You will see the line smudged. Without changing anything, put the board through once on each edge of the conveyor. The look of the pencil line should be the same. Do it again with the platen lowered or installed. If your conveyor bed has any looseness, you will need to take care of that first. Ripples in the finish sanding can come from bad belt splices, conveyor feed system that has slack (look at the flex coupling), poor bearings in the conveyor belt rollers or contact drum, or out of balance in the sanding unit as a whole. As in most machine troubleshooting, start with the fixed part of the machine and work your way though the adjustable parts one at a time. There is always an obvious order if you stop and think about it for a minute.