Larry PMed me about how I made my 80" edge belt sander so I'm going to start a thread about how I made it.
Here are some pics. I actually made 2 of them, 1 for me and 1 for my father in law. I made both of them out of stuff I had around so they were free except for the sanding belts. I used a 1hp 1725 RPM motor and used a v belt pulley to attach a 4" drum to. I put the pulley at the end of the shaft and screwed through the pulley into the drum. The drum is 2 3" schedule 80 PVC couplers glued together and there are wood plugs in each end. I suppose that you could use a solid wood drum. On the top of the drum I made a recess in the drum to hold a bearing. There is an arm that has a short shaft on that fits into the bearing to support the top of the drum. It is important to have this or the drum will flex when sanding and the belt will shoot up and off the machine. I know this now after hours of wondering why the belt tracked when running, then shooting off the second I sanded anything. So thats the power end. For the sanding "backing plate" I used a piece of large C channel for one of the sanders and the other I used a piece of steel plate and welded angle iron on the back of the plate for stiffness. For the free spinning drum I used a roller from a section roller track that I got from a junk yard. You could use a short piece of steel tube with bearings that slip in each end and a long bolt as an axle. One end of the roller has a tracking adjustment. Its simple, just a nut welded on the axle and a bolt that threads into it. By turning the bolt the axle moves in a slot and tracks the belt. There is a quick release mechanism to change the belts. Its not too complicated. The free spinning drum is mounted on a bracket and part of that bracket slides into tubing on the backing plate. There is a cam mechanism and a spring that operate it. The spring will hold the drum "out" and tension the belt. To take the belt off just move the cam lever and it pulls the drum in and takes the tension off the belt. There is a slot so the cam lever will catch in to hold the lever while the belt is being changed. That is the bulk of the mechanics. I know they aren't pretty but for free you can't beat them. Let me know if you have specific questions about how things work.Originally Posted by larry merlau