|Project by jistincase||posted 08-19-2010 02:08 AM||3981 views||14 times favorited||10 comments|
I have always wanted a nice 12 inch disc sander but never could make myself spend the money to get one. I really enjoy making things out of bits and pieces and I had been saving a motor off an old vent system for over 15 years and finally decided to do something with it.
I found the design in a book that I had and followed it pretty close but made my own mods wherever I needed to. My one big problem was getting the disc to be balanced enough that it wouldn’t shake off the bench when in use. This also made me nervous as I kept thinking about it flying off and throwing a disc of wood through the shop at about 80 miles and hour. I tired using 3/4 cabinet grade plywood like it said but could not get it to run straight.
Finally I decided to try MDF of the same thickness. Since the pulley on the other wood was just screwed through the back I had to figure out a different way to attach it so the screws wouldn’t strip out and cause the run away wheel thing. I finally found a bigger pulley and I got some #10 round head machine screws and counter bore a hole so the head would be below the surface on the paper side.
This turned out to solve my balance problem but it was still a little skeptical about the durability of the MDF and if it might explode on me causing serious damage to me and the surroundings. I knew that I wanted something on the disc front other than just wood so that peeling the discs off would not keep tearing away the wood and causing rough spots on the disc that would cause uneven sanding.
To solve both my problems I went to a local salvage yard and found a piece of old conveyor belt that was about 3/16 in thick and hard rubber on one side. I sprayed contact cement on both pieces and put the cord side against the disc. Once it was set up I simply took a razor knife and trimmed it to the outside of the disc and voila. I solved 2 problems at the same time. Now the disc is a lot quieter than sanding against just a wooden disc and it covers the counter bored holes and gives me more peace of mind that the rubber will hold it together if the wood should some how fail at one of the holes.
-- If it doesn't work we will always wished it had.