Press the front roller on a hard surface. The roller will push in and lock in a retracted position. Slip the old belt of and put the new belt on. Then, take a hammer and smack the side (circular cross section) of the front roller. This will release the catch and spring the roller back into it's operating position. Then turn it on and adjust the tracking with the adjustment dial on the side.
Try Sears service department. UPDATED INFORMATION: * http://www.bobvila.com/BBS/_Craftsman_Belt_Sander_Model_31511720-Tools-1-T963.html
There is almost always a small lever on the side of the roller carriage. This needs to be pulled out to release tension on the roller and allow belt changes.
You move the lever outward which loosens tension on the roller and makes the belt slack.
sears.com
I found a manual for Craftsman 113.225900, which is as close as I can get. It is an older belt and disc sander.
Try managemylife.com and click on "manuals".
The oiling instructions are on the data plate
In any belt sander you clip the dustbag over the exhaust port and empty it when full. - Saves a lot of dust from flying around.
I need the belt diagram
1/2x33 inch belt, manual calls for a 1/2 x32.60
The instruction tag on my 315.22600 says "2 drops of SAE 20oil in oiler at right side of front pulley"
Check the manual it shows a diagram of the belt routing. If you don't have your manual you can get it here: http://www.managemyhome.com/mmh/lis_pdf/OWNM/L0805481.pdf
A wide belt sander has many different uses when it comes to needing to sand something. A belt sander can be used to sand down piece of wood that you need to get a nice curve on.
Take and set the sander on end with the cord down. The, with both hands, push the front roller towards the boc that sits between the rollers. You will hear a click. That takes the tension off the belt. Remove the old 3x21 belt with a new one. Now, while this sound strange it is what the manual suggests, take a large screwdriver and place it between the black front roller bracket and the square housing that sits between the two rollers and pry so you are pushing the pront roller back into position. You will hear another click and the spring will reposition the front roller and put tension back on the belt. Then, run the sander and turn the knob on the other side of the sander until the belt tracks correctly.
it is in a technical workshop
A Dewalt belt sander can be found at a variety of retailers on the web. One looking for a Dewalt belt sander could explore looking on Amazon, Home Depot, or the Dewalt main website.