Shredding belts.

I always use a 4 ft long piece of 3/8" rod to check alignment. You bend a radius onto the rod to fit the drive pulley then fit the radius into the pulley and the straight part of the rod slides into the P/S pulley. If you keep the radius up against the drive pulley and slowly lower the straight end onto the P/S pulley you can easily see if there is any misalignment. Use a diameter of rod that fits snugly into the pulley so that it touches both sides of the "V" groove.