First step add a ceramic platen. This was a $0.55 4" wide tile I found at local ReStore. I used algle grinder to score a line to shorten it to fit. Then I used the belt to round over the leading and trailing edge corners. I put 2 screws into the existing platen as a stop. Then some E6000. I only have 80 grit for this thing, lots and lots of 80 grit But it was sufficient to square off the file guide I just made as well.
Ceramic Tile as platen, belt moved out of the way
File Guide
Ceramic Tile as platen, belt moved out of the way
File Guide