For anyone with double drum sanders, such as the General International 25" sander I have, the drum adjustments can be confusing: set both drum to same height and then lower the outside (discharge drum) a bit lower than the infeed, with paper installed. There is an easier method: set both drums to same height, then install the heavier paper on the first drum (for me 120 grit), and lighter paper on second (150 grit for me). Run a piece of wood through so it touches out on the infeed roller, stop the sander, and lower the second drum an index mark or two. Run another piece of wood through to see if both drum touch out. If not, lower the second drum another index mark or two. For my General, the outfeed roller touched out at 6 index marks lower than the front. Went through several dozen passes of white oak, came out perfect, with no loading of the sandpaper or burning.