At one time I didn't have a jointer in my shop. So I came up with a way to use
my oscillating spindle sander to put a smooth, straight edge on a board.
To do this, you need to make a special "offset" fence to clamp to the sander table.
As you can see in the drawings, the fence has a cutout that fits around the sanding
drum. Then to create the offset, I trimmed about 1/32" off of the "infeed" side
of the fence.
When you clamp the fence to the sander table, the outfeed edge should be flush
with the sanding drum. To use the "jointer," just hold the workpiece tightly against
the fence and slowly feed it across the drum.