Here's a good example: a drill press being used as a jointer.
The idea is that you notch a piece of hardwood or plywood for the fence to fit around the sanding drum. The trick is to take an extra 1/64" or 1/32" off the width of the infeed side of the fence. Then position the fence with the outfeed side even with the sanding drum, and start jointing.
Woodsmith editor Terry Strohman shows you how it's done in this video.