Reply by Lazyman

Washing machine motors might not have enough HP for a disc sander of a decent size. They are probably in the 1/3-1/2 HP range. I would think that 3/4 to 1 HP would be best. You might be able to use some belts and pulleys to slow it down so it has less of a tendency to stall when you put a a large piece of wood against it. Not sure what the RPM is so you would want to make sure that stepping it down so that it doesn’t stall doesn’t make it turn so slowly that it isn’t very useful.

One thing that a large disc sander is handy for is flattening faces that you going to glue together like when making a segmented bowl for example ( if you don’t have a thickness sander). Your belt/spindle sander will handle most of the other types of applications like sanding to a line for example.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.