Belt sander through hole "desolderer"

So the idea for this is quite simple: you just sand away the underside and the parts are freed.

I've included two figures for some clarity. You allow the belt sander to pull the part along by friction, and you can control the rate of travel by adjusting friction, or by having some sort of indexing mechanism. A guide rail and guided carrier is used to control depth of "cut".

Figure 1: the basic idea

Figure 2: close up of side clamp. This would likely be made of brass or vespel. The guide into which it fitrs is likely high carbon steel, cast iron, or a tool steel (O-1).