This is a front view of the same machine. The table rides on two shafts (you can see the bolts holding the ends of the shaft under the table). The reciprocating motion comes from an arm connected to an eccentric on the motor's shaft. The machine is powered by a 177 rpm gearmotor salvaged from a copier.
The inverted palm sander on the right has been modified to hold a 1 inch wide piece of neoprene on the business end which holds strips of adhesive backed abrasives. I use this to clean up stubborn scratches at the plunge cut. The red box at the top of the machine holds pre-cut strips of adhesive backed sandpaper for this machine.