As any woodworker knows, shop space is almost always at a premium. In order to have access to both the disc and belt functions on my combo sander, I had to come up with a creative solution. As you can see in the photo above, an oversized turntable was the answer.
The sander itself is mounted to the turntable with short lag screws. In order to keep the top from spinning while in use, I drilled two different holes for dedicated stops. With the sander positioned where I wanted it, I clamped the top platform in place. I then drilled a hole through the top into the base.
Through this hole, I insert a bolt with the threads cut off to lock the sander in place. The process is repeated with the sander in the other position.
For the top and bottom of the turntable, I cut out two large plywood discs on the band saw using a circle guide. With centers marked, I placed a lazy Susan bearing on the base and marked the location of the mounting holes. I then drilled an oversized access hole through the base. The hole should be slightly larger than the heads of the screws that you use to mount the bearing. The lazy Susan is secured to the base first, then screwed to the top through the access hole in the base. The weight of the sander holds the turntable to the bench.