I, too, am concerned about the speed. I sent them a message this morning asking about the RPM. The Guinevere has been around for a long time. I don't think they had DC motors like we have today, and speed control for induction motors is a no-go. You can control the speed on universal motors, but you lose torque at slow speeds. Modern DC motors had full torque across the speed range. Now, if you could figure out how to hook the sanding accessories to a DC motor from a treadmill that would work well. I can build a speed control for one of these easily and cheap.