Our PoV display uses a fixed-speed motor with a D-shaped shaft.  To create a platform to hold our LED arrays and circuit board, we clamped one flat aluminum plate and one aluminum plate with a semicircular hole together around the shaft and held them tightly closed with screws and lock nuts. We used small L-shaped connectors from an erector set to both attach a circular plastic base to the sheet metal and to mount LED posts to the circular base.  The mounting holes of the circuit board are designed to align with the mounting holes of the circular base.  The LED arrays are composed of 8 or 10 LEDs fed through small drilled holes in a tall, narrow strip of plexiglas with L-shaped connectors on the bottom for mounting, and reinforced at the top.  To provide our rotating system with power, we used a Mercotac® Rotary Electrical Connector mounted above the LED setup.  We press-fit it into a block of wood, which we screwed into a frame made of 80/20 extruded aluminum.  For stability, the frame is connected at the top, above the display, and at the motor mount on the bottom.  The motor mount is made of pine attached to the frame with sheet metal. Below are SolidWorks renderings showing the overall structure of our mechanical system, as well as an image of the aluminum motor mount at the bottom.

Side view of basic mechanical system design

Alternate view of mechanical system design

Close-up view of our motor mount