Left Side View of the miniSpinner  

The Latch holds the back in place.  You release the latch to hinge the back down when you want to change bobbins.    

The 12 Volt Power Jack is where you plug in 12 volt power from the AC adapter (included) or the automobile 12 volt power cord (also included).  You can also run the miniSpinner from a portable battery pack.  Because the miniSpinner uses so little power, a small portable jump-start battery will run it all day.  

That black finned thingy is a Heat Sink that conducts heat away from the motor, which is directly beneath it.  The flyer acts like a fan to blow air across the heat sink, cooling the motor very effectively.  The heat sink probably isn't really necessary; early prototypes didn't have one and the motor rarely even got warm.  But, better to be conservative, so the production miniSpinners have heat sinks.  

The Motor Sheave (whorl to spinning-wheel types) drives the polyurethane belt that drives the flyer.

You can also see the large shielded ball bearing at the orifice (right) end of the flyer.  The bobbin (left) end of the flyer runs in a self-aligning plastic bearing for the minimum amount of friction.  

The miniSpinner does not need oiling as the plastic bearing is self-lubricating, and the ball bearing is lubricated for life.