Undanate
CEILING-MOUNT CRANE.  2010.  Design & Construction: Carl Pisaturo. 
Materials: machined aluminum, delrin, stainless steel, brass; DC gearmotors, bal bearings, epoxy castings, phosphor bronze cable & brushes, custom electronics.  40" rotation radius, 12' vertical travel,  power-conducting cables.
UNDANATE  (wave propelled swimmer) Kinetic Sculpture with Lighting.  2010   Design & Construction: Carl Pisaturo. 
Materials: machined polycarbonate, aluminum, delrin, stainless steel; soldered brass tubing; LEDs, DC gearmotor, ball bearings, gears, epoxy castings, custom electronics, etc.  24" long,  16" wingspan.
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An attempt to convey the beauty of one of nature's nicest tricks: propulsion through a fluid by the undulation of a membrane.   

Undulation can be thought of as a wave staying still while the creature creating it moves. 

Undulating membranes are "superset" functional relatives of bird wings and lateral fins of fish, and as such illustrate the action more clearly.

Compare to the man-made analog: the propeller.  Whereas undulation is a bidirectional linear process, propellers, being capable of continuous rotation, are the unidirectional rotational version.
the cuttlefish uses undulation to maneuver with impressive speed and precision
Implementation of the sculpture is based on circular cams.  There are two stacks of 24 delrin cams, locked in opposite rotation by gears. All this is driven by a single maxon gearmotor.  Each cam drives a free-pivoting brass arm which has a red LED at the end.  An early 4 cam proof of concept rig is shown at left.

To achieve the illusion of wave propulsion, the sculpture is carried through the air on a pair of cables by a slowly rotating ceiling-mounted crane.  As the sculpture passes overhead, the internally lit cam system becomes visible through the frosted skin.  The motions and shadows of the cams form an interesting visual counterpoint to the undulating wing structure.

Undanate's machinery is simple, smooth-running and robust, and intended for long term maintenance-free operation.
Undanate Details
Crane Details
works of  Carl C Pisaturo