Kinetic Flower

 

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Petals

The petals are made of 0.015" brass sheets that were bent to conform to a 0.031" brass rib. We chose brass for its sleek look and color, and were really pleased with the softer patina it picked up as we worked with it. All the brass parts were waterjet cut in Olin's machine shop. Each petal connects to a Power HD 1501 servo, which rests in a custom brass housing. The housing is hinged to the base plate and connected to the center mechanism, which is described below. This allows the petal to move both left and right, as actuated by the servo, and back and forth, as actuated by the center mechanism.

 

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Central Mechanism

The central mechanism tilts the petals inward and out through the motion of a single central servo. The servo is attached to a plate below the center hexagon. When the servo turns clockwise, the flower closes. Turn it counterclockwise and the flower opens. Each linkage radiating outward from the center servo is made up of four identical brass links, so that the mechanism has five degrees of freedom.  M3 metric bolts are used as the connectors with washers as spacers to cut down on binding in the mechanism.  We used lock nuts to control the amount of friction between the links.

 

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The petal design in this render was abandoned due to high material cost.
System Design and Process

The final design that we settled on was one that allowed for the six petals to be independently driven by our high torque servos.  The center aperture was connected to a seventh servo that would control the opening and closing of the entire flower sculpture.

The servos were controlled using a pic micro-controller which can be tethered via USB to a nearby computer. We created a python GUI with sliding scales that allows the user to control both the center mechanism and the petals, which we grouped into threes for ease of use. The python code also maps certain key positions (petals left, center open, etc.) to keystrokes.

The team spent a lot of time in SolidWorks because we would only have one shot at fabrication due to time and budget constraints. Every part went through at least two iterations before we decided on our final design. In the end, it really paid off, since the only modification we had to make post-fabrication was the addition of a small mechanical stop in the center mechanism.