Manufacturing / Assembly

Manufacturing and Prototyping

To transition from the SolidWorks model to a prototype, we needed to find a good balance between material cost, ease of fabrication, and design precision. To avoid the slipping of circular bearings inside of our components, the team decided to use bushings, each with two flat outer edges to constrain rotation of the bushings when in use. To prevent any translational movement of the bushings on their corresponding shafts, we machined grooves into the steel shafts for snap rings on the outside edges of all of the bushings.

The machining process of the pinned joints involved cutting 3, 6mm, 12 inch shafts into 18, 1 ½ inch sections using a table saw in the UT Machine Shop. The edges of each piece were grinded down to remove any sharp edges or burrs left over from cutting. Next, 1/32 inch thick snap ring grooves were lathed down 0.08 inches, each 3/16 inches from each outside edge of the shaft.

Laser cut acrylic was used on the longest links of the four-bar slider linkages. Laser cutting was chosen for its ease of manufacturing and quick prototyping capabilities. Additionally, acrylic is available at very little cost in the UT MakerSpace. The team decided that machining all of the slider crank links would be time consuming and not cost effective. After cutting the links, the team discovered that laser cutting did not yield precise holes to press fit the bushings. To hold the bushings in place, the team cut snap ring grooves into all shafts that held the bushings to the acrylic links.

To connect the petals to the four-bar slider crank mechanisms, we 3D printed pin joint foundations to adhere to each petal using PLA. Additional parts printed using PLA include the hinges used to fold the inner petals, the slider, joints between linkages, and the U-joints which cause the inner petals to fold.