Manufacturing
Find the SolidWorks CAD files here or .step files here for the design.
The frame is made of T-Slot PG20 extrusions as they are easy to assemble, provide ample mounting points, and provide excellent structural rigidity.
Using Adobe Illustrator, a vector pattern design with inspiration from Thingiverse was created. The design was placed on rectangular side panels in SolidWorks, and .dxf files were generated for laser cutting along with the gear platform, and electronics and servo mounting plates. The parts were cut from 1/8" black acrylic.
Aluminum brackets from Lynxmotion were purchased along with the servos. To lower costs and create a streamlined design, custom brackets (highlighted blue in below image) were modeled in addition to the aluminum ones. The custom brackets were 3D printed out of PETG filament on a Prusa MK3s.
Due to the complex geometry of the fingertips, traditional FDM printing did not yield the desired results without splitting the model into two parts. To resolve this issue a Stratasys PolyJet J750 at the Elko Engineering Garage was utilized. Using the state of the art printer rubber tips were added to the fingers to increase the coefficient of friction between the fingers and the gear plate, increasing stability and robustness of the design.
To increase aesthetics, a wifi-enabled RGB light bulb was placed in the center of the enclosure and powered from a 120V wall socket. Using the phone application that came with bulb allowed for easy colour coding and pattern creation. Wax paper was placed on the front panel to better diffuse the light due to the size of the engineering logo.