After the final CAD assembly model was complete, we began manufacturing the individual components. All linkages, housing pieces, the Geneva wheel, and the upper platform were laser cut from acrylic or wood. A motor support, two Bevel Gears, two Spur Gears, shaft and link couplings, the Geneva crank and Geneva mechanism base, structure supports, and a “blade” were all 3D printed from PLA plastic. 3D printing the gears was initially a worry, so they were printed at a finer resolution. They ended up meshing together nicely and worked well for our design. Additionally, we cut our main shafts from a ¼” diameter steel rod and connected them to our links with metal shaft couplers and collars. Several 5x11x4 mm ball bearings were used between rotating components to alleviate friction and to allow for smooth motion. The housing pieces were super-glued together with 3D printed “L-supports”, and the servo motor mount and Geneva mechanism base were super-glued to the inside of the housing. The shaft couplings were bolted to linkages, while all bearing connections were friction fit together.
One issue we ran into was the 1/8" acrylic sheets being sold out at the makerspace. Our design in CAD was used 1/8" sheets, but we were forced to use 1/4" sheets instead. This caused some issues with vertical alignment, since everything connected to the bottom sheet of our design was raised by 1/8" inch. We had to do some manual adjusting/sanding and print special pieces to make sure everything would still fit together.
We also ordered 1/4" bearings to fit our shaft, but they were lost in the mail. Due to this, we designed and printed ball bearing placeholders that met the OD and ID dimensions of the bearings and used them in the prototype.