To ease fabrication, given the materials and fabrication methods available, the initial CAD model was modified as shown below:
Fabrication of Links
The links, guide arm and carriage were additively manufactured (with Fused Deposition Modelling - FDM). This greatly simplified the task of fabricating the complex geometry of the guide arms in addition to reducing machining time required. PLA was the fabrication material of choice as it is less susceptible to warping compared to other materials available for fabricating with FDM. Also, it provided enough strength and smoothness for the sliding of the rollers on the guide arms.
Fabrication of Gears
The driver and driven gears transmitting motion from the motor were also fabricated with FDM. The gears were designed on geargenerator.com and exported to STL format for printing. Dimensions were chosen to amplify the motor's torque output (MA>1).
Base Plate and Stand
The base plate was fabricated using laser cutting while the stands were wade of wooden blocks.
Assembly
Mounting hubs, set screws and additively-manufactured retention rings were used to achieve tight-fits between the shafts and bearings.
The final assembly is shown below:
