The following is a discussion of the iterative evaluation of our manufacturing process. It begins with a critique of our preliminary method and then transitions to our final process. Lastly we conclude with our lessons learned.
Preliminary Method
Our initial method involved laser cutting acetal delrin sheets (12"x12"x1/4") for our long, planar links. 3D printing was reserved for parts with intricate geometries such as our custom gears.
<INSERT CUSTOM GEAR MODELS/ PICTURES>
<CAPTION: PRINTED W/ IN FILL OF ?? AND RES ?? USING ?? PRINTER>
Upon inspection of our laser cut links, we discovered visible heat damage and material expansion.
<INSERT BURNT LINKS>
Furthermore, the laser cut holes in our delrin were slightly angled and lacked concentricity. This complicated the press fits on our rods and bearings while adding additional alignment issues. We did expect this complication; however our method for expanding those holes with a drill press did not yield desired results. The accumulated error from this process prevented assembly of our first prototype.
Final Method
Upon reevaluation, we concluded that CNC milling is the best method to machine our parts. Not only is the CNC mill more accurate and precise than the laser cutter, but it also did not leave burn scars or expand our material. Moreover, the precision offered by the CNC mill enabled us to press fit our rods and bearings securely.
Lessons Learned
Preliminary Method: Laser Cutting
Final Method: CNC Milling