This section focuses on The following is a discussion of the iterative evaluation of our manufacturing process. It begins with a discussion critique of our preliminary method and then transitions to our final process. Lastly we conclude with our lessons learned.
Preliminary Method
We simulated the pick and place mechanism using Creo Parametric. After slight fit adjustments and multiple evaluations, we converged on part geometries. Once finalized, our team set out to manufacture our first prototype.
We had decided to laser cut Our initial method involved laser cutting acetal delrin sheets (12"x12"x1/4") for our long, planar links and 3D print . 3D printing was reserved for parts with intricate geometries such as our custom gears (pictured below.)
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<CAPTION: PRINTED W/ IN FILL OF ?? AND RES ?? USING ?? PRINTER>
Upon inspection of the our laser cut links, we discovered visible heat damage and material expansion.
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Furthermore, due to the nature of laser cutting, the cut holes in our delrin had a were slightly angled edgeand lacked concentricity. This complicated our initial goal of press fitting bearings and rods into the material. While we did plan for this in our initial attempt by only cutting pilot holes, 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 design process did not allow for smooth and repeatable motion of our fully assembled system.
Final Method
Lessons Learned
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<INSERT GIF/VIDEO OF CADprocess 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