Conclusion & Future Work

Manufacture and Assembly

We had several difficulties with the manufacture of the drink-pouring robot mainly because of the number of components involved (68 to be exact). The assembly was not rigid and there was visible deflection by the time all of the consumer-off-the-shelf components, bottle, and glass were added. This is mostly due to the acrylic material, which did not provide the rigidity we were seeking. During assembly, we also encountered issues with slippage. For one of the links in which a rod was press-fitted, the rod continued to slip on rotation despite the use of Loctite. This was due in part to the Laser-cutter, which gave us imprecise and inconsistent hole sizes and slanted through-holes. We decided to convert the shaft from a circular cross-section to a hexagonal cross-section along with their respective through-holes, since this would help with the slipping motion. Aspects of our design were also over-designed such that it was difficult to assemble some components, although we had originally aimed for ease of assembly. Bolts/screws were not easy to screw in, and there were too many nuts needed that were located in hard-to-reach places.

In future work, we would modify some or all components by using metal, machined parts, which should give us more precision in the manufacture of the holes, allow us to thread them for easier assembly, and use metals, which offer more rigidity. We would also modify the design to incorporate the hexagonal rods, since that drastically reduced slippage after we changed it in our assembly.

Potential Use of a Stepper Motor

We had hoped to use the encoder in the Pololu Motor we were given to read and control velocity; however, we were not able to get an accurate velocity reading from it. In future iterations, we would try to get the encoder to work so that we can implement a feedback loop to control the velocity of the linkages at a profile we desire. We would probably use a stepper motor for increased accuracy in future work.

Bottle Opener

We were not able to add a bottle opener to the final design due to time constraints. We hope to add a mechanism that will open the bottled beverage before it is poured in future work.