4) Manufacturing and Assembly - Onion Cutter

The manufacturing of the assembly took a bit of preparation work. We ordered most of the parts from Amazon. A brief overview of the parts we ordered, were an RC car bevel gear set and a blade set. We realized after the first prototype, we needed a stronger motor to power the mechanism, so we had to upgrade from the 5 V servo to the 12 V motor. In the beginning phases of assembly, the main priority was preparing the links and the cutting board. We laser cut as many parts as possible because we wanted to get the parts prepared as fast as possible. We ended up printing eleven parts. This led to about 15 hours of cumulative printing time. The part preparation was over a four day process. 

Once the parts were made, the assembly phase began. The assembly process was by far the most tedious and frustrating part of the whole project. Surprisingly, one of the biggest obstacles we kept running into was finding bolts that were the right sizes for our gears, blade, and parts’ holes. If there is one thing we have learned from prototyping throughout this semester is that well-fitting joints are the foundation for a smooth moving mechanism. Compressing the bevel gears together without slippage was a big part of the success of the mechanism. Choosing to invest in snug fitting gears was a good design choice. Plastic gears would not have been able to achieve the gear efficiency that we executed. The total assembly of the onion cutter took about 25 hours. In order to get the links to move like the simulation we had to include lots of bearings, and mess with the joint tightness. We were very satisfied with the final product, it was a good start to a consumer product that could be advertised in those cheesy infomercials.