Manufacturing and Assembly Group 14

Base and Platform:

The back and base plates were designed with box joinery such that they may be easily assembled using wood glue. The back plate has a curved top to model the motion pathway the cups will travel during their pouring period. Two support plates are vertical but perpendicular to the back plate to balance the weight of the mechanism. The bottom plate holds the system in place to reduce the play the system has to ensure better pouring and catching. The base and platform can be seen in the following image:

Gears and Links: 

The driven gears were laser-cut, so their central hole fit a 5mm nut.  This nut was press-fit into the gear and tightened to the link such that friction between gear and link would allow them to turn together.  To facilitate this assembly, the shaft used was a 5mm bolt.  

The lower links were assembled into a pin joint using a cut shaft and a 3D-printed bracket. Initially, we designed the upper joints to be assembled using a similar shaft. However, in order to reduce play in the mechanism, we 3d printed pins that would act as the shaft for the upper joints.  This was successful, and the amount of play in our final design was small enough to allow our mechanics to provide the repeatable motion desired.

These brackets were far better at axially constraining the links than a press-fit or shaft collar alternative.  With the motion adequately tight and with low friction, we were able to 3-D print the cups used to transfer contents back and forth.

Cups:

The cups were 3D printed due to their relatively complex geometry.  This would also allow us to quickly and easily iterate between designs.  The final design we chose is shown below.