Putting It All Together


So here is a picture of it all put together. The tuning of the final circuit was fairly trivial
however I had a few problems with the packaging and electrode connections.

I designed the packaging with some very tight tolerances originally (.75mm wall thickness, .1mm
clearances between parts) because I had plans of machining the case and was relying on the tight
clearances to keep the top from wobbling when a cup was placed ont it. Once I had to fallback on the
3D printer for the package I had to increase the clearances. Doing this canceled the effect on the 4
veins and notches that I had put into the package and caused a lot of wobble in the top. The only fix
I could come up with was the 3 pieces of sponge that can be seen in the picture above. The do a good job
of helping with the wobble.

The electrode connections were also troublesome because I had to make the connector out of the thinnest
wire possible in order to prevent the wire from supporting any of the weight of the cup when it was placed
on the device. Even using extremeley thin wire had an effect on the top so I had to be methodical about
how I positioned the wires when putting the top on. Also because the wire was so thin it would snap at the
solder joints constantly. A little hot glue helped but did not entireley solve the problem.