I'm going to be building a prototype Watt Balance for possible implementation in the Physics 307/308 labs. I think this would be a nifty Garage project for anyone that wants to work on it with me.
The Watt Balance technology is going to replace "Le Grande Kilogram" as the mass standard. It will instead tie mass standards to quantum and electromagnetic standards. The folks at NIST have designed an inexpensive, LEGO based Watt balance that is accessible to students. We're going to build a variation on this theme.
Here's a video on the basic operation of the Watt Balance: https://www.youtube.com/watch?v=bMYvVgsotIk
Here's a paper on the specific build design I'm looking at: http://arxiv.org/abs/1412.1699
Let me know if you are interested! Brett