I'm building a scale to measure the weight of a keg (~5 gal, 28kg full). The plan is to measure the weight as beer is poured and therefore estimate the remaining. Currently we're using a flow meter, but if a pour is very foamy, the volume that comes out doesn't match well to the volume of beer. Plus, we get compounding errors where each erroneous pour adds to the overall error of what's left in the keg. If we simply weighed it continuously, we'd get a much better measure of remaining mass.
Anyways, I've been reading a lot and found a 30kg load cell that should do the trick. However, I have no clue on how to build the physical platform. It looks like the preferred way to do this is to mount a platform (wood?) both above and below in a "Z" configuration so that it torques and deforms the load cell when weight is applied.
Has anyone built anything like that? Can I get something 3d printed? Also, am I better of going with several strain gauges and wiring that to an amp?
Basically, I'm looking for advice on how to build a scale for the 5-30kg range that's accurate to roughly 30g, which would be ~ 1oz. Should I just buy a digital bathroom scale and take it apart?