more panels

So now that the thermocouples have all been wired up, it is time to move on to the other forms of feedback that my cryo-friction rig will receive. Since we will be applying a biaxial load, we will need at least two load cells. We've decided to actually use three load cells (two horizontally and one vertically) so that we can be sure the normal load is consistent across the horizontal pistons (see here for schematic). In order to take the voltage signal from the load cell to the computer (and to display the current values), we need these type of card+meter panels. We salvaged a couple from old rigs but that plexiglass one is broken (and doesn't match...tacky!) and needs to be replaced.

There are companies that sell the perfect size of aluminum front plates with holes in all the right places, but they want ~$30 a pop for them. Money is a bit tight here in the ice research program, so I decided I would instead cut down my own aluminum panels from some other sheets we had on hand. First I cut down the length (though shown below in the milling machine, I actually used the saw) and then put the plate in the milling machine to make the square hole for the meter and small holes for screws. Those rounded edges on my square are the sign of a very poor cut job, but fortunately the placement of the meter will hide all the flaws

 

The front panel of the meter has tabs that are pushed through the holes around the square and the small electronic card is attached from behind with screws.

 

Here are the two new panels (left) sitting alongside the two old ones in the frame (the fourth meter will be for displacement). Now I just need to figure out the rest of the wiring and they will be good to go in the tower below my thermocouple meters.