Wednesday, June 13, 2012

Week 2: the flume arises

And week 2 it is!  A lot happening here, the flume is starting to become something recognizable.  Here's a few shots of the pieces I've constructed so far, not much on their own, but they'll look impressive soon.

The base plate, the clamps are holding the glass plate to the plastic sheet until the glue sets.  The spores will settle on the glass.

Moose had some concerns my original design for the connector box being able to supprt the weight of the water and pipes.  So he had the great idea to turn my "box" into a "elbow" (or a 90 degree connector) which solves the problem of the weight support but still leaves me with a circular cross-section of water that need to be rectangular.  To solve that problem, I cut a rectangle out of the pipe cap, and am going to fit a few plastic pieces to form box that reduces the flow to the shape I need for the shear flume.

This is the piece that fits over the base place, and will connect to the connector box. I'm basically just gluing two plastic bars to a sheet of glass.
The biggest holdup so far is the carriage assembly, the thing that the motor moves back and forth.  This has proved both more difficult and more expensive than expected. Right now I plan to use the motor to spin a threaded pipe, with will force a block to move back and forth. But I bought a $50 carriage on McMaster (the key piece of the assembly) that didn't really move smoothly at all, meaning the threaded rod with probably get stuck rather than slip through.  I'm going to make some adjustments tomorrow and try to make this carriage work, but I might need to find another way.

The carriage assembly is also way more costly than I expected.  It seems like each assembly will run over $100, way more than I anticipated (I guessed $20), and even at that price, it's not all that great.  But then I realized that I am completely automating my data collection process, and that this is a pretty awesome and creative way to do it, and when it works it will be so worth it. I had to manually count spores under a microscope as fast as I could in my PhD, and that to avoid that again is worth a little time, energy, and money.  

In any case, it's definitely a good thing that I got more than I asked for initially.  Thanks everyone!  Your generosity has covered my cost underestimate.

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