Week 2: The robot moves!

The last two days were a huge success! I managed to get a fully functioning carriage move back and forth, powered from a stepper motor using a code from an Arduino!  I'd like to say it was my ingenuity that solved my carriage problems, but most of the credit really goes to the lubrication properties of WD40.

This shows the carriage assembly in the coolers that I'll be using for the experiments.

 

 And, a video of the action:

Unfortunately this drama with the carriage has put me behind schedule a bit.  The flume is nearly assembled, next week will involve assembling the flume, figuring out how to take pictures with a webcam using an arduino, and final programming for the arduino code (not the most exciting or photogenic of activities).  I don't think I'll actually get to calibrating and testing the setup until week 4. 

On the plus side, I've now figured out how to make and bought all of the necessary components for all of the different aspects of this project.  Just in time too, I've nearly reached the end of the budget!

In other news, there's great low tides next week!  I plan on going on collecting field trip, and finding some nice algae to use for the first few algae pressings.

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.

Week 1: motor controls

Wow, eventful first week!  I spent more time than I would have liked getting settled, ordering final parts, and meeting various people, but I still managed to make some progress.

Arduino is ridiculously easy to use!  I sat down with the parts and software on Thursday morning, and by the end of the day, I was able to connect the arduino to the motor and use a code to make the motor spin!  Yay!

Sure, this isn't on the forefront of technology or anything, but it's still pretty damn amazing to me that I can write some random, arbitrary characters on a computer, push a button, and get a motor to do something.

It gets better though, because Moose let me borrow his Arduino LCD shield (a chip that connects to and sits on top of the arduino, giving you a simple display and several buttons).  But the end of Friday, I had programmed a neat little menu into the LCD display that let me control the motor completely through the Arduino.

And that was about it for real progress this week, though honestly, I didn't expect to get a nearly finished code in arduino so quickly, so this is actually more than I expected to get done.

I'm making a page with my current planned schedule, in case you want to follow along and know what's ahead.  Finally, I'll end with a sprinkle of few pictures from the ferry ride here, and the field trip on Wednesday.

Damn, I wouldn't mind living in that house.

Friday Harbor Laboratories, as seen from the ferry as we pull into the port.

Seaweeds! If you're not looking forward to many glamour shots of seaweeds, you're probably on the wrong blog.

A giant Pisaster seastar! And bigger than my hand!  Special exception here due to it's remarkable size, don't expect many pictures of disgusting animals.

Week 1

Ok! All packed and ready to go to Friday Harbor tomorrow morning, via bus, plane, bus, and ferry.  I'm posting this in fear of being one of those annoying bloggers who writes about every little thing that happens ("Now in the Terminal", "Now boarding the plane", "Now exiting the plane!").  Trust me, you'll get none of that.  I am pretty new to this blogging thing though, so if I start doing it wrong, feel free to let me know.

I'll aim for a twice-a-week posting schedule to keep everyone updated, without being overtly annoying. This week, I'm ready to hit the ground running! I'm flying in during a low tide week, so appropriately have some tentative field trips planned for this Wednesday and Thursday with Dr. Patrick Martone, a professor from University of British Columbia and coralline algae expert.  Also, he used to be my labmate and is a good part of the reason I study corallines now. He's one of the two professors I'll be working with this summer.

Diagrams!

Special treat today, for all of you eager to see what the hell this contraption looks like.  I sketched out a simple hand-drawn diagram.

As you can see, I'm no artist, but hopefully you get the idea.  There are four pieces, a base on which the spores settle, and then three attached pieces which when added to the base create a shear flume.  Water builds up in the gravity flume, creating pressure.  The water then transfers through the holding box, whose purpose is to connect the vertical 2" pipe to a thin narrow shear channel.  The cover fits over the base, creating a thin narrow opening through which water flows to create shear.


I've now ordered the raw materials to construct each of these components.  Yay! Turns out custom-cut glass isn't so hard to find on the internets, even found a place in Washington to supply the glass pieces, so it shouldn't take them too long to ship to Friday Harbor.