Update: Bevy Bot - a Partial Success?

Well, here we are again and this time I have a partial success - and pictures.

Let's start off with some pics from the rebuild.  Some of you may have never seen a peltier device so here's a picture.  I circled it in pink for you.  It's actually a device that's about 1.5"x1.5" that has 127 couples of dissimilar materials (bismuth and something else).  What those materials are, changes how well the device works.  The cheap versions that you find on the auction sites really are cheap, not just in a financial sense.  In my picture here, you see a commercial grade unit.  It's so much better than the others that I burned up.


Anyway, I installed in a 6 gallon cooler.  It's a misconception that you want to put the "bigger" heatsink outside.  Or is it?  Which would you say is bigger?  The one on the inside is spread out more, but the one that I put on the outside is more dense.  It has more actual aluminum.  So it's not actually bigger in size, but it is bigger in volume.




In the end though, they still weren't enough to get things cold.  So I made them better.  In this iteration I added some copper pipes to the heatsinks and am pumping water through them.  The inside isn't finished yet (none of it is actually "finished").  I'm still waiting on my new pumps, which should be here next week.  I had a pump inside, but it died.

Without the pipes I had fans on the heatsinks, and that didn't work very well at all.  I couldn't cool the hot side enough to do any good.  Now at 1 amp, cooling starts.  This photo was taken at 2.2 amps.  That's ice covering the fins.  They are reading at around 20 degrees Fahrenheit.  I think I could get them colder.  Is that cold enough to cool my bevies?  I'm not sure.  I was able to get water down to 46 degrees Fahrenheit, in an hour, before the pump died, so I think so.  With the fan on I have only been able to get water down to about 50 degrees, it keeps the unit from freezing over, but that's about it.
 

So now what?  I'm still waiting on parts, but I still need to work on distributing the cold on the inside, and then I can start perfecting it.  Because, this whole contraption is going to be a robot, I don't have to worry about carrying this thing around.  That's good, because as it sits right now, it weighs about 100 pounds, bevies included.