First thing Monday morning I took my slightly improved CAD file for the 42 hour print to FreeZone and got that started.  After lunch I took a trip to the engineering building to test out my temperature theory.  After explaining my theory to the student intern technician in my broken Portuguese (he was very patient with me), he helped me set up the prints.  First, we ran my test print at 150ºC.  Since the print was so small (which I had done intentionally), we sat and watched what happened.  The print generally went as expected, and when it was finished, the support material chipped off pretty nicely.  Next we ran the same file, but at 190ºC for comparison.  As we watched it run, we could see plastic sticking to the hot nozzle and dragging around as well as plastic dripping out from the nozzle when it wasn’t supposed to.  This resulted in some tangled up plastic and a very messy print– with impossible to remove support material.  It seems that the nozzle temperature was indeed the problem and caused the support material to stick to my long print.

For much of the rest of the week, I started designing little add-ons for my case that would hold parts of the electronics inside.  Because these parts were so small, there were some iterations of trial and error, but since the prints were an hour or less that was okay (although a little ironic when the printer took longer to heat up than to actually run the print).  I also spent some time working with Juliane and Guilherme at PUCRS on the electronics hardware (I really only contributed to soldering and delivering new parts to them; thankfully they handle all of the coding).

After lunch Wednesday, my new case was finally finished!  And it looked great!  All of the support material came off without damaging the case.  However, when I tested the LED ring it didn’t quite fit because one part of the circle had printed with a flat zone (instead of the continuous curve of the circle).  Unfortunately, CriaLab was hosting presentations all of Thursday so I was unable to fix the problem until Friday.  After a little Dremel sanding, the LED fit nice and snuggly and looked all snazzy contrasting the black plastic.  I would call this print a success!

Friday night after dinner I ended up spending an hour or two talking to one of the girls living at the Casa who is from Italy.  Since she doesn’t speak a lot of English, I took the opportunity to attempt my Portuguese.  While I’m sure it was very rough, Crizia was very patient and by the end of the conversation I was feeling pretty good about myself that I was able to hold a conversation in (mostly) Portuguese.

Saturday afternoon Allie, Latané, and I visited the Mercado Publico, which was not exactly what I expected.  The Mercado Publico is inside an old building and is predominantly a food market, with meat and fish shops, fruit and vegetable stands, nut shops, and chimarrão (the Brazilian term for yerba mate) stores.  After wandering around the mercado, we then left the building and wandered down a street full of shops (mostly clothing).  This street probably fit the stereotype of Brazil more than anywhere else we have seen: busy with a variety of racial/ethnic backgrounds and a bigger range of socioeconomic classes than what we normally see at PUCRS, an expensive private university.

Mercado Publico

That night Allie and I went to a restaurant that my coworker Guiseppe has been suggesting since my first week (and every Monday I come to work and he asks, “So did you go to Nono Ludovico?”).  In the USA, many people are familiar with the serving style at Brazilian steakhouses in which waiters come around with meat and you choose if you would like a slice added to your plate.  I learned that this style of serving is called rodízio and is not limited to meat here.  This restaurant was a fancy pizza rodízio, and boy was the pizza good.  I don’t even want to know how many calories I consumed, but it was certainly worth it.  From 5 cheese to bacon and garlic to brie and honey to key lime pie, both the savory and sweet pizzas were delicious.  If only we had gone earlier in the trip, then we could go back!