Tuesday, June 12, 2012

Today's Meeting

Today we had a meeting about bringing all the pieces together and getting our boat printed. Thanks to everybody who showed up to support the project even though it is a vacation week. Here are some of the key things we discussed/accomplished. I'm writing this from memory so if I get some of the details wrong (or forget something entirely) please correct me in the comment section.

We wrote up a calendar to give us a visual idea of what's coming up. We then filled in some dates for deliverables. We settled on an ambitious schedule to allow time for unexpected delays.


12 JUN
13 JUN
14 JUN
Extruder/Hot End Assembled
15 JUN
16 JUN
Obtain milk jugs from Whidby Island
17 JUN
18 JUN
Test printing with actual HDPE (hopefully waterproof)
19 JUN
20 JUN
21 JUN
Have an idea of warping and how to handle large prints
22 JUN
Decide on feasible boat design
23 JUN
24 JUN
25 JUN
26 JUN
27 JUN
28 JUN
29 JUN
Print boat

30 JUN
01 JUL
02 JUL
03 JUL
04 JUL
05 JUL

06 JUL

07 JUL
08 JUL
09 JUL
10 JUL
11 JUL
12 JUL
13 JUL
14 JUL
Milk Carton Derby!

An extruder design was discussed and should be assembled by this Thursday.

We sorted through 6 garbage bags of milk jugs and separated the clean ones from the ones that needed washing. It was a very unglamorous job but important nonetheless. Keep saving (and washing) your milk jugs because we're going to need them! We also weighed jugs and found that the average is about 67 grams. To put that in perspective if our final design weighs 100 pounds that's about 675 jugs.

We still don't have a final boat design, but that will be highly dependent on how many milk jugs we get and how skilled we become at printing in the first week of the quarter. The simplest design discussed is a flat bottomed boat with vertical walls that seats one paddler. The general consensus is that we will be thrilled with anything as long as it floats.

Lastly we were able to upload and run actual G-code on Big Red. The printer reads dimensions in inches so either our design work needs to be done in inches or we need to adjust scaling factors. We took a video of the print using a sharpie in place of an extruder. The video file is too large to upload here so you can find it at:

We have overcome several huge hurdles up to this point and only have a few left. Let's keep up the momentum and get this thing together in time for Seafair!

Happy printing.

Matt's add on...

To try ad make up for missing the meeting yesterday, I worked on HDPE printing. I tested various materials plastic cutting board, wood, screen door, tape etc. Wood worked ok but not well enough. So I decided to print directly onto milkjugs. I cut out about 8 squares of milk jug plastic, put a piece of parchment on top and ironed the stack until I had one thick sheet. It was super easy and the plastic fused nicely. I trimmed up the edges and printed on it. As you can see, the HDPE stuck really well. What was surprising is that the print was not completely fused to the build platform. It snapped right off with a good tug. Soon we'll see if this scales well. I'll be in today to work on extruder stuff (6/13).

end Matt's add on


  1. Bummer I missed the meeting! I'll have to check the blog more often. Kyle gave me all his boat design files before he left for summer, and I have been tinkering with boat designs too. Let me know the best way to get these to big red for printing. We have a few boats, the big 20 something foot Viking style canoe that is made in multiple pieces, an 8' canoe that can be printed as one piece in big red, and multiple paddle designs that could be good test pieces.
    On a kinda related subject I had an idea for laser dimensioning existing objects to quickly input the dimensions to cad software and reproduce using 3D printers. If anyone knows how the guts of solidworks works I would like to pick your brain.

    1. Aaron, sorry for the late reply! If you can make it to the meeting that I assume we're having on Monday, you can bring the files in on a USB, or something. Otherwise you can just email me the files (I'd prefer .sldprt, but .stl would work too), and I can convert them into the Big Red code.

      My email is pomeroyb(a)uw.edu

      Hopefully we will get some sort of blog post telling us what time to meet for printing tomorrow. HINT HINT MATT. ;)