Matt Rogge testing the 3D printed HDPE boat












WOOF group has spent the last two months researching. engineering, extruding, printing, and dumpster diving for the greater good. WOOF submitted the first 3D printed milk jug boat into the Seafair Milk Carton Derby. Not a simple task, they hacked a 4′ x8′ plasma cutter, slapped a homemade extruder on, and dealt with 2% shrinkage, to produce a beautiful boat. The boat weight is 40 lbs (~250 1 gallon Milk jugs) supports 150lbs, yet cuts through the water like a canoeyak.


After spending weeks in a dumpster, sorting milk jugs and cleaning them.  Scrapblasters was gracious enough to do some controlled small batch shredding to maintain clean mix of only #2 HDPE milk jug plastic. WOOF was finally ready to print. With the hopper feeding beautifully, the first test print was a success.


HDPE extruder














Scaling up the process had its own trials, but the WOOF team has a diverse group who balance out problem solving with skill and ingenuity. They worked with materials that were cheap, effective, and readily available. This technology has great application in many third world countries, and islands where plastic processing is limited or, the materials must be shipped off island. However the greatest contribution is not the plastic being reused, but the land and water masses it reclaims turning them from dumping sites to useable spaces and ecosystems.

More about their printing process is available on their Blog  (or click WOOf @ UW) on the right.


Long night of day two printing the boat.


There was some confusion when WOOF entered the Derby about what class they were in. They had come to race, but it wasn’t clear whether or not they qualified. No one knew what to think of a boat printed out instead of the traditional strapping of cartons to a structure.  WOOF was placed in a Group category due to some confusion, and the boat required some explaining.

Yes this is made of milk jugs. It weight 40+ lbs which is ~ 250 1 gallon milk jugs. In fact this is the only boats that is 99% Milk jugs. 1% weird stuff that fell into the hopper. Thankfully, a commitee decision by  Kyle and Andrew (from the Seafair) placed WOOF back in it’s original racing category. After receiving the notice that their racing status had changed,  Matt Rogge and Adam Commons loaded the boat in the water 5 minutes before the race.


Matt waits at the Starting line-up in the 14+ Heat
Seafair 2012









Matt keeps up with the everyone and starts to break away from the pack.











Matt Placed 2nd in the 14+ heat


Denny’s Seafair Milk Carton Derby Rules & Regulations

A. The derby is divided into several age and vessel categories. A boat can be used for only one age and entry classification. And only once within that age and entry classification.
B. Only the following types of cartons may be used to provide flotation: one-half gallon, one gallon milk or juice cartons or one gallon plastic milk or juice jugs.
C. A minimum of 50 one-half gallon milk cartons is required for each entry except in the Commercial category where a minimum of 100 one-half gallon cartons is required.
D. Please arrive at least one hour ahead of the event you plan to enter. Entries must be classified and inspected prior to registration. Registration closes 30 minutes prior to each event.
E. All participants must sign a waiver/release form and turn it in on-site at registration if they have not pre-registered online. If you are a participant under the age of 18, your parent or guardian is required to sign the form.
F. No one under the age of 8 is allowed on an entry unless accompanied by an adult
G. Each participant must wear a U.S. Coast guard approved life jacket while in the water, and must have them at time of inspection. Ski belts are not acceptable.
H. Showboat awards are based on creative use of milk cartons, originality and workmanship. The use of creative materials, design and methods of movement is encouraged.
I. Entry must have a pole or minimum 18” x 18” vertical flat surface to which an entry number can be attached on the right side (shore side).
J. Entrants are expected to transport their entry away from the site, or disassemble it and put it in the garbage dumpster provided down by the boat launch area. Your help in keeping the area clean is appreciated.
K. Crafts must be of home-made construction and primary flotation dependent upon milk cartons. Waxing, shellacking or covering the hulls with material such as plastic, packing tape, lamination or metal is not allowed. You may use chicken wire or plastic mesh.
L. Do not enclose the bottom of the vessel, leave it open so inspectors can examine your boat for compliance to derby guidelines.
M. Fixed oars are not allowed in the Open or Commercial categories.
N. No engines or motors of any kind are allowed. Propulsion power or any other kind of stored energy (i.e.: tank filled with compressed air or water) is prohibited. Sails will be for decoration only and not for power. Human power only.
O. Any propeller or mechanical device must be covered by a protective enclosure. This includes chains, belts, paddle wheels, side wheels, sprockets, etc.
P. Contestants will begin the race in their boats at the starting line indicated by the starting buoys. Any boat crossing the starting line early may be disqualified. Boats must remain in their own lanes. Judges may disqualify vessels impeding the progress of others.
Q. Boats must stay inside the designated course.
R. Vessels must remain in the same configuration for all events.
S. Nothing is to be thrown or released from boats while in the water. Decorations must be firmly attached. Violation is an automatic disqualification.
T. Prizes in all other categories are based on speed and will be awarded to the first entrant who crossed the finish line.
U. Participants must be present to win prizes.
V. Inspectors will classify each boat prior to registration and will inspect each vessel to make sure that it fits within the rules and safety guidelines outlined above. Racing style boats will be entered into the Racing Category only.
W. Any boat not built according to Seafair Milk Carton Derby Rules may be disqualified.
X. Decisions of the committee are final.


P.S. The University of Washington issued the following press release which includes a short slide show.

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18 Comments on WOOF Rocks the Boat

  1. […] I know, you thought 3D printed shoes were crazy, or even 3D printed chairs, but how about this 3D printed boat? […]

  2. […] is awesome! The folks over at WOOF have 3D printed a boat from reclaimed milk jugs. From O3DP: WOOF group has spent the last two months researching. engineering, extruding, printing, and […]

  3. […] to this outline at the University of Washington, the task included hacking a large plasma cutter to take a […]

  4. […] new UW student club, Washington Open Object Fabricators (or WOOF), built the boat as its inaugural project. They spent the last two months researching, engineering, […]

  5. […] innovative new 3D printing projects, and this is no exception. This may be the first functional 3D printed boat (any objection?). It was made with a 3D printer hacked together from a 4′ x 8′ plasma […]

  6. […] Printed Boat Posted on July 27, 2012 by Ed I tip my hat (were I wearing one) to the University of Washington mechanical engineering students who entered Denny’s 42nd Annual Seafair Milk Carton Derby with a 3-D printed raft. This […]

  7. […] was raced at the annual Milk Carton Derby at Green Lake in Seattle. The new UW student club, Washington Open Object Fabricators (or WOOF), built the boat as its inaugural project. They spent the last two months researching, engineering, […]

  8. John @ Machined Parts says:

    3d Printing will be the ‘standard’ of parts and manufacturing but the price point just isn’t there yet. Just like any other skill, learn the new way of doing things but always know how to do things the old fashioned way. Just in case the new 3D Printer breaks down. What’s next?

  9. The Material Web 1.0 and Creative Capitalism | FormFonts 3D Models says:

    […] Washington Open Objects Fabricators Club – WOOF […]

  10. Patrik D'haeseleer says:

    Pushing the boundaries a bit on the “must be of home-made construction” rule, but if you’re organizing a milk jug racing competition, you’d better be open to some creativity, right?

    • ganter says:

      We actually checked with the Seafair Pirates rules committee as soon as WOOF become truly interested (so as not to waste everyone’s time). The rules committee was very open to this idea BUT they insisted we follow the rules for materials, etc. Overall, we think this was a really fun idea to show off 3D printing.

  11. Anonymous says:

    3D Printed Boat. I can only imagine how long will it be for a printed cruise ship or an aircraft carrier to become a reality.

    No more Made In XXXXX thats for sure. lol

  12. Vern says:

    Just thinking of mating the uni-chassis of current automobile to a 3D designed car~

  13. Vern says:

    Awesome feat.

  14. Buy and Sell 3D ... - Used 3d Printers For Sale says:

    […] jug plastic taken from dumpsters.   The WOOF group had much more than making a boat in mind. WOOF Rocks the Boat (Open3DP), “This technology has great application in many third world countries and islands […]

  15. […] WOOF entered a 3D printed boat (made from recycled milk jugs, of course) for the first time the Milk Carton Derby last year. We made a tiny boat that managed to come in second. More on that can be seen here: […]

  16. dave says:

    this could totally kill kayak and canoe companies if you can get the boat a little lighter. professional kayak hulls are made using a process that actually spins a mold cavity to create the hollow hull shape. very tricky. very expensive. but also very light weight. any ideas on how you’re gonna cut down the weight? what about a 3d print oar too?

    • bowman says:

      The oar WOOF printed was too floppy, higher resolution is necessary to make the smaller things light and structural

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