Yukon Educational Theater approached YuKonstruct earlier this year to ask if the makerspace and Chris Lloyd, who designed the cardboard airplane costumes, would be interested in building the effigy for Burning Away the Winter Blues. Of course we jumped at the chance to build an epic effigy!

Burning Away the Winter Blues is an annual celebration in Whitehorse where Yukoners mark the arrival of spring by burning all their worries away with a giant effigy that represents the winter and cold.

Inspired by PenfoldPlant's Giant Papercraft Trojan Horse, we decided to build a giant yeti snow monster, laser cut out of cardboard.

Icycle Sport donated 30 bicycle boxes which we cut down and used to make all 292 carboard pieces. The internal skeleton was made out of wood salvaged from a renovation project.

Step 1: Design

Chris designed a snow monster, the Yeti, to symbolize all our winter worries and blues. The 3D model was created in Autodesk’s MeshMixer and then 123D Make was used to turn it into a series of panels that could be cut out on the laser cutter. The model was exported to SketchUp where Chris drew the plans for an internal skeleton made of 2x2s to support the cardboard skin. All the software used is free and also available on YuKonstruct’s computers.

Some design considerations:

For insurance/liability reasons, YET limited the height of the effigy (when thrown in the fire) to 8 feet. This is conveniently the same size as the inside of Chris' cargo van, making transportation to the start of the procession easier.
The torch-lit procession that carries the effigy to the bonfire is a 2km long parade on an icy path along the Yukon River. The effigy needed to be both light enough to pull/carry and sturdy enough to hold up along the bumpy ride. It also had to be easy to throw the effigy into the fire when it reached its final destination.
As the effigy was going to be burned at the Robert Service Campground, we were only allowed to use materials that would be burned away or could be safely swept up after the fire (no plastics or other synthetic materials).

Notes on using the software to get the desired outcome:

It seems impossible to get 123D Make to generate panels symmetrically, but we really wanted it symmetrical. We were able to accomplish a symmetrical design by first using 123 Make to convert the model into panels and then exporting the panelized model. In SketchUp, we split the model in half and mirrored a duplicate, before opening it in 123D Make again. If you import a highly panelized, low poly model, 123D Make will draw the panel edges where expected.
The settings we used on 123D Make were based on the rivet settings, and customized to accommodate wider, deeper tabs and holes large enough to wire things by hand.

Yeti_Final_LP_STL.stl
Download View in 3D

Step 2: Small Scale Model

Before committing to building the giant effigy, we tested the design by assembling a small scale model out of cardstock.

While putting together all the pieces twice might not seem very appealing, having a small maquette is extreme helpful when you are assembling the full sized version.

Our team of volunteers were able to refer back to the small model while making the effigy, and found it much easier to search for a particular piece on the model than on the computer screen. Since 123D Make doesn't number panel pieces with any logic that we could easily discern, figuring out which piece goes where is one of the most time consuming parts of the assembly.

We didn't glue all the seams on the small scale model and left it in 4 parts (legs, torso and head, and arms) so multiple volunteers could work with sections of the model at the same time.

Step 3: Constructing the Cart and Frame

The frame was built out of salvaged 2x2s and scrap plywood. The parts were cut based on the SketchUp design and screwed together.

Our solution to transporting the effigy during the procession was to mount him on a cart. We used a Yardworks Dumping Garden Cart as the base, as it was the only thing Canadian Tire had in stock. Something with larger wheels and a wider wheel base would likely have been better, but we used what we could find in a limited amount of time.

We reinforced the cart base with scrap plywood, added a piece of plywood to widen the top and then mounted two pieces of pvc pipe to the top with simple L brackets.

The 2x2 skeleton legs were trimmed so they would slide into the pipes, making it relatively easy to put the effigy on the cart and remove it. When it came time to be tossed into the fire, the effigy was lifted off the cart without any fussing with screws or other hardware.

Step 4: Cutting the Cardboard

Icycle Sport was one of the sponsors for Burning Away the Winter Blues and donated 30 bicycle boxes for the effigy. The boxes were cut into 31" x 20" sheets to fit into YuKonstruct's laser cutter.

While 123D Make is a great free program, it's far from perfect and we had to do a bit of tweaking before cutting our pieces. To save cardboard and time, we moved pieces around to better nest them on the sheets. On any pieces where the joining tab only had a single hole, we added a second hole to accommodate lacing together the pieces with wire.

We added snowflake cut outs to some of the biggest pieces to prevent the effigy from being blown around too much in the wind.

As the bicycle boxes were really thick corrugated cardboard, we doubled all the cut lines so the laser would do two passes.

Once the pieces were cut out, we sorted them numerically to make finding parts easier on assembly day.

Step 5: Assembling the Pieces

Every piece had to be tied together with thin wire. PenfoldPlant used zip ties which would probably have been faster and less painful on our fingers, but we were not allowed to use plastic so we couldn't go that route.

We assembled all 292 pieces over 12 hours with the help of 15 awesome YuKonstruct volunteers.

The cardboard was assembled in sections and then secured to the skeleton frame with more wire, screws and metal strapping.