The prototype was to simulate metal as the intended material for manufacture.
I wanted to enter, but with a humorous play on words at the centre of my design. The Porkupine would sit on a table, as roast pigs did in the past (sans the apple). The quills of the Porkupine would be made out of rolled up napkins/serviettes, similar to the quills you may have seen in the Porkupines cousin, the porcupine.
This instructable is an interesting set of steps showing how I got to the final form, as well as how I simulated the finish of cast alluminium, using corrugated cardboard, and automotive body filler.
It illustrates that corrugated cardboard can be used as an effective model-making and prototyping material.
Step 1: Maquette Made From Clay
I made several maquettes before setting my mind on this one.
You can see the size of this to be approximately 50mm long (2 inches). I photographed the model from the front and top, and scaled up the images on the computer. I then printed these out, and began laminating many layers of corrugated cardboard.
I used double-fluted cardboard which was approximately 8mm thick. I glued layer upon layer to create a solid 'block' of cardboard about 15cm thick (6 inches).
Step 2: Shaping the Cardboard
Fine shaping was done by hand with a bastard rasp, and sanding block.
I created tapered cardboard tubes using natural gum-tape (as one would use in packaging boxes) I purchased this at the local craft store.
I drilled holes through the shaped Porkupine body using a cordless drill with a 13mm bit. The holes wern't as accurate as I had hoped, but I guess that is a downfall of drilling at an angle through a block of corrugated cardboard. The holes seem to drift in varying directions, I accepted this and processed along without much frustration.
There is a piece of masking tape around the nose of the piggie. This was because the cardboard began de-laminating through being handled. I reglued with a bit of cold-glue and taped it together.
Step 3: Bodyfiller Screed
Once dry, I proceeded to screed the entire form with body-filler. This was an automotive flexible polyester body-filler, from the automotive industry. You mix in a catalyst and then apply...
I had to apply several coats of body-filler, sanding and forming the Porkupine between each of them.
I bonded a piece of 2mm white ABS plastic to the belly, allowing for a smooth underside surface. This also covered up all the opposite ends of the internal cardboard tubes.
Step 4: Nose, Eyes, and Ears
Eyes: I used the brown modeling putty (shown earlier) to cast the eyes out of white epoxy. This was done by depressing my finger into the putty, leaving 2 small dents, which I filled with epoxy.
Ears: The ears were made from the same body filler as used on the body. It was mixed and smeared into a rough mold made from a few bent pieces of plastic. I used some hilti pins as added strength when bonding the ears to the body. I used body filler as the bonding method to hold, and smooth up the join between the ear and the body.
I smoothed the edges with more body filler, and began using finer and finer sand paper... ending up with about a 800 grit paper. This fine grit was fine for the next step... painting.
Step 5: Painting
I applied about 3 coats of primer, with sanding with 800 grit between coats.
Finally I applied the metallic spraypaint in 3 coats...
Step 6: Porkupine
Please let me know if you like this design, or may be interested in buying one of these. I am able to create an accurate silicone mold and cast alluminium replicas (alluminium+resin mix) of the Porkupine. It is able to hold 18 paper serviettes, and is tame enough to keep in a drawer. It is Halal, Kosher and also a friend of the Vegan.