I'm currently working on a project to build new fab lab in Seoul. Last week, there was a groundbreaking ceremony for the construction, and the main part of the ceremony was a traditional ritual called 'gosa'(고사).
고사(告祀) [gosa] is a traditional ritual that is widely practiced in Korea, and also other East Asian countries like China, Vietnam, and the island of Okinawa.
The ceremony is basically to wish safety and prosperity to sprits at the beginning of something important; For example, construction, long journey, movie cranking, opening of a business, and even when someone buys a car. Here's more detailed explanation of the ceremony from Kotaku : http://kotaku.com/why-snowpiercer-started-with-a-digital-pig-head-1595183808
Traditionally, the head is processed into gelatin-rich pyeonyuk(편육, pressed meat) after the ceremony and shared together. However, because not many people these days have time to cook pig heads, people prefer to use fake plastic pig head for convenience.
So if people already use creepy plastic pig heads instead of a real one, why don't we just print it?
That's how it started.
Step 1: Print Me a Pig Head
Fortunately enough, there is already a 3D scanned data of a real pig head from a Thingiverse user Shapespeare. (Thanks a lot!)
It's a fairly detailed model with all those bumps and wrinkle of skin and I wanted to print it in real size, which is about 360mm x 714mm x 300mm.
I have access to some large size FDM printers, but given the time I have and other work I have to do, I could not risk the printing failure that is quite frequent in printing large models with FDM printers.
Also, printing the whole head with single color plastic wouldn't look good enough if not creepy.
Then one image I saw last summer in Barcelona crossed my mind.
Anastasia Pistofidou is a talented designer and architect with wonderful personality who works for Fab Lab Barcelona. She created a life-sized 3D printed statue of a man for FAB10 conference last year.
Instead of printing the statue at once(which I'm sure not even was a option), she patchworked multiple parts 3D printed in different colors. This technique also eliminate the need to fill the gaps between parts as the patchwork itself is stylistic enough without additional processing.
I also found this excellent article on printing horse head with similar tactics.
Step 2: Crack the Head!
I used netfabb basic to cut the head into smaller parts
The printer I used (http://opencreators.com/ocp/) has 150 x 150 x140mm build volume, so every part was cut to fit into the box.
Then I deleted inner blocks to reduce printing time.
At last, the head is separated into 17 blocks.
Step 3: Put Your Money Where Your Mouth Is
The highlight of the ceremony is when people put money into pig's mouths, nostril, and earholes to wish prosperous business. Because there wasn't any hole in the original model, I used TinkerCAD (https://www.tinkercad.com/) to make holes in nose and ear parts. I usually use TinkerCAD to do simple boolean operations like this. It's very easy and convenient when you don't need precise measurement.
The all the parts assembled in one piece in Rhino 3D for color coordination. I used only 4 different colors to make the printing process less complicated.
Step 4: Printing Frenzy!
As a fab lab in planning, we only have a couple of QUBD printers. Since I didn't want to spend my whole weekend watching and wrestling with 3D printers (I already have plenty of experience..) I looked for a place where I can simultaneously operate multiple 3D printers.
Opencreators(http://opencreators.com/wiki-home) is a Korean 3D printer company that has a showroom which offers 3D printing service with a reasonable charge of 3,000 KRW (approximately $3) per printer-hour.
With 0.2mm layer height and 1.0mm shell thickness, the estimated build time in Cura was 60 hours in total. Thus yields total charge of 180,000 KRW. Luckily there weren't much people around, and we were able to run 10 printers at once using ABS filament.
We collected the printed parts the day after and started assembly. I used syringe type Araldite to glue different parts together. It's a super strong adhesive consisted of two types of resins. They must be mixed thoroughly before usage. It takes about 20~30 minutes to fully cured. I normally cover table with masking tapes for a mixing plate because in this way the plate(?) is firmly fixed, cheap, and easy to through away after use.
Step 5: Gosa
Finally on last Thursday we had a little ground breaking ceremony. The site is an old warehouse in Seoul and will go through complete renovation in following months to be reborn as a fab lab.