Learning how to create armatures for stop motion puppets was a totally different journey compared to the creating characters in CG. It all started when I wanted to recreate the clay animation look in CG software so I had to make a clay character fist. But I never got to the CG world again - at least until this day- because I was captured by the charm of the stop motion animation. Making wire armatures which is simplest form of armatures for a puppet had me to try better and more complicated ways to make an almost perfect armature, I couldn't help myself to not to make it better and better! A year and half after my first crooked wire armature, I almost owned a nearly perfect ball-and-socket armature. Here I want to walk you through the general steps of converting raw , soulless metal into a moving , shiny armature ready to be part of a bigger art.
Iron sheets for plates
When it comes to making ball & socket armatures, making plates for joints is the most part of the job. From various available materials like aluminum, Copper, brass , iron and steel, there is a reason to choose each one. But if you want to have durability , smoothness in movement and delicacy , there is not much options. I found steel plates to have the most desirable outcome, because its hardness let the plate to be at minimum size and much more durable. But it's not that easy to go with Steel, because again for its harndess, the whole process needs sophisticated machinery tools and I didn't have such and in other hand I had not access to steel sheets here in my city anyway. so I had to find a way around this problem. What I had access to , was iron sheets, so I faced a big challenge: turning iron into steel. After a lot of research I managed to come up with a method to do So. The solution is to "Cook" the iron sheets with carbon-rich material in a high temperature for a long time like medieval blacksmiths ! So for the first step, I cut iron sheet into stripes that can go into the Furnace.
To the furnace
When cut into stripes , it is time to put them by charcoal and place it into the furnace for a hour or two. The result will be Carbon-rich iron but not yet steel. To turning carbon-rich iron into the steel it needs a process called "heat treatment". for now it is just like iron and could be worked on as easy as iron.
Drilling and grinding Plates
Plates are tricky. one of Challenges on the way of making plates is to make them identical, so each two of them could pair together. Because when tightened, there is a lot of pressure on the balls and even slight misalign in holes would result a bad movement and that is not what we want. I have made several templates for each joint size to have an identical output for each plate. For example, I have repeated holes from a 3mm joint template on the stripes.
Drilling and soldering balls
If we divide the whole process of armature making, we could name 3 major parts : Making plates, Making Rods and Hard chrome electroplating. Now that the plates are almost done, it is time to make the balls connected to the rods. there are several methods to make ball-ended rods , but I prefer to use the most strong one , which is drilling a hole into the balls, putting rods into the balls and silver solder it into the place. this method is the most secure way to make sure you will not end up with a broken rod at the end of the day. Since there are high temperature and soldering wax involved in soldering process, the rods will become dark and dirty after soldering, which will be cleaned later.
Time to electroplate!
Considering steel as the main ingredient of an armature, there will be a huge problem; Corrosion and rusting. There is moisture everywhere and moisture and steel don't get along. By time passes, the moisture in the air will cause the armature to corrode and become useless. So far I have had overcome all problems, but this one wasn't an easy one. The answer to problem was simple; creating a barrier between the surface of the metal and the outside moisture by a process called "Electroplating" or "plating" for short. In this process, electricity is used to mess with the electrons in the target metal to absorb atoms of another metal by their electrons to create a thin surface of that corrosion resistant metal. There are several methods in electroplating, like having copper as the plating metal, or zinc. But none of them were the answer of my problem. I need a very special type of plating called "Chrome" plating.Because of the very hard properties of Chrome, it is an ideal metal to choose as plating process for mechanical parts. But if you go with "No pain, No gain", you will assume that Hard Chrome plating is not that easy to do. A nice hard chrome plating needs a lot of cleaning processes, like polishing, then degreasing, and rust cleaning.The plating itself also needs the right amount of electricity current , at the right temperature which is not easy to achive because electricity heats up the metal parts and it effects the temperature of the acid bath and just two or three degrees out of the chart will result a bad plating. So many parameters involved, so many variables to watch and control, and the acid bath itself it a dangerous and messy solution. So at the end, with so many other problems, I achieved a good plating metal and I couldn't be more happy about finally achieving the last puzzle of the Armature making process.
A short demonstration of the electroplating system:
After almost a week working on an armature and all those drilling, grinding, polishing and plating, it is time to assemble the armature and see some result.