A 3D Animator’s Guide to Stop Motion.

 

Part 01 – Building your armature

 

Introduction

 

Here is a tutorial on how to build a cheap-o wire armature for your own foam or Sculpey stop motion puppets.  This method is good for experimental or short-term projects (and I’ll explain more on that later.)  I find that most tutorials on how to do this lack the basic concepts explaining how to build an armature and others are built just plain wrong.  In my opinion, its way more important to understand the concepts of what you’re doing than to get a list of steps. So before we get into any specifics with wire and plumber’s epoxy, let’s talk briefly about what makes for a good armature.

 

Just to preface a bit, I’m not an expert in this by a long shot and I’m a bit of a windbag to boot. There are many people who do this way better than I ever hope to. In fact, what I’m passing on to you is knowledge that I gained from Dino Crisanti (http://www.traegons.com/default.html) I’m sure there will be plenty in here to disagree with, so feel free to correct, critique and contribute as much as you like.  Also if you injure or kill yourself while trying any of this, it’s not my fault. Use your head and think about what you’re doing.


 

 

The Basic Principle of Resistance

 

So what makes a good stop-motion puppet armature?  Control.  Like a 3D model, you want to rig the character so it allows you to move only the parts you want it to. Imagine every time if you moved your Maya model’s hand, his leg moved or his hip moved as well. It would make it very difficult to animate.  The same thing goes for a stop motion puppet.  Building your armature properly will make it so much easier to pose and animate your puppet. 

 

Unlike 3D models that have their root at the waist, generally stop motion models are “fixed” from the feet. (There are a few times when this needs to be ‘broken’ such as when the character jumps in the air.)

 

 

In order to make your puppet easy to animate, you will need to make it continually more pliant (less resistant) the farther you go from the feet and spine. To restate this ‘cause it’s important, the parts with the most resistance in your puppet should be the legs, then less resistance in the spine, less still in the neck and arms, then followed by things like fingers and possibly the facial armature.  If your knee and your elbow are equally pliable, then when you try to bend the elbow, the knee will bend also (at least, more than you’d wish.)  When you move the wrist, you want as little as movement as possible from the elbow.  When you wish to bend the elbow, you should be able to do this with as little movement as possible from the shoulder.  And in both of these cases, you shouldn’t have any movement in the legs. I’m going to call this first concept the ‘basic principle of resistance.’

 

 

The second important concept is that in order to animate a puppet and get any type of consistent smooth motion out of it, it must be screwed into some solid surface. If the puppet is standing on its feet, you should drill holes up through the table and screw bolts from underneath into the bottom of the feet (called tying down the puppet.)  When animators ‘walk’ a puppet across a stage, ever step requires a new hole drilled in the table and the old one filled in with wood putty and painted over. If you are just getting started in this, I recommend using a pegboard type surface that has predrilled evenly spaced holes in it. If your puppet is going to be sitting the entire time, you will need to create a tie down in his butt and something solid to screw it into (not a movable chair, for example.)  If the puppet is holding objects and putting them down and picking up others, you will need tie downs in its hands.

 

 

The feet when tied down, they are not movable (pliable) at all. With a single foot screwed into the surface, your puppet should be able to stand on one leg. Like in 3D, build the model according to what you are going to have it do. I’ve built a few puppets without legs because they were always seen only from the waist up.


 

Therein lies the rub

 

 

Professional armatures use these little what-cha-ma-jiggers to control their pliability.  It is essentially two ball joints made by two balls held together by two plates and a screw. Rods are attached to the balls to make the bones. The tighter the center screw, the more resistance the joint has. Before the puppet is covered with foam or clay, these joints are ‘tuned’ for resistance. I’ve heard that during the shooting of stuff like Nightmare Before Christmas, animators will cut the foam and reach a small screwdriver into the puppet to adjust these joints from time to time.  Then the puppet builders will patch up the slit and then paint over the scar.  This type of rig is generally pretty expensive to build, very nice to animate with but not very necessary if you’re just getting started.  If you are interested though, here is a link to probably the cheapest way to get these joints at $5 a pop. http://www.sci.fi/~animato/joints/joints.html

 

 

 

The armature that I will tell you how to build is made of wire. The resistance of the joints comes from the wire itself.  The bones will be made by encasing the wire in PVC tubes or plumber’s epoxy.  There is no practical way to ‘tune’ this puppet once you’ve made it. Also, the very nature of wire is to become more pliable the more it’s bent. So your puppet will have a limited life span before the joints become lose and then break. But it’s so cheap and easy that you can make another one in a couple of hours. The technique that I use will allow you to possibly do a patch job as well.

 

But therein lies the rub.


 

The Basics of Building

 

 

So begin visualizing your dreams with an actual-sized sketch of your character, arms stretched out to the side, much in the same way you would plan to model a character in 3D.  This will become your blue print for your armature and you will layout the wires directly on the drawing (hence the actual-sized part.) Get yourself some different gauge aluminum wire (around 14 gauge and smaller.) As the gauge number goes up, the thickness of the wire goes down. Two or three different thickness should suffice. It doesn’t matter too much as long as you keep the ‘basic principle of resistance’ in mind while you’re building. (I’m using the number 14 for ease of reference; don’t consider it to be the rule.) With just a little experience, you should be able to figure out what is the right gauge based on how much clay or foam you plan on supporting.

 

If you have any large masses in your puppet like the head or the upper torso, plan on using Styrofoam to create the basic mass and then cover it with Sculpey.  You don’t want a large head made entirely from Sculpey.  The head will weigh a ton and the wire used to support it has to be bigger.  That makes your torso wire thicker and your legs thicker even still. The harder it is to bend the wire, the more rough you will have to be with your puppet to move it, displacing more clay as you struggle it into position. You will know if the wire for the legs is too pliable if your puppet isn’t able to support its own weight while standing on one leg. Finding that balance will vary from puppet design to puppet design.

 

To get different resistance throughout your puppet, you not only use different thickness of wire, you use double the thickness in some cases.  Start by making the each leg of your character with the 14-gauge wire.  Double wrap it so it looks something like the drawing below with a loop at the bottom of the leg. The length of this should also include the length of your puppet’s feet. The leg is going to be the most resistant part of your armature. So what’s the problem here?  Going back to the principle of resistance, you see that the knees, hips and ankles all have the same pliability. It’s not ideal, but in the interest of simplicity, it’s appropriate for your first few armatures.  Try bending it.  Hopefully, it shouldn’t require too much muscle to get it to move and is stiff enough to support a fair amount of clay or foam.

 

 

In order to tie down the feet of your puppet, you need to imbed some kind of nut in the feet.  I like using wing nuts because there is more surface material for the plumbers epoxy to grab onto. Wrap the wire loops around the wing nut. Sometimes your feet will be too small to accommodate the “wings” on the wing nuts and you’ll have to use regular nuts.  In this case, use an industrial strength epoxy made for adhering metal to join the wire and the nut. Then wrap in plumbers epoxy for good measure. Here is an example of a tie down using regular nuts. http://dolphin.upenn.edu/~jmosley/tutorials/claymationArmature/armature.html

 

It’s a good idea at this point to have a scrap piece of wood to drill a hole through and tie the wing nut down before you epoxy it.  This way, you’ll make sure not to get epoxy in the threads and you will have a flat-bottomed foot as well.  It’s possible to create a heel tie down and a toe tie down with wire between to get more control to animate foot roll and such. You will need two nuts and some thick wire between, you over achiever you.

 

Plumber’s epoxy is an A plus B type of putty that gets hard as metal when it cures.  You can drill it and sand it.  It’s tough stuff that probably gives you all sorts of cancer. I recommend wearing gloves.  Once you mix the putty, wrap it around the wing nut and wire to make your foot. You can, and probably should, envelop the entire wing nut in the epoxy (not the underside though.) Repeat for the other leg.

 

Without bones, you puppet will be able to bend like the noodle cartoons of the 30’s. To get a more realistic moving puppet, you will need to control where the wire bends. If you’re going to use pvc tubing for bones, you have to create the upper and lower leg bone at this stage. Bevel the edges so the corners won’t catch on each other.  Use a file to take them down to 45-degree angle or so. Also, leave enough space between them to allow your knee to bend 90 degrees or more. If they are tight up against each other, you won’t be able to bend them at all. You can also create the bones with plumber’s epoxy. I’ve never used this method, but it makes sense to me that it’d work. The only possible advantage I can see to pvc is that your bone will be guaranteed to be straight, while with the epoxy I imagine its more eyeball guesswork.

 

 

Create a spine using a single wire (non-wrapped). You will connect the legs to the spine either using a bracket or plumbers epoxy.  There are many ways to connect these actually. It doesn’t matter much as long as it holds.  I like the bracket.  Even though it’s a bit heavier in weight than other methods, it allows me to replace a single length of wire (or appendage) without having to ditch the whole armature.  What ever you use to join the wires together, make sure that you can really tighten the heck out of it or really create a tight bond.  You don’t want your wires moving/spinning around or slipping out.  Good news is that aluminum wires are pretty malleable. If you use a wrench to tighten this kind of bracket, the wires will mush together and stay put.

 

 

The arms are not too different than the legs.  Create the lengths by using a wire that is smaller (more pliant) than the spine.  You can use a smaller gauge and double wrap it, just make sure that it’s still more pliant than the single length of wire used in the spine.  Place your upper and lower arm bones. You may want to have a tie down in the hands as well.  It allows you to screw objects into your puppets hands or do something wacky like a handstand (although the resistance principle tells you this is hard to animate this way and you should use an additional support arm.)  Here is an example of a puppet with a ton of tie downs and a support arm. http://forums.awn.com/showthread.php?t=1834 Note all the tie downs in the torso and pelvis.

 

If you want finger control, use an even smaller gauge of wire for finger loops.  I’ve found that I’ve never needed bones in the fingers, but it may depend on what scale your puppet is.  The wire used in fingers can be very thin. The fingers should never do any of the actual ‘holding’ of objects (that’s what the hand tie down is for.) Use plumber’s epoxy to join the fingers to the lower arm.

 

            

 

Create the neck using the same thickness wire as the arms.  If your character is big headed, attach the wire to Styrofoam. Make a loop and cut/drill a hole down into your Styrofoam ball.  Put the wire inside the hole and use some kind of glue to keep it all together.  (I think I remember hot glue works pretty well, or was it that hot glue eats away at the Styrofoam? I can’t recall.)  If your puppet has ears, it should be similar to fingers.  Clamp (or whatever) the arms and neck and upper spine together similarly to how you connected the pelvis.

 

Now your puppet should be just about ready to be covered with Sculpey or foam. There are many different methods of handling the head. I have not found a good way to make an armature for the face. My best success was using a thin wire for the brow and another for the lower jaw of a foam puppet. This puppet was able to express anger and surprise, but not much else.  There is no need for eye wires.  Actually, it’s easiest to use glossy beads with the holes as the pupils. The holes in the beads will swallow the light and appear black.  Paint an iris around them. Stick a toothpick in the hole to aim them.  Some puppets have replaceable mouths, others have to have the mouth sculpted into position and then solid (baked) teeth placed in when appropriate.  Others have replaceable heads.  Different techniques make sense at different times and I will get into this in more depth in Part 02.

 

Conclusion

 

Obviously, there are many different ways to rig your puppet.  As long as you keep in mind the basic principles, you will know what to shoot for.  Stay tuned for the next two installments.  Part 02 will be about how to cover your armature focusing on heads and faces. Part 03 will cover basic tools and techniques for animating stop motion puppets.  Good luck and happy animating!

 

P.S.   Here is a good page of resources. http://www.stopmotionanimation.com/resources/armatures.htm

 

 

Todd Elliott

toddmelliott@yahoo.com

www.toddelliott.com