One of the most important things you need to consider is, quite simply, how will your puppet stand up?! The battle against gravity is a huge factor in stop mo (a fact that becomes very apparent when you try to walk a puppet). You have to ensure that your creation will stay on its feet, while it performs.
The easier way to achieve this is tried and true. You embed a "rare earth" magnet in the foot of the puppet. Then you build a set that has a thin surface, which you can access from underneath. From underneath, you apply a second rare earth magnet, and shaboom- your puppet is standing up.
These rare earth magnets are not your typical fridge magnet. Go get them at specialty stores. In Canada, look to Lee Valley Tools.
Often, the magnet from underneath is dropped into a metal cup, which intensifies its powers, and is also secured on to a short piece of dowel. This is what's known as a "magnet wand" (in the biz), and it just makes it easier to manipulate the magnet from under the set.
To embed the magnet in puppet's foot, you first go from your trusty scale drawing. You create a loop of armature wire that is ever-so-slightly bigger than the magnet (they magnets come in different sizes, find the right one for the size of your puppet). Then you braid your wire upward, as you would with an arm. Make sure you've used lots of armature wire, so you can trim the excess to the length you need for the leg.
Then angle the foot's loop at 90 degrees. You now have the foot armature, and the leg armature. "But I want a toe, too!" you say? Go for it. But this method gets you a nice foot/leg combo, and you have a heel joint, and you can do great animation. If having a floppy toe is essential, then do it. But in general, if your audience is focused on the toe flapping in what should be an overall engaging animated story, you've got problems. The last thing Joe or Jane average will be paying attention to is whether you have an animated toe. But, if you NEED that toe, you can fabricate a foot that has a magnet in the rear and a toe that can be animated. Design it, test it, and build it, you'll be fine. But I recommend doing it this way, first.
You will use epoxy (see earlier postings) to embed the magnet into this loop. Be sure to keep the ankle part of the wire free and clear of epoxy, so it can move. Another tip- be sure to keep the base of the magnet that will rest on the set level and smooth, and free from epoxy "gunk". You want a perfect surface between set and bottom of foot, so the magnets can do their thing. If there's gunk on the sole of the foot, you'll get wibble-wobble in your puppet. Not good.
After you've embedded the magnet, you can continue to build up the foot into the shape of the shoe you want. Of course, this technique (of embedding a big magnet) leads to, you guessed it, BIG shoes. If that offends your design senses, there's other options.
But back to the leg/foot at hand. With the foot done, just use your scale drawing to figure out where the leg bones will go, and where the square brass stock will go.
As with the other parts that have brass at their ends, that can slide in and out of armature blocks (hips, torsos), the fit will be a bit loose. That means as you walk that puppet, a leg will want to actually fall out! Eeek. So use a thin layer of contact cement to bond the leg into the hip block. Not too much, or you'll never get it out if it breaks.
For legs that will have pants or long skirts, you just need to bulk it up with some foam. If you will actually see skin, you need to use the latex build up process, as discussed earlier. Again, costume means a great deal to puppet making. A long skirt means easy legs to make. A short skirt means a lot of skin that needs to be made (tricky). Below is an image of the Mom puppet's legs. She has a fairly long skirt, tha shows a bit of skin at the bottom. As you can see, there's latex skin built up to where the skirt will, but not much further.
So let's say you want dainty, "Tintin" style feet. Feet that are far too tiny to embed a big honking magnet. You can use tie-downs.
This entails embedding a tiny nut instead of a magnet in the foot. Then you put holes in your set where you need them, and feed a bolt of the right size up and into the nut. There you go, a sturdy puppet with tiny feet. The trick is that it's now tough to move that puppet around, as you must drill holes in the set for each step that puppet takes.
Good with the bad- magnet feet are pretty easy to make, and easy to move around on the set, but your design might suffer.
Tie-down feet look elegant and beautiful. But they are trickier to make (those tiny nuts are tricky to embed) and are trickier to move around on the set.
You get to choose, lucky puppet-maker.
As with all these approaches, you will have worked hard to create a part that just might break. So since legs/feet take time to make, I recommend a story that doesn't involve millions of shots of puppets walking. The less stress you put on the legs/feet, the less chance they will break.
If your story insists on lots of walking, so be it, but go into your production planning knowing you need to take time to make extra legs, cause odds are they will break.
Also, extreme animation in terms of lots of jumping, deep bending will stress your leg/feet wires a lot. So again, either create a story that doesn't require this (and you won't break your legs) or if it's essential to the story, make yourself extra legs.
It's much easier to make extra parts in advance of shooting so that during animation, if you break a part, you can just swap in a new one. If you have to stop everything, pull out all the puppet making materials, start working with epoxy, latex... it really slow things down. Have extra pieces made during the puppet making stage of things... you'll thank yourself during animation.
How many extra parts to make- spines, arms, legs, feet, necks?... it completely depends on your story, and on YOU as an animator. Some animators are tough on puppets, they stress the puppet a lot to get a performance, and thus break a lot of parts.
Other animators have a lighter touch, and puppet parts last longer for them.
I didn't break a single puppet part on TFS, but I had extras of parts standing by. The animation was fairly limited to some walking, running, (each puppet only have to do a bit of each), then facial animation, basic weight shifts... some throwing, general hand acting... so nothing MASSIVE in terms of stresses.
Plus, I made the parts well. And I am an experienced animator that can get a performance out of the puppet without snapping things. I also animated in what you'd generally call a "Good Enough For TV" style. It's pretty limited, abbreviated, conservative. It let me get lots of shots done quickly, got the point of the story across, but didn't take super long, since I didn't have much time scheduled to animate. All these factors worked together so that I didn't break any parts.
Only experience will really tell you how many extra parts you need. So get making puppets and puppet films... it's the only way to learn.
