We continue our look at the basic workings of action figures today with swivels! A basic bore at the neck, shoulder, and hip but a welcome helper at the bicep, waist, and thigh, swivels are everywhere on a Transformer. How do they work and what can go wrong? Keep reading to find out!
You've probably noticed that your arms do more than just flex at the middle along a single axis. Arms can be swung at a 180-degree arc, more or less. Granted, to fully exploit that range you're bringing a ton of different muscles as far up as your shoulder into play, but in toyland there's a simpler solution.
A swivel is a two-part mechanism, a peg and a socket, allowing one part to turn. It's one of the simplest joints you can possibly make. In comparison, 90% of the toy world's hinges require at least three parts: the upper part, the lower part, and an axis for them to work around. Some hinges include plastic "bumps" that socket into one or the other half of the hinge, but as with most inexpensive solutions it often doesn't work as well as the more expensive equivalent.
Not only does ExVee's photo show a whole mess of swivels in action, it's great to show where they are in the arms and legs: Pyra Magna's thighs change color at the swivel, and so do Hot Spot's biceps.
A swivel in the shoulder or hip is the most basic articulation possible. Among the simplest styles of action figure, popularized by Kenner's vintage Star Wars
line and still haunting us today, had swivels at the neck, shoulder, and hip, and that was it. Not really very accurate or satisfying in replicating human motion - though eventually designers did figure out that with a more dynamic sculpt you could get less cadaveriffic results than Kenner used to get.
But when used mid-limb or mid-torso to supplement other joints, swivels make better-than-human range possible. Nothing on the human body is designed to turn a full circle, but you can turn a toy's waist or feet backwards and a dozen other things that sound incredibly painful if you think about doing them to yourself.
On Transformers, most wheels are technically swivels as well, being a loose-fitting, smooth-moving peg inside a socket to simulate an axled wheel. Such is the case with Beast Hunters Voyager Optimus Prime, just to pick a nearly random example.
Sounds too simple to mess up, right? Don't be silly: even the best of humans can mess up anything.
The biggest fear is that the peg breaks off. That can be a serious problem in those swivels where long, thin pegs are inserted into a limb, as with wrists and ankles. (And when the peg gets stuck up in there? ARGH
.) When the design is relying on tension to maintain a position, excess tension is the enemy as it can shear a peg off incredibly easily. Soft plastic pegs can also tear or rip off gradually if they meet too much resistance in the wrong places.
Many pegs for biceps and thigh joints are shallow pegs with a flared head or lip; these are usually referred to as "mushroom pegs." Turning smoothly can be a problem with mushroom peg swivels depending on how they're molded. With the close parts fit often required of the modern Transformer, it doesn't take much of a seam or very much flash (excess plastic that is ideally trimmed at the factory, but not always) to make a swivel difficult to manage, or even to push the peg out of its housing. Fortunately this is generally a non-fatal problem that can be fixed with some simple filing or sanding.
As with hinges, individual swivels are limited to a single axis of rotation, though at least they can turn in a full circle. But there is a more versatile option. Next up is the final part of the articulation triumvirate: the ball joint.