Puppetry and Animatronics

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General principles of operation
There are five principle methods of operation: marionette, hand and rod, cable, servo or hydraulic/pneumatic. These can be intermixed as required. Each has good and bad points, but by thoughtfully using different technologies, a combination can be achieved that provides the required results.

More sophisticated puppets may require up to four operators; more than this will become unworkable and a computer control system will normally have to be used.

Marionette
A traditional method first seen by many people on programs such as Thunderbirds, Andy Pandy, Captain Scarlett, Team America, Being John Malkovich and the like. It usually gives the animation a very particular look and feel with certain restrictions and benefits included. It is usual to control a marionette from an overhead gantry and the construction restrictions involved with this should be seriously considered.

The Marionette method of operation is often the first introduction that people will themselves have had to make a doll or similar come to life and though a very particular skill-set is required this should be considered as a solution to many contemporary animation sequences. This method is often not considered because of a couple of potential issues: the strings can be seen and making something walk convincingly using this method is extremely difficult, though not impossible. The use of lines between the object and the operator does not rule out a combination of methods such as rods or r/c servos but it would not be usual to use this with cables, (see Cable control).

Very fluid moves can be achieved by the combination of a rod and line; consider the gymnastic discipline using the ribbon to conjure up images of the type of thing that we mean.

The use of very thin lines that are camouflaged to match the background can reduces the visibility of the lines though it may be of more benefit to make the lines very visible to help post-production spot them and take them out of the picture. The ease with which post-production is now able to restore backgrounds and remove rigs has worked in favour of both this and rod operation methods.

As a word of caution: always insist upon seeing some evidence that the puppeteer can make a convincing job of the animation required. They should almost ‘live’ within the puppet to bring life and character into what is often little more than a lose jointed doll. Ensure that they understand the differences of the type of body and joint construction available and how that will reflect upon the movement. Scale and weight will also need to be considered. As these increase the moves may become more realistic, but there will be a point at which the size will start to work against the puppeteer because of the weight involved. Puppeteers are like actors, some can and some can’t!

Hand operated
This is the traditional style of operation, where the puppeteer has a hand inside the puppet, but can be used in conjunction with more sophisticated animatronic effects to produce very effective movements. As an example, the body movements of a puppet can be by hand, with facial expressions given by other means.

More sophisticated puppets may require a large number of operators; this may introduce rehearsal and co-ordination issues that may stand contrary to the available budget and a simple break down of the operation should always be considered carefully.

Hand operation will provide very sensitive, quick and adaptable control, it is often used in conjunction with rods for the arms and is generally a lower cost compared with more sophisticated means of operation. It is preferable for the operator to see the puppet or to have a reversed monitor to refer to.

Cable control
This consists of making mechanical devices that are operated by pulling cables to create movements at a distance from the operator. The cables used are like bicycle brake cables. They must be pulled to make a mechanism move, if you push them they bend, so to move it back you must pull a second cable to move it the other way. This principle is called reciprocation and means that each movement must have two cables to make it move back and forth; it is a pull-pull system. Under certain circumstances either a spring or a push-pull cable (stiff wire) may be used to reduce the number of cables from two to one.

Reciprocity ensures that every movement (axis of movement) must have two cables to operate it. For example an elbow has only one axis of movement (up and down – two cables), while a wrist has two axes of movement (up and down, side to side or anywhere in between – four cables). This can become a problem on smaller, complicated puppets, where the bulk and number of cables becomes difficult to manage.

Although made of steel, cables do stretch, so over longer runs sensitivity of control and functionality may be lost. For this reason it is important to keep cable runs as short as possible, so an operator may need to be placed near to the puppet; generally no more than 2 metres.

Cable operation allows small complex puppets to be created with a reasonable level of adaptability and with strength to their movements. Although the operator is some distance away, feedback is provided by how hard the cables are to move, this allows a good level of sensitivity, though not as good as for a hand operated puppet. Again it is preferable for the operator to see the puppet or to have a reversed monitor to refer to.

Servo control
A servo is an electric motor and gearbox unit that is very controllable and is used to turn a number of degrees in either direction. Servos are used as push-pull units, so each axis of movement needs only one servo motor. These are quite small units and are usually built into the puppet. These servos can be operated either by remote control or be ‘hard wired’, where a wire leads directly to an external control box.

Servo control can allow a puppet to operate with little or no physical connection to anything else, allowing an operator to be distant. The wires that lead to servos are far smaller than bicycle cables and the remote control equipment need not be much bigger than a matchbox.

Servo control allows self-contained puppets to be made. It is also a relatively easy technology to use, so often becomes the method of choice over cables if the amount of strength required is not
too high. Servo control is operated by moving a slider or lever, so there is no feedback, and consequently the operator has little sensitivity to how the puppet is moving. The operator must be able to see the puppet.

Very sophisticated puppets may require a computer controlled performance system to be used. This allows pre-programmed moves or sequences to be played back to the servos in the puppet. This can also be done as a combination of live action moves by the puppeteer and playback via the computer.

Hydraulic or pneumatic control
Pressure cylinders (pistons) operate in a reciprocal manner and usually have two lines (pipes) enabling them to extend and contract, producing very powerful forces. This and their relatively large size, generally limits use to large puppets.

Using cylinders will provide a very powerful motive force, but will have two lines for each degree of freedom and provides no sensitivity. If using hydraulics the operator can be quite distant, but with pneumatics, the operator needs to be local or the control becomes ‘woolly’. The operator must be able to see the puppet.

Skins
In all cases the skin must be sculpted to allow the puppet to move freely. This may mean that certain features, like skin folds, are required – for functionality rather than appearance. It may also mean that the usual foam latex skin is replaced with the more expensive silicone skin. This is harder to work with and to make, but offers a level of flexibility and flesh like appearance that latex cannot match.

First considerations
A puppet provides a live performance, this means that an action may not be repeatable, but it also means that flexibility, live interaction and spontaneity are possible.

Try to get an animatronic specialist involved early on in the project and take advice on how the puppet is likely to function. Be open about your budgets, animatronics can be very cost effective or spectacularly expensive, your supplier may be able to guide you around the nasty areas.

Think carefully about what the puppet needs to do, eliminate everything that is not essential and always ask if there are simpler ways to achieve your goals; one of these is to build a basic animatronic onto which further aspects of movement are overlaid using computer generation techniques. Once you have a cost for the basic puppet, use any surplus budget to buy the frills.

Understand how the puppet functions in terms of the operator’s requirements – positions, viewpoints etc – and work with the set designers, technicians and director to make the shot work for everyone.

Budget expectations
Animatronics are never cheap, question what you are getting if they are, but a well thought out simple puppet can be reliable and need not be expensive either.

As more features are required on a puppet, it progressively increases in complexity, increasing the cost exponentially; so a head with twice as many movements may cost four times as much.

It may be far more cost effective to commission a simple puppet and overlay CG features, but remember the spontaneity and performance aspects will be lost.

When budgeting allow considerable downtime in the shooting schedule – the more complex the puppet, the more time will be required for set up, rehearsals, breakdowns and maintenance.

Questions to ask
Can I see your show reel?
What have you worked on?
How is it best to allocate my budget?
Is it best to undertake this job as an animatronic, CG or as a combination?

Problems to watch out for and things to do
- Reliable animatronics take time to build.
- Ensure that if you are using remote control systems, there are no other users in the area, because their equipment may operate your puppet.
- Over complication is always a temptation with animatronics and the more complex it is, the less likely it is to work or work well. Keep it simple, which also has the side effect of costing less.
- Animatronics are generally very delicate; they are manufactured to do a specific thing and if they are made to do something else they can break. This most definitely includes bystanders moving a puppet’s limbs, head or features. Do not let anyone touch or operate a puppet without the puppeteer being present, and even then it should be discouraged.
- Animatronics are generally very delicate; be prepared for when they break or misbehave. The technician accompanying the puppet can mend all breakdowns on the set, but as the puppet must be opened, the fault diagnosed and repaired and then closed, the down time can be considerable. Try not to pressure the technician, he/she is well aware of the costs of downtime and pushing now will only make a repeat breakdown more likely. It is difficult, fiddly work – respect that.
- Animatronics really don’t like water unless they are built for it, and even then they aren’t really sure.

Know the jargon
Air muscle An inflatable bladder used to force mechanical components apart
Armature The ‘skeleton’ of a puppet
Axis of movement Each movement pair is an axis of movement – e.g. up and down, in and out, side to side
Cable (pull-pull) A bundle of fine steel wires only used to pull mechanisms
Computer controlled The operator moves the puppet, the computer records the moves, they are edited and performance system played back as required
Cylinder A device for pushing or pulling mechanisms when using hydraulics or pneumatics
Feathering Covering the skin of a creature in feathers
Feedback The response felt by an operator indicating the operational status of the puppet.
i.e. the feel of the controls tells the operator what the puppet is doing
Flocking A simple way of applying short hairs to look reasonably like fur
Gantry A walkway or platform above the area that puppeteers will operate a line hung puppet.
Gimbal A type of joint that incorporates multiple axes of movement, e.g. wrist or shoulder
GRP/glass fibre/ carbon fibre Common materials used for making the shells that form part of the ‘skeleton
Hardwire/d Connecting servos to the control system by wires rather than by radio control
Hair/fur punching Inserting hairs into an artificial skin; one or a few at a time
Hinge A type of joint that incorporates one axis of movement, e.g. elbow
Hydraulic Using oil under pressure to activate devices for exerting force, usually cylinders (pistons)
Latex Rubber that is injected into moulds as a foam and forms a skin for the puppet.
Foamed latex is the usual material used
Lines The pipes that take air and hydraulic oil to and from cylinders
Marionette A particular type of puppet that is controlled via strings and controlled from above by a puppeteer on a gantry, (see Gantry)
Mech/mechanism The mechanical parts of the animatronic
Mechy A technician specialising in animatronics
Microwave A high specification and expensive wireless control system for highly complex or
expensive models
Pivot The point about which a limb or other feature rotates
Pneumatic Using air under pressure to activate devices for exerting force, usually cylinders (pistons)
Push-pull cable A stiff wire, that can be used to push and pull mechanisms
Radio/remote control Using radio waves to send the operating signals to the puppet
Reciprocating Using two opposite forces on one system. E.g. pulling a lever one way then the other
with two different cables
Rod/rodded Using thin rods attached to parts of the puppet to enable it to be moved. The rods are
generally removed from shot using post production techniques
Servo An electric motor used to accurately move parts of the animatronic mechanism
Shell Part of the ‘skeleton’ of the puppet, moulded to form a hollow cavity into which
components get fixed
Silicone A type of rubber used for moulding realistic skins; it is expensive and can be difficult
to use so will only be used if really required
Skin The outer covering of the puppet
Snake A common type of mechanism using a number of gimbal joints in a row, many gimbal
joints will form a snake, a couple make a wrist and five or six would make a neck
Stop motion A type of puppetry that requires the action to take place in frame by frame steps.
Not used for interaction with other things. Think “Wallace and Grommit”
Thunderbirds Probably the most iconic show using marionettes