The Brave new Pink Flamingo (Part 2)

BNPF Assembly

Now that the parts are electroplated, it is time to put everything together.

BNF48 NeckMech PlatedAssembled.jpg

The Neck

The neck is the heart of the Brave New Pink Flamingo. It is a 2-stage tentacle mechanism with a 1/8th inch diameter speedometer cable as its core.

BNF50 Servo Installation.jpg

The Body

When I started seriously considering the use of 3d printing for animatronics, my first thought was “how awesome would it be to just print up a mechanism and all I needed to do was drop the servos in?”. Well, it never really worked out that way, but I made a good attempt at that goal with this system. The body was 3d printed as three different layers, and when screwed together, accomodated three servos with pulleys and cable housing terminations, and integrated perfectly with the neck mechanism.


Ther servos I chose for this project were three Hitech 805bb servos. They are fairly strong and really cheap (~ $40 each). There are servos out there that are two thirds the size and are three times as strong, but they cost four times as much. So there you go.

The Legs

Flamingos have long legs and the Brave New Pink Flamingo is no different. This part of the project actually ended up being a tremendous lesson for me in the structural limitations of 3d printed parts.

BNF51 LegStructure Fail.jpg

Aw Snap! I designed and printed the components meant to serve as the legs and hips of the BNPF. After assembling these parts I didn’t like what I saw. So I gave it the “I wonder how easily I can break it” test. Oops, too easily. Back to the drawing board.

BNF55 LegStructure Redesign.jpg

One of the great things about 3d printing is the ability it grants to try out different iterations of and idea without a lot of man hours involved. In the picture above you can see where the first leg structure failed and how I beefed it up in the second. If I had spent the time machining these parts and had this kind of failure, there would have been much wailing and gnashing of teeth. As it was, it was more a matter of “huh, look at that…”. It was a good learning experience.

Designing for the Material

When one learns to design mechanical systems made out of metal, like I did, there are certain things one takes for granted, like strength and durability. So, moving forward with this project, I had to make it a point to stop and think about what I was asking the materials to do. It’s not a difficult thing to do, but it was an interesting process, at the time.

BNF54 LegStructure Redesign.jpg

Here is an example of the shift that took place in my design approach. The project called for the whole body and neck assembly to elevate 120 degrees on a .25” diameter steel shaft suspended between the hips of the BNPF. The idea was to use a .5” bore metal shaft collar to clamp down on a printed plastic hub in order to hold that steel shaft. On the left, is the first hip hub part and the off-the-shelf shaft collar I intended to clamp down over the part. On the right is the redesigned hip hub with a much beefier seat for a much bigger shaft collar. The new shaft collar was something I had to custom make.

Turning custom shaft collars for the BNPF hip hub on my little vintage Craftsman lathe.

Turning custom shaft collars for the BNPF hip hub on my little vintage Craftsman lathe.

BNF57 LegStructure Bushings.jpg

In my new found paranoia about breaking plastic components, I was very concerned about my plan to press fit bronze bushings into my 3d printed parts. I am pleased to announce that, yes, you can press fit bronze bushings into 3d printed parts.

BNF53 LegStructure PressFitNuts.jpg

Here is a good work around for the fact that 3d printed parts cannot be threaded: press fitted nuts in hexagonal recesses. Works great!

Here are the finished leg assemblies.

Here are the finished leg assemblies.

Body Elevation Mechanics

Raising and lowering the body of the BNPF was accomplished with a linear actuator from C.K. Design Technology Inc.


It was during the construction of this part of the BNPF that my 3d printer started giving me problems. I had gotten most of the plastic parts I needed so I didn’t it slow me down and continued on using more traditional/old-school machining techniques. In terms of the levers, cranks, and clamps needed for this part of the project, there wasn’t much 3d printing was going to do for me, anyway.

BNF59 BodyElevateMech.jpg
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Head Mechanics

The head is a relatively simple yet critical aspect of the BNPF. It is actually made from a model of the jaws of a dragon fish. How cool is that?

BNF84 HeadDetail.jpg

The neck had to be completely installed and cabled before the head could be dealt with. There is a lot that goes into a 2-stage neck mech, especially if there is going to be a cable actuated head mounted on the end of it.

BNF79 NeckDetail.jpg

The Base

To facilitate bringing all the various elements together, the BNPF needed to be mounted on its base. I wanted this critter to stand stand fairly high in relation to the eye line of its viewers, so I chose to mount it upon a metal pedestal that was once part of a decorative lamp post. It is to be displayed in a group art show and these things need to be considered.


In addition to supporting the BNPF and displaying it to its best advantage, the base houses all the various electronics needed to bring this project to life (power, microcontroller, sensors, motor control) . So, it not only needs to be sturdy and look good, it’s interior needs to be accessible while the electronics are installed. The enclosure for the electronics actually required a surprising amount of work.

BNF71 BaseAssembly.jpg
BNF73 BaseElectronics Enclosure.jpg
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BNF83 BaseDetail.jpg
BNF75 AllCommingTogether.jpg

Power Supply and Enclosure

The electronics for the BNPF required two different power supplies and they needed some sort of decorative enclosure. I modified an old radio I picked up at a flea market to serve that purpose.

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The Control Electronics

As an art piece the BNPF looked really cool. However, it was meant to be an interactive, robotic art piece, and as such, it was less than ideal. The problem was that I was using a Basic Stamp 2 as a microcontroller and its capabilities were just too limited. At the time, it was the microcontroller I knew best. The inherent limitations of the Basic Stamp 2, as well as the fact that I had run up against the deadline for the art show, meant that its performance was less than satisfactory. Ah well.


The system I had put together to control the performance of the BNPF consisted of the Basic Stamp 2, a motion sensor, and an array of three sonar range finders. The idea was that the motion sensor would alert the Basic Stamp 2 of the presence of people, the array of sonar sensors would located the location of the nearest target within range, and then the BNPF would respond with some behavior appropriate to the direction and proximity of the nearest target. I have some success in the past with this exact system with animatronic tentacle creatures, but alas, the BNPF was just a bit too complex for it to work well. It needed to be able to respond to its environment with the same level of interactivity as a pet parrot on a perch, which it really didn’t.


I was discussing this situation with Jon McPhalen, who is a big proponent of the Parallax Propellor microcontroller and he has me convinced that the Propellor is the way to go with this kind of interactive, robotic sculpture. Microcontrollers like the Basic Stamp and the Arduino are capable of doing only one thing at a time:  check the sensors, move a servo position, move another servo position, check the sensors again, ect… not really what was needed. The Propellor has parallel processing, which basically means it has 8 individual processors working simultaneously. That means sensors could continuously be scanning the surroundings of the BNPF, servos could be going through complex little behavioral subroutines, and multiple emotional states could be qued up and ready to go once the sensory inputs indicated it was appropriate. Sound great right?


I know people who seemingly eat new computer languages for breakfast. I am not one of them. I have sat down a number of times with a chunk of time set aside for learning to program the Parallax Propellor in the Spin language, and every time it was a miserable experience. I found the learning curve for Spin to be brutal. The Brave New Pink Flamingo stands lobotomized in a corner of my studio to this day. So sad.

Test Circuitry with Basic Stamp 2

Test Circuitry with Basic Stamp 2


The Brave New Pink Flamingo (Part 1)


After that loonnng series of posts I just finished (Wonderful World of Tentacle parts 1 through 5) I thought it would be nice to keep this one short and sweet. This project I am about to describe features a tentacle mechanism, but I cover new information such as the the use 3d printed mechanical parts and how to strengthen printed parts with electroplating.

BraveNewPinkFlamingo Cropped.jpg

The Brave New Pink Flamingo was originally created to be part of the Conjoined 5 group art show curated by Chet Zarr at the Copro Gallery in Santa Monica. It was inspired by the tacky pink plastic flamingos people sometimes use to decorate their yards. “Wouldn't it be so much cooler if they were robotic,” I thought to myself, and so was born the Brave New Pink Flamingo.

BNPF Concept Art

BNPF Concept Art

Retro-Futuristic BNPF

Retro-Futuristic BNPF

BNPF Mechanics

BNPF Mechanics

The Concept

The original concept started off as a retro-futuristic-rocket-ship-looking robot flamingo featuring 3d printed pink parts. However, it evolved into something scarier, probably because I was binge listening to the H.P. Lovecraft Literary Podcast while I was building it. So it goes.


At the time, I was still getting to know my 3d printer and what it could do. I decided the Brave New Pink Flamingo (BNPF) was going to feature a servo operated tentacle mechanism. I like tentacle mechs because they are relatively simple yet can be very expressive. This was for an art piece so simple and expressive were desirable features. In addition to the tentacle mech neck, I wanted it to have jaws. A robotic sculpture with a long, sinuous neck and big, toothy jaws trying to bite people: how cool is that?


I had the opportunity to try out a new material: carbon fiber-filled PLA from Proto Pasta. It seemed like a good choice for mechanical components. I also experimented with electroplating as a way to strengthen and stiffen the 3d printed parts. Electroplated plastic works really well for mechanisms as well as art. Not only does it strengthen and stiffen the parts it gives it a beautiful and durable finish. Most of the animatronic art pieces I've done over the years have featured electroplating. I just can’t seem to help myself.


A microcontroller and an array of an electronic sensors were incorporated into the BNPF to give it some robotic interactivity. Animatronics for use in film usually involves an operator/puppeteer but as a stand-alone art piece I wanted this to be a robot, not a puppet. Alas, this was probably the least successful aspect of this project due to my limitations as a programmer. Improving my programming skills in order to bring the Brave New Pink Flamingo to life is still very much on my bucket list.

3d Printing the Parts

BNF03 NeckPartsPrint.jpg

All of the printed parts for this project we're created on Woody, my Type A Series 1 3d printer. One look at the photo will tell you why I named it Woody.  As a material for mechanical components, carbon fiber-filled PLA has some nice characteristics, primarily it's stiffness and it seems to warp less than regular PLA. However, the main drawback is the wear-and-tear the carbon fiber PLA inflicts upon all the metal parts of the printhead. I managed to get most of the way through two rolls of the filament before the little knurled wheel that feeds the filament through the hot end of the 3d printer was worn smooth. That's not a huge deal if one is prepared to replace printer parts on a regular basis for the sake of using carbon fiber-filled PLA, but I was still unfamiliar with the technology and I was up against a deadline. So, the experience of being in the final phase of the project and having all my prints unexpectedly turn into crap pretty much turned  me off to carbon fiber-filled filaments. I ended up resorting to more traditional machining and model-making techniques to finish this project. Specifically, the feet, the head, and the body shell are fabricated by methods other than 3d printing. They turned out pretty cool, but the added aggravation was not appreciated.

Post-Print Cleanup of the Parts

BNF02 PostPrintCleanup.jpg

A common misconception amongst people unfamiliar with 3d printing is that the parts come out of the printer in pristine condition. This is not the case. There is still a considerable need for what machinists call benchwork. In 3d printing there tends to be loose strands of filament, wonky edges where the parts were adhered to the print bed, and all the holes end up being a little bit undersized. These issues all require some trimming, standing, drilling, and filing. The great part about 3d printing mechanical components is how accurate the fabrication process is. The holes may be a little undersized but they all line up perfectly with each other. I love that.

BNF04 NeckPart BenchWork.jpg

Another underappreciated aspect of the 3d printing process is the characteristic texture that everything ends up with. There may be some really high-end machines out there that can make some beautifully smooth and flawless prints, but I don't own one of those. When I first started working in the film industry I was introduced to the concept of “if you can't hide it, feature it”. In the case of 3d printing, this means you should learn to love that funky texture because it is not worth the hassle of getting rid of it.

BNF08 Textures.jpg

Printer Problems

I was probably 90% of the way through the printing needed for this project when the prints began to fail. I didn’t realize it at the time, but the carbon-fiber-filled PLA really wears upon any metal components of the print head it comes in contact with. The benefits of using carbon fiber-filled filament are just outweighed by this fact, in my humble opinion. The filament strands are indeed strengthened by the addition of little chopped up pieces of carbon fiber but the inherent weakness between the layers of the printed part is not mitigated in any way. The junction between these layers are where the parts are weakest, so there is no real benefit gained by using the carbon fiber-filled PLA filament, though I have to admit, I do like the matte black color of the finished parts.

BNF45 PrinterProblems.jpg

The Machined Parts


As useful as 3d printed parts are, there are certain applications that require metal. Specifically, anything in the body of the BNPF that is going to have threads cut into it will be made of aluminum. Printed plastic parts can be tapped but it won't take too much tightening for a screw to just rip those threads out. There are certain applications where one can get away with that, but for the most part, I try to avoid tapping plastic.


For the BNPF project I turned some simple standoffs on a lathe for securing the various components of the body together. I probably could have used off the shelf threaded standoffs but a little lathe work seemed like a nice change of pace. Additionally, I drilled and tapped a bunch of small aluminum gear blanks for mounting the tentacle segments. The gear blank modifications in particular were a little labor-intensive: lots of little holes to drill and tap. For future 3d printed tentacle projects I have figured out different mounting techniques involving the use of heat set threaded inserts that eliminate the need for the gear blanks, but that is for another project.

Turning Aluminum Standoffs

Turning Aluminum Standoffs

Tapping Threads into Standoff

Tapping Threads into Standoff

Drilling Gear Blanks with Sherline Rotary Table 

Drilling Gear Blanks with Sherline Rotary Table 

BNF26 NeckMech Assembly.jpg

In addition to the aluminum standoffs and the modified gear blanks there are other mechanical components machined from metal. These were the parts involved with moving the whole body and needed to be particularly strong. We'll discuss these when we get to the body elevation aspect of the project.

The Pre-Assembly Process

BNF09 NeckMech PreAssembly.jpg

A pile of parts is pretty uninspiring. So I find it helpful and informative to assemble the components as they are produced, even though I know full well I'm going to have to take everything apart again. The fact is, the more complicated the mechanism, the more assembly and disassembly will take place. One of the guys who taught me how to do animatronics, way-back-when, told me that a project isn't done until you’ve taken it apart and put it back together at least 8 times. And 20+ years later I pretty much have to agree. It's best to keep it to a minimum, for the sake of one's own sanity, not to mention that of your employer, but a certain amount of it is unavoidable. But it's pretty damn cool to see your stuff coming together during that initial pre-assembly.

BNF12.5 BodyAssembly.jpg
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Servos were used to drive the neck of the BNPF. The servos I chose were three HiTec hs-805BB servos because they are strong, durable, inexpensive, and have nylon gears instead of metal gears. Nylon gears are not as strong as metal gears but they have better wear characteristics and will last longer if not put under too much load. The design of the 3d printed body framework is laid out so as to provide a place to mount the neck, hold the servos in place in relation to the neck, and to provide a structural pivot point for the elevation of the body. This should all become more clear as all the components come together. The elements of the body structure are designed in layers to facilitate the 3d printing process. The the aluminum standoffs connect these different layers together.

BNF15 BodyAssembly.jpg
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Once I am satisfied with how the various body and neck elements go together I then have to take it all apart for the electroplating process. Yay.

Electroplating Preparation


I have seen examples online of people electroplating 3d printed plastic parts but never for the purpose of making them more structural: only to make the parts prettier. I have utilized electroplating in the past with cast resin parts to make them both stronger and yes prettier.  There is a huge opportunity or making lightweight 3d printed parts more suitable for use in mechanisms, and now I am going to let you in on the secret.


Primarily, the individual components of the neck and the neck strut will be electroplated. These comprise the most visually dominant elements of the BNPF and would benefit the most from being strengthened and stiffened. Some of the other visual elements will also be plated but the neck and the strut are the most mechanically crucial parts to undergo the process.


Once the components are cleaned up, the first step of the electroplating process is to give them a coat of primer. I use an automotive primer as it is of a better quality than the more generic types of primer available from your local hardware store. After the primer is applied, a fairly heavy gauge (18 to 16 gauge) of copper wire needs to be attached in order to suspend the parts in the electroplating solution. The plastic parts will want to float in the plating solution so the copper wire needs to be strong enough to keep the parts submerged during the plating process. Then, a layer of electrically conductive paint is applied to the part. Electrically conductive paint is available from plating supply companies online.


I have found it helpful to apply the conductive paint with an airbrush for anything but the smallest objects. Airbrushing helps to apply the paint evenly but it can be tricky. The conductive paint needs to be thinned down enough to pass through an airbrush but not so thin that it becomes non-conductive. My approach to this is to thin the paint just enough to be able to spray it with an airbrush and no more than that. The texture of the paint can get a little stippled, adding some roughness to the final finish of the metal plate, but I have learned to live with it. The alternatives to applying the paint with an airbrush is to use a paint brush (very labor intensive and inconsistent) or to dip the parts in conductive paint (requiring a lot of paint).

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Electroplating 3d Printed Parts

Plating Station

Plating Station

My electroplating system does really well with copper. Copper is the base metal for any plating operation weather it is for gold jewelry or chromed hot rod parts. I allowed the copper layer to build up on the parts for about 12 hours.This creates a layer that is plenty strong for the purposes of the BNPF.

Part ready to be Electroplated

Part ready to be Electroplated

In it Goes

In it Goes

And Out it Comes

And Out it Comes

I also had a small amount of nickel plating solution that I thought I'd make use of, though the finish has never been quite as bright and shiny as it might have been. Don't know why, but it always comes out a little funky. We're making art here not a hot rod; I have embraced the funk. The nickel plate was allowed to go on for about 30 minutes. It came out of the plating tank looking brown and funky, but with some buffing with a soft wire wheel in a dremel tool it shined up fairly well. However, it still retained some of that funky stuff. In future projects, the funkiness increased to the point where the solution just became useless. Perhaps some chemical element was becoming depleted in the solution. Don’t know. Not worried about it. Moving on.

Nickle Plate Set Up

Nickle Plate Set Up

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Fresh From the Take Looking Brown ?

Fresh From the Take Looking Brown ?

Shined Up a Bit and Looking Much better

Shined Up a Bit and Looking Much better

Bunches of Parts for the Plating Tank

Bunches of Parts for the Plating Tank

Coated with Electroconductive paint

Coated with Electroconductive paint

Arranging Parts for Plating

Arranging Parts for Plating

In They go

In They go

And Out they Come

And Out they Come



Funky Brown Nickle Plate

Funky Brown Nickle Plate

Put Some Shine on it

Put Some Shine on it

I Dig the Textures

I Dig the Textures

This is Going to be the Sweetest Robot Flamingo Ever!

This is Going to be the Sweetest Robot Flamingo Ever!

If I Had It All To Do Over Again: The Thrashing Torso v.2.0

We live in interesting times.


3d printing is becoming a mature technology and can be very useful and making mechanisms. I once heard 3d printing described as a lifestyle enhancement. Speaking as someone who is tired of expending my valuable hours planted in front of a lathe or milling machine, I heartily agree.


Man hours are expensive. Robot hours not so much. The more work that can be delegated to some form of CNC (computer numerical control) machine, the better.


3d printing has its strengths and it has its weaknesses. The trick is to play up its strengths and avoid the weaknesses. Over the past several years I've been experimenting with 3d printing parts for animatronics mechanisms with mixed results. Sometimes plastic just won't do and metal fabrication comes back into the picture. However, there is a lot plastic can do.


The New and Improved Thrashing Torso:



Since I built the original thrashing torso, all those years ago, a few things have changed.


3d printing is one of these changes. Another change is the introduction of new off-the-shelf products meant for use in Halloween haunted attractions. I've recently been introduced to the Spider Joint from Spider Hill Prop Works. It is a versatile plastic joint used in conjunction with 1 inch pvc pipe to create body armatures. The new Thrashing Torso also uses a 12-volt motor from Frightprops, another haunted attraction oriented business. Additionally, a plastic halloween skeleton is used. Some modifications are required and this proved to be the most time-intensive part of the build.  


A few other refinements have been incorporated into the design. Bungee cord is used instead of springs and clothesline from the hardware store is used instead of steel cable.


All of these changes make the finished mechanism much easier to make, the parts are easier to acquire, and everything is much lighter.


The Breakdown:


Man Hours Required: ~30 hrs.


I spent about a half a day designing the mechanism in Fusion 360 and I estimate another half a day setting up for the 3d printing and cleaning up the parts as they came out of the printer. Only another day was spent assembling the mechanism. Modifying and mounting the plastic skeleton took the better part of two more days, which includes futzing around with clearances and tensioning the bungee cords.  Considering how much time the first Thrashing Torso took to build, this is great.


Cost: ~$158 (total)


    Plastic Skeleton $40

Plastic Skeleton Label


    Fright Props motor $25



    Spider Joints (x8)  $28

Spider Joint.JPG


    Misc. Components and Fasteners ~$40


    ABS Printer Filament Roll $25


Some Thoughts on 3d Printing:


There has been quite a bit of hype about 3d printing over the past few years. 3d printing is incredibly useful but let me come right out and say that it can be a pain in the ass. The technology is getting better and better all the time, but like any fabrication technique, it takes time to master. This is especially true when 3d printing functional mechanisms. In the next post (or three) I am going to discuss 3d printing and its applications to making animatronics, as well as some of the pitfalls you may be able to avoid.


My Introduction to Mechanical Design: the Thrashing Torso

The Trashing Sequence

The Trashing Sequence

The Mechanical Thrashing Torso was my first attempt at designing and fabricating a mechanical system for emulating organic movement. As such, it is a good starting point for a discussion about the creation of animatronic figures. The process I went through to create the Thrashing Torso is the same I've used ever since.

The Design Process:


The Mechanical Thrashing Torso could accurately be described as a single axis, cable-actuated tentacle mechanism with spring-assisted gravity return and a high-torque electric motor with a crank. That description is accurate but unnecessary. At the time I made the Thrashing Torso I was not familiar with most of these terms. However, I was familiar with the things like levers, pulleys, and springs, thanks to a childhood spent disassembling my toys and bicycles. This experience, plus a rudimentary knowledge of tool use and fabrication techniques, was enough for me to figure things out.

The design process for an animatronics figure can be broken down into four basic steps:

          -Establish Form

          -Determine Movement

          -Decide How

          -Make A Plan


The Form:

Form follows function is a basic rule of design. However in animatronics this axiom usually gets reversed. Typically, you are given a form and from it you figure out the functions. Whenever I've been called upon to create an animatronic figure the form has usually been decided upon and is presented to me as a sculpture or other type of concept art. This usually works out but it is important to keep in mind some fundamental rules of physics. For example, long spindly legs or giant wings may look great from an aesthetic standpoint but they are mechanically difficult to move. Leverage and mass dictate what moves and how. An octopus can’t gallop and giant flying dragons don't fill the sky. If there is not a good example of what you want to do in nature then it probably can't be done. Stick with what already works and function will follow form.


The Movement:

Once you have a thing you must decide what the thing is going to do. What do you want to move, how far, and how fast? The success of an animatronic project is largely a matter of movement quality. Quality movement is the movement that best pleases the eye and meets or exceeds the expectations of the viewer.


We are all creatures who have evolved surrounded by other creatures. We are all hardwired to respond to those other creatures in very fundamental ways. So everybody is an expert on how living things should move and behave. The animatronic creature needs to play upon that fundamental programming we all share. Is it familiar, is it new, threatening, or friendly? Reference photos and videos are invaluable in determining appropriate movement. Real life examples are even better.


Range of movement, speed of movement, and control of the movement are all determined by basic mechanical and biomechanical principles. You don't need to study engineering to learn how to use them but there are some basic laws of physics that can not be ignored.


The How:

In animatronics there are some tried-and-true techniques for achieving a desired performance. Cable control, servos, and direct physical manipulation (a.k.a. puppeteering) are all common means of moving animatronic figures. We will explore a wide range of techniques when discussing specific projects in future posts.


The Plan:

This may be as simple as where to start and how to end. Parts and materials need to be sourced and obtained. Then everyone involved in the project needs to be coordinated with in order to keep everyone on the same page. A simple project = a simple plan. A complex project with no plan = problems.


Mechanical Thrashing Torso: the Basic Concept


The mechanical thrashing torso was created to be part of a haunted house attraction for halloween. As such it needed to have three primary characteristics:

          -Be relatively simple

          -Be low maintenance

          -Have big, scary movements

The initial idea was to have a limbless human torso wrapped in plastic trash bags lie motionless until an unsuspecting victim passed by, at which time it would begin thrashing around. The garbage bag idea was discarded once it became apparent just how cool the mechanics looked by themselves. Perhaps the amputee in a trash bag was the scarier concept  but I decided to feature my handiwork instead.


The Thrashing Torso Form:

I used myself as the model for the Thrashing Torso. Measurements of my own anatomy determined the size and proportions..


The Thrashing Torso’s Function:

All that was required was to approximate the motions of a spasmodically thrashing human torso. One big cyclically repeating motion operated by a single electric motor. Simplicity is always best.


The How of Making the Thrashing Torso:

I am a visual thinker so I always start with a drawing. For the Mechanical Thrashing Torso I created a drawing of a human torso in two positions: fully erect and fully slumped. This served as a graphic representation of where the movement begins and ends. The spinal column was divided up into jointed segments that approximated the articulation of a human backbone.

The original working drawing used in the construction of the Mechanical Thrashing Torso

The original working drawing used in the construction of the Mechanical Thrashing Torso

The geometry of the spinal segments in the upright and slumped positions

The geometry of the spinal segments in the upright and slumped positions

In order to control the motion of the spinal column each joint needs a mechanical stop, limiting how far each joint can pivot. The physical stops in each joint define the configuration of the spinal column at the erect and slumped positions.

The movement of the spine is limited to a single plane (or axis) and each joint is limited in its range of movement. This allows the mechanical thrashing torso to move in a controlled way. Any more axes of movement and the thing will flop around like a rag doll.

Once the spinal column is assembled and the full range of movement is established, the length of the driver cable can be determined. Cable travel is the length of the pull required to move the spinal column through its full range of movement. Once the travel of the cable is known the length of the crank arm on the drive motor can be determined. The placement of the motor in relation to the torso should also be determined at this point.

When I build an animatronic figure, I find it is helpful to design only up to a certain point and then start building. If I try to design everything out completely, and then start building, all too often much of my design has to be reworked as the build proceeds. That is wasted effort. In the case of the Mechanical Thrashing Torso, I designed and built the spinal column, and then  figured out how the cable and motor would work to the best effect.

The Thrashing Torso Plan:

Not much to it. I had very little in terms of a budget, so for materials I scrounged up what I could and bought what I had to. The first thing to build was the segmented spine, followed by the base, the cable/motor drive system, and then the head. My plans always tend to be somewhat vague and consist of broad conceptual strokes. This because unforeseen issues always arrse and sometimes one must zig when when the original idea was to zag.

The Future of Animatronics


Like so many things these days, the field of animatronics is in a state of change. From the very beginning, animatronics was employed as an entertaining or even awe-inspiring spectacle. The Greeks are said to have place mechanized, moving statues of the gods within their temples to impress visitors. Disney really knocked people’s socks off when he introduced his animatronic Abraham Lincoln. Spectacle has always been a hallmark of animatronics and it is likely that will continue to remain true, to some degree or another. The immediacy and physicality of animatronics remains very useful in cinema, as it allow actors to interact directly and in real time with the animatronic figure, which cannot be done with a CGI character. Animatronics is alive and well in theme parks, and increasingly, in the haunted attractions that spring up across America every Halloween.


However, there is a technical revolution currently sneaking up on us called artificial intelligence (A.I.). There is plenty of debate about what A.I. is and is not, but, to a large degree it is already here. People have been talking to the intelligent personal assistants (IPAs) in their smartphones for a few years now,  and social robots are becoming increasing available on the consumer market. We are in the early days of these technologies, and the impact on the lives of people will be profound as they continue to develop. To effectively interact with people, these new artificial entities are going to need to move and behave in line with social expectations. Maintaining eye contact and conveying meaning through gestures and facial expressions are all going to be required elements of this technology, and this is where animatronics comes in.


Robotic personal assistants. Robotic pets. Robotic sex partners. The possibilities fairly boggle the mind. And animatronics can make it happen!

A Brief History of Animatronics

Classic automata

Classic automata

Walt Disney is credited with coining the phrase “audio-animatronics”, as applied to the mechanized figures which began to to appear in the Disney theme parks in the early 1960’s. Walt Disney was a unique visionary with the wherewithal to initiate and nurture a technology that would thrive for decades to come. Disney Imagineering continues to have a robust R&D department to this day.


The fact is, the creation of life-like mechanized animals and people has been going on for a very long time, and predates Disney by centuries. In 1515 Leonardo Da Vinci created a mechanical walking lion to present to the king of France. In the 18th and 19th centuries automata were a popular form of entertainment in the royal courts of Europe and in Japan mechanical puppets called Karakuri were used in religious festivals to reenact stories from traditional myths and legends. In the early 20th century mechanized figures forecast people’s fortunes in penny arcades and an animatronic galloping horse was featured in the 1939 New York World’s Fair.


It was in the 1970’s that animatronics creatures began to be utilized within the film industry, such as the mechanical shark in Jaws (1975) and elements of the costume created by H.R. Giger and Carlo Rambaldi for the movie Alien (1979). Animatronics in cinema truly came into its own during the 1980’s and one of the leading forces in its development was Rick Baker. The techniques developed by Baker and his team of artists and technicians greatly pushed the envelope in the realm of creature effects with his work in the films An American Werewolf in London (1981) and The Howling (1981). The newly developed techniques brought a whole new dynamic to the portrayal of fantastic creatures on the big screen that gave us many of the iconic movie characters we have today ( E.T. and the Terminator come immediately to mind).


When Jurassic park came out in 1993, the writing was on the wall for practical creature effects. Industrial Light and Magic had managed to portray convincingly life-like dinosaurs in a movie and no one had to physically build a thing. Animatronics has seen a steady decrease in application in cinema ever since.

Animatronics: What It Is

Contemporary examples of how animatronics are put to use.

Contemporary examples of how animatronics are put to use.

Wikipedia defines animatronics as “the use of robotic devices to emulate a human or animal or bring lifelike characteristics to otherwise inanimate object.” Whenever I need a concise way to describe what I do, I tell people “I make things move in an interesting way.” That seems to satisfy those who need some clarification of what animatronics is. It is a good explanation because it does sum up the ultimate goal of any animatronic project. We are living creatures and our attention is engaged by other living creatures. When an inanimate object exhibits lifelike behaviors, that engagement increases to a whole new level.


Animatronics borrows from across many disciplines and incorporates a wide range of methods and techniques to accomplish its goal of creating a lifelike performance. Puppetry, biomechanics, anatomy, robotics and mechatronics are just a few of the fields that contribute to animatronics. Before anyone gets the idea that animatronics is all technical and can be broken down into purely engineering terms it must be acknowledged that there is a very strong artistic element. The esthetic requirements must be met before any animatronic project can be deemed successful. The human brain has specialized in observing biological movement for a long time, and even if everything is completely sound from the biomechanical perspective, if it don’t look right it ain’t right.