I:  Designing R2-D2

A brief history of R2-D2

R2-D2 is one of the most memorable and lovable mechanical characters in film history. The compelling visual look, strong characterization, and ingenious sound design all conspired to create an endearing little robot that captivated audiences back in 1977, and still holds cultural currency today.

Writer/director George Lucas’ basic concept was that “astro-droids” such as R2-D2 were robotic mechanics or repairpeople, tirelessly fixing failed equipment across his fantasy galaxy. That's why they couldn't speak verbally except in electronic chirps and whistles – the droids, as Lucas dubbed his robots, mostly had to deal with other hardware.

INT. REBEL BLOCKADE RUNNER - MAIN PASSAGEWAY

An explosion rocks the ship as two robots, Artoo-Detoo (R2- D2) and See-Threepio (C-3PO) struggle to make their way through the shaking, bouncing passageway. Both robots are old and battered. Artoo is a short, claw-armed tripod. His face is a mass of computer lights surrounding a radar eye. Threepio, on the other hand, is a tall, slender robot of human proportions. He has a gleaming bronze-like metallic surface of an Art Deco design.

– Star Wars script, revised fourth draft. January 15, 1976

Unlike the shiny anthropomorphic “protocol” droids, such as C-3PO, astro-droids were squat and functional. They were mechanized yet sentient Swiss army knives, packed with tools and manipulator arms: perfect plot devices for getting our heroes out of various scrapes! They’re often called “astromechs” by fans, perhaps due to the term appearing in the Star Wars novelization, but they’re never called that in the original movies.

Screenshot from The Empire Strikes Back (1980)

Surprisingly, the two droids as characters have a very non SF origin. Lucas has often credited Akira Kurosawa's film The Hidden Fortress with inspiring R2-D2 and C-3PO. This Japanese classic from 1958 depicts the massive tides of clan warfare from the point of view of two ordinary bickering peasants, rather than focusing on generals or shōguns.

Feisty princess Yuki (Misa Uehara) with squabbling serfs Tahei (Minoru Chiaki) and Matashichi (Kamatari Fujiwara) in a scene from Kurosawa's the Hidden Fortress.

Star Wars likewise features a huge all-encompassing war, but we're introduced to the story by the lowliest members of society – a pair of argumentative mechanical servants. Structurally there’s a pretty linear narrative line to the first film. We first meet the robots, who take us to Luke, who takes us to Kenobi, who takes us to Han, who takes us to the princess and to the parallel story line of the bad guys. The two story lines then collide for the grand finale.

I think the robots are the centrepiece of the story in a way, because we're seeing the film – at least the first half of the film – through their eyes.

– Gary Kurtz, 2015

...I wanted to start and end the film with the robots, I wanted the film to really be about the robots and have them be the framework for the rest of the movie.

– George Lucas

In terms of the actual robot design, Douglas Trumbull’s 1972 science fiction film Silent Running was quite influential. It features a trio of squat, nearly silent robots engaged in repairing a crumbling spacecraft. Though none of them look particularly like R2-D2, they are also repair robots with extendable arms. (if anything, there's more of a connection to the “Gonk” power droids)

Trumbull took a remarkable approach to the design of his robots. To make them look completely unlike a person in a suit, Trumbull hired legless amputees who could walk on their hands. Using human performers allowed him to imbue his plastic boxes with a tremendous amount of emotion and pathos.

Screenshot from Silent Running. Freeman Lowell (Bruce Dern) communes with Dewey (Mark Persons) and Huey (probably Cheryl Sparks in this scene), two of the film's robots.

A droid on foot

The next major step saw Lucas hire American conceptual artist, and key Star Wars designer, Ralph McQuarrie in 1975. McQuarrie's initial role was to produce a handful of paintings to impress studio executives and thus sell the project, but he soon began designing everything imaginable – costumes, spacecraft, cities, and so on. He was joined by illustrator and designer Joe Johnston, who focused on vehicles and some environments. It's no exaggeration to say that the Star Wars universe we know today could never have existed without this incredible and imaginative art.

Ralph McQuarrie and George Lucas.

McQuarrie's earliest sketches of R2-D2 are fascinating in retrospect. The character below left looks somewhat similar to the final robot, but the minimalist character below right is particularly intriguing since it was designed to roll around on a single large ball bearing. This was basically impossible to execute technically in the 1970s, but of course has some interesting parallels to BB-8's design from 2015.

The first (one) had a spherical bottom, like a ball bearing that would roll around. He could go any direction - he had gyroscopes in him, so that he didn’t fall over. He just leaned into whatever direction he wanted to go in, and spun his single wheel, which is really a sphere. Which sounded pretty interesting, but very difficult to do in reality.

I put little panels on him and places for arms to come out. I knew he had to have a lot of little gadgets - that he was kind of like a Swiss army knife. And he had to have lights, and [...] lenses to see through. He had to have colour to distinguish him from another robot, so I found places to put blue.

— Ralph McQuarrie

Sketches by Ralph McQuarrie, from 1975-1976.

The later drawings and paintings, however, actually show the droid walking. This explains R2's somewhat inefficient industrial design, in fact. Because his legs pivot high up on the body, like a person's shoulders, his centre of gravity is also awkwardly high. This odd design makes sense if you think of him walking along like a person swinging along on crutches, which was the original idea. The anthropomorphized head and shoulders also make the R2 robots friendlier and more personable for the audience. Unfortunately the design resulted in some mechanical headaches when it came to building the real props, since R2 is a bit top-heavy and the motorized foot design isn't incredibly efficient.

For R2 I was looking for something different than the little robots [in] Silent Running, that Doug Trumbull had done. [...] I knew that our robots would be compared to their robots, because George had talked about them... He said, "those little robots in Silent Running… we want a little worker like that for R2-D2". And I thought well, instead of a box I’ll make him a can. A cylinder, with a dome on top. That was my first thought. Just strictly in the sense that I didn’t want him to look like Silent Running robots. [Those] had two legs, so I thought we could give R2 three legs.

— Ralph McQuarrie

This mysterious and haunting painting by McQuarrie, apparently the first completed for the production, shows a proto C-3PO, and a walking R2 making their way across the Tatooine dunes. There's a clear line of footprints behind R2 – those aren't wheeled tracks in the sand.

Production painting by Ralph McQuarrie.

Note the strange and disconcertingly human eyes and mouth on the golden droid. This was an early 3PO concept, and McQuarrie credited John Barry with coming up with the more neutral eye and mouth design used in the final robot. McQuarrie later reworked this painting with a different face, so if this version seems strange to you, that's probably why. Incidentally, Californians may recognize that the towering cliff face is modelled after Morro Rock, near San Luis Obispo.

We had superb production illustrations by Ralph McQuarrie, and as you know the film adhered closely to them. A lot of the credit is due McQuarrie, as the look of the picture was due to him.

– John Stears, Cinefantastique, 1978

This detail of a shootout in the cantina shows a familiar pair of droids lurking in the corner. This R2 certainly seems to have a busy head, encrusted with lights. Note the faint shadow above the dome. This suggests that originally he was painted as a taller robot, and then altered later to be much more squat. 

A variant of this droid appears in a draft poster design that McQuarrie painted in 1975. Luke was actually a young woman at this point in story development, and Han Solo can be seen wielding a "laser sword". The overall design is quite interesting, as it owes a lot to a Flash Gordon conceptualization of the story, rather than the gritty lived-in world that Star Wars eventually depicted.

Finally, here's a very interesting look at the droids. Lucas hired artist Alex Tavoularis to produce some of the early storyboards for developing the film. Tavoularis' style involved a lot of dynamic angles and an extremely stylized, almost comic-book-like, look. Threepio had a particularly dramatic and fluid sense of human-like motion in these drawings, and R2's design reflected aspects of McQuarrie's early sketches.

The name

First of all, R2-D2 never stood for anything, though some post-production marketing materials have created some ideas. There appear to be two origin stories for the actual name. In one version, mentioned in Star Wars: the Annotated Screenplays, Lucas simply made the name up because it sounded good. The other version is this:

...when I was mixing the soundtrack for American Graffiti with the sound editor, Walter Murch, we were working with a number of dialogue tracks and about twelve reels of film. Walter asked me to go to the rack and get R2-D2 – reel two, dialogue track two. When I heard that I thought what a great name that would be, and wrote it down in my little book. When I was developing the character of the little robot in Star Wars I developed it around that name.

– George Lucas in Bantha Tracks, the Lucasfilm fan newsletter. Issue 8 – spring 1980

Legendary editor and sound guru Walter Murch, holding the fateful reel.

Incidentally, I generally write the name in alphanumeric form because it saves me three keystrokes, but for much of the Original Trilogy the name tended to be written phonetically: as Artoo-Detoo. In at least one early draft of the script it was actually Artwo-Detwo. Artoo is also how the name appears in both the final script and the novelization ghostwritten by Alan Dean Foster and credited to Lucas.

Generally the specific robot is named Artoo, whereas generic droids of the type are "R2 units". C-3PO is written as See-Threepio. Less commonly, R5-D4 is even listed in the US trademark application as "Arfive-Defour", which was a name apparently used on some toy packaging.

Funnily enough, the original release of Star Wars had different character names for different languages and markets. R2-D2, for example, was flipped around and became D2-R2 in La guerre des étoiles in France. C-3PO was Z-6PO, Darth Vader was Dark Vador, Han Solo was Yan Solo, Chewbacca was Chiktabba, the Millennium Falcon was le Millénium Condor, and so on. French wasn't the only language that inflicted name changes. Darth Vader, for example, was Lord Fener in Italy. The Millennium Falcon was der Rasender Falke in German. The original English names were restored to many markets by the 1990s.

Defining a Robot

The next stage was to transform McQuarrie's drawings of R2-D2 – and other mechanical effects such as the landspeeder and the light sabres – into physical reality. The trick was to turn the sketches and paintings into detailed plans that could be built by a small team of technicians. Lucas was adamant that the robots and other props had to look convincing. The audience had to believe that they were genuine working devices from a galaxy far, far, away.

It's easy to forget how revolutionary the Star Wars production design was at the time. This embarrassingly shonky robot is from Logan's Run: released just a year before Star Wars. A man inside a mirrored box, equipped with a crude face mask, was apparently supposed to look futuristic.

By summer 1975, British special effects expert John Stears was on the job as special mechanical effects supervisor. Stears is not well known today, despite being one of the Oscar winners for Star Wars, but in the mid 70s was an industry veteran. He had an early career as a matte painter and model builder, and was famous for his gadget and prop work on the James Bond films – winning his first Oscar in 1965 for effects work on Thunderball. Conveniently for Lucas he was also a “powder man” with a pyrotechnician's licence – perfect for making walls blow up when hit by a blaster.

John Stears lies on the Tunisian sand as he controls the RC R2, which is rolling along on plywood sheets.

Incidentally this image, and many others in these articles, is a still frame from material shot by documentary filmmaker Peter Shillingford. He was hired to produce the behind the scenes Tunisia and England footage, what he calls the "film about the film," that appears in The Making of Star Wars and many other documentaries. It was shot 16mm colour, but sadly mostly without sound since the production team couldn't afford the requisite location sound recordist who would have had to accompany the camera. Shillingford was assisted in Tunisia by Mike Shackleton, who also worked with the first and second units at Elstree.

Another key hire was the legendary John Barry – not the English film composer of James Bond fame, but the English production designer. He started in autumn 1975, and was instrumental in the creation of the rich, lived-in set and prop designs that Star Wars is known for today.

The team responsible for Star Wars' real-life look. Set dresser Roger Christian in 1970s rock star mode, art director Leslie Dilley, production designer John Barry, construction manager Bill Welch, and art director Norman Reynolds.

But a little-known fact is that Barry technically wasn't the film's first production designer, since 20th Century Fox’s British managing director Peter Beale had hired art director Elliot Scott to consult briefly on the film and produce a preliminary budget for the complex and costly production. During his two week stint Scott brought in John Stears, who thus was the first full-time British hire on the movie, starting work on the first of August, 1975. This was even before George Lucas had flown out to the UK. Not long thereafter producer Gary Kurtz hired Barry and art director Norman Reynolds, and things kicked into gear. (Barry visited the US for meetings on 20 August and Lucas went to the UK in September)

John Stears (left) and his team ponder a recalcitrant radio-controlled R2 on the Tunisian dunes in 1976. From footage shot by Peter Shillingford.

The earliest work, in late 1975, was done at two temporary locations. Lucas and Kurtz were based initially out of the 20th Century Fox offices in Soho Square, London. And a small production team moved into Lee International Studios on Kensal Road W10 in North Kensington, London, and started prototyping key designs. The site was a “four walls” facility, meaning you could just rent the space without having to use studio staff. (the building, just east of Ladbroke Grove and Kensal Green Cemetery, is now sadly gone)

A lot of people contributed elements to the final R2 design, starting with Ralph McQuarrie's paintings and sketches. John Stears, Norman Reynolds, Roger Christian, Les Dilley, John Barry, and others all pitched in with ideas, with George Lucas as the final arbiter. Like everything to do with movies, the finished droids were a mixture of boundless creative design and physical, budget-restricted, reality. The decision to abandon the crutch-walking idea and make him a wheeled robot was likely made around this time.

The McQuarrie sketch below shows how a small performer could fit within the droid body in two-legged mode; the approach ultimately taken with Kenny Baker. It also shows how the droid would move on wheels when in two-legged mode.

Note that some of the leg and shoulder details differ considerably from the finished droid, which also lost the dome antenna detail shown in the middle. The retractable "fairings" were replaced with flexible hoses, but the 18" body barrel diameter remained almost the same. The hemispherical head later became ovoid, of course.

The wooden prototype

The next stage was to create a rough full-sized mockup as a proof of concept. It was clear by this point that R2 had to be a human being inside a costume, so the physical dimensions of the droid were essential to establish. They needed to know the height and width of the barrel, and how the robot's feet would fit those of a human performer.

And so it came to pass that set decorator Roger Christian and carpenter Bill Harman went down in history as makers of the first incarnation of R2-D2 in a physical form. The momentous event occurred at the aforementioned Lee International Studios; a grandly named but scruffy and rat-infested building on the southern banks of the Grand Union Canal.

I hired a carpenter – Bill Harman – who'd made all the props for Monty Python. He was brilliant – you could give him anything and he'd make it work. We had no money, not even enough to buy timber, but Bill had marine plywood at home, which he bent around the frame we'd built. In an electrical store, I found an old lamp from the 1940s and fitted that on top. I carved the little moving prongs on the front, and we stuck some aeroplane bits on and got him approved.

— Roger Christian, Cinema Alchemist, 2016

The version above is actually the second one that Harman built - the first one was deemed too wide, was never completed, and is now lost to history. In fact, in a phone interview Harman said it ended up in the canal. This second mockup was the smallest that could be built and still accommodate a certain performer named Kenny Baker.

There are a lot of fascinating things about this prototype. First, it’s remarkably close to the finished R2 design in many ways. Tons of tiny fiddly details, like the shape of the ankles, the arrangement of ribs on the “skirt,” the presence of half moons on the feet – it’s all there already!

Second, R2 already has his characteristic dome. And the reason it gained this unique shape was fortuitous happenstance. It wasn't possible for Harman to make a dome quickly and cheaply out of wood, so other options had to be considered. The small studio that the Star Wars team initially rented was owned by John and Benny Lee’s Lee Electric, the largest movie lighting company in Britain at the time. And the dome was actually the reflector from a decommissioned Lee Electric 1000 watt lamp that Christian found in a scrap storage room (the “electrical store” mentioned in the quote above referred to storage, not a retail shop). According to Christian, Bill Harman paid Lee's studio manager a princely 10 shillings (half a pound; though it's odd he should specify shillings since the UK went decimal in 1971) for the lamp. You can see earlike bits of metal in the photo above – those are the original lamp's handles or brackets.

Amazingly, despite all the changes and new droids over the years, the semi-ovoid and non-hemispherical proportions of this ancient and forgotten piece of lighting equipment still live on today in the shape of R2-D2's head! The only real change in shape was the addition of the two neck rings.

Third, the pale green holoprojector on the front left side of the dome, was an aircraft reading lamp found by Roger Christian. It came from a Vickers Viscount plane, but wasn't the same model of lamp that was built into the final droids.

The screen-used droids had grey-painted lamps, used on a different era of Viscount, which differed in geometry and construction from this green one. (for everyone who thought Christian was misremembering when he described finding a box full of green airplane reading lights, this photo suggests he was right!) Incidentally, parts of the final grey lights also show up, upside-down, on the Millennium Falcon and X-wing fighter dashboards.

Finally, note how the horseshoes on the shoulders are located on the inside of each leg in this design. This was also the case in the initial blueprints. However, the team made a last-minute change during development and switched the horseshoes to the outside, which is where they are today.

The move to EMI

Fox's board finally and reluctantly greenlit the show in mid December 1975. By that time production had already moved to EMI Elstree Studios in Borehamwood, north of London. Elstree was where most of the film's live action photography would take place, and where almost all the props and costumes were created. The quintessentially English studio may have seemed an unusual choice for an American film to be made. But at the time it was able to offer eight large sound stages, and like Lee International it permitted the Star Wars operation to assemble its own technical crew while also providing access to excellent facilities. The crew was thus a mix of people hired by Star Wars, and employees of EMI Elstree. Also, Britain was much cheaper than Hollywood, and had relatively easy access to Tunisia (three hours by plane) for filming most of the desert sequences.

It was at Elstree that a third known prototype was built - a rather strange-looking fibreglass version. This version was crude, but helped finalize the dimensions that would fit Kenny Baker's body.

Finalizing the designs

Next, the team had to nail down the basic designs on paper. Like any major film production, Star Wars relied on a series of detailed blueprints to guide the set and prop builders. They were hand-drawn by highly skilled movie studio draftspeople (or draughtsmen as they were known in the UK at the time) at EMI Elstree, under the close supervision of the Star Wars art department.

Here's a well-known blueprint of the near-final R2-D2, drawn by Peter Childs, one of five EMI draftspeople who worked on the film. (he was also a model maker on 2001: a Space Odyssey)

It's pretty well the R2 we all know and love, and only truly obsessed fans will notice the minor differences between the remarkably elegant and precise blueprint and the finished droid. (I think there are around six) The mechanical precision of these blueprints, hand-drawn in a pre-CAD (computer-aided design) era, is quite impressive.

Peteric - the unsung heroes of the Full Metal R2

Finally, when it came to building the R2 externals, John Stears hired a small English engineering firm named Peteric Engineering to do the work, because he wanted the droids to be built from metal. Much of the complex technical construction was thus done by external engineering contractors, not by filmmaking staff at the studio itself.

John Stears’ drawing below shows what he wanted. It indicates that two “hero” units for Kenny Baker to operate were planned, and a single radio-controlled/RC droid (the “mobile tri-leg” one) was intended. A fourth unit was designed for Baker to operate arms and so on for closeups, two were empty shells free of either motors or performers for certain stunt uses (strapped to the landspeeder and sucked into the sandcrawler), and one was a partial unit for the fighter cockpits. There is no photographic evidence that I’ve seen showing the last half-droid, however. It’s possible that a seventh droid was built as far down as the bottom of the body barrel, rather than halfway down the body, but we do know of many different droid domes that were made.

Peteric were based at Shepperton Studios on the outskirts of southwest London - diagonally across the city from Elstree. (Shepperton is where the rebel hangar and awards ceremony sequences were shot, incidentally) The majority of the original Star Wars R2 droids had domes, frames, and exteriors entirely built from sheet aluminium – they didn’t use “aluminum” without the letter “I” since they weren’t built in the USA! The metalwork bill ran to £18,000 – roughly £115,000 or $145,000 US in 2024 money; a not inconsiderable sum for the cash-strapped film.

To make the body barrels the crew took flat sheets of 1mm aluminium alloy (we don't know the specific alloy type), marked out panel locations from the blueprints, and punched out holes using a then high-tech Strippit punch machine. Peteric's managing director David Watling said in a 2013 interview with Brandon Alinger, “we had some machines that would punch holes very accurately within a few thousandth of an inch, in the flat material, and then you would roll it and join it.” He also added, “we had a tooling facility, which allowed us to make those punches and dies, so if we wanted a strange shape, we could make it.”

Another key person in the story was Jack Swinbank, a highly skilled metalworker employed by the firm. According to Watling, “Jack was one of the finest sheet metal workers I have ever come across, and he would be able to tell you exactly in the flat (ie: on the flat metal surface), where to make a hole, so that when you bent it, it came in at exactly the right place.”

The bodies were welded together to form a strong seamless barrel - not an easy trick to accomplish, given how thin the metal was. In fact, the accuracy of this complex work clearly reflects the skill and experience of the people who worked on the project.

The legs, dome, and feet were also crafted in metal, but were based on measurements taken from cast plaster references sent to Peteric from EMI. In other words, because the legs and feet weren’t dimensioned on the blueprints, Peteric took calipers to the casts and used that data, now lost, to construct the metal versions.

Sadly Peteric did not retain any of the blueprints, models, and records of R2's construction for posterity. It’s a shame, since it means that their important contribution to science fiction history (they also worked on Alien, designing and building a never-used mechanical jaw and head) is nearly lost and mostly forgotten today. Especially since other individuals and firms have regrettably taken credit for building R2-D2 over the years.

Almost all the droid parts were designed and custom-made. The hologram projectors, shoulder buttons, and eye lenses were probably the sole “found” parts on the robot’s exterior. Here are some more shots of shiny all-aluminium R2 units under construction at Peteric.

The battery boxes attached to the feet all had holes cut out of the inside edge in these shots. In the case of the Kenny model it's so that Baker could put his feet into the R2 unit's feet. (actually – into a pair of rubber boots) However, the radio-controlled (RC) droid had the same holes to accommodate the projecting motor mechanism. The RC droid just had curved panels made from thin sheet metal to cover the holes.

The photo below shows an early camera test of one of the Kenny R2s. Kenny Baker is visible inside - you can see his back with his criss-crossed suspender/trouser brace straps, and his right foot in a white boot. Also apparent is how the droid is made of metal, except for the white fibreglass feet and battery boxes.

The domes

All ANH R2-D2 units had metal domes made by Peteric from spun aluminium alloy. This means a flat sheet of aluminium was pressed into a dome shape by turning it against a wooden "former". As noted above, the shape and curvature of the dome were modelled after the old stage lamp found by Roger Christian. R2 doesn't have a hemispherical dome like the early sketches and paintings, but one slightly stretched vertically into a part ovoid.

Peteric's David Watling has said that each head consisted of two domes - an outer visible dome, and an internal support dome. This dual-dome design is basically the system used by hobbyist R2 makers today. Curved metal panels were then hand cut to fit each panel opening.

Note that there is some variation in the various panel holes on the original ANH domes. The RC R2's dome had panel holes which basically matched the blueprints. However, some of the other droid domes had subtly different panel hole locations. They were sometimes slightly further apart, or in the case of the holoprojector hole, aligned slightly differently. This is because each dome was made by hand, and it's entirely possible that different people were responsible for measuring and marking out each dome.

Watling also said that they were supplied with a cast plaster dome as a model for the dome; believed to be the one shown in the auction photograph below. The plaster is covered with handwritten measurements to be transferred over to the bare metal dome for marking. Note how the holoprojector is closer to the PSI panel than to the opposite blue panel, indicating that this off-centre look was the designers' original intent, matching the blueprints. The two logic lights are also not centre-aligned vertically within the panel – the gap at the bottom is larger than at the top.

Intriguingly, the pencilled text on the left reads "2? HEADS ALL PANELS REMOVABLE EXCEPT THOSE MARKED 'X'". However, it's not clear if that reads "3" scratched out and replaced with "2", or "20". I suspect the former. No droid in ANH was seen with an opening panel, though interior photos clearly show that one or two of the domes were built that way. The symbol "CL" is presumed to mean "centre line."

Dome neck mechanics

Incidentally, the mechanical arrangement of the ANH droid domes has been the source of confusion for a long time. Essentially how it worked was the metal dome had two visible rings at the base – one bare metal, and one blue.

The bare metal ring was attached to the body barrel assembly, but could rotate independently of the body barrel's position. In the second shot below you can see three trapezoidal brackets. These brackets, which had nylon slides on them, prevented the bare metal ring from being lifted off, but allowed it to spin freely. Finally, the bare metal ring had three positioning pins, which fitted into mating holes in the base of blue ring. This simple gravity system allowed the filmmakers to remove the dome instantly as required. The damaged droid in the post-battle hangar scene has a dome that's been dislodged and offset from its body - you can see one of the pins sticking out in the actual movie!

The blue ring was permanently part of the bottom of the dome, and had holes to match the pins. The dome would simply sit atop the metal ring, and was held in place by nothing more than gravity and alignment of the pins. The body's bare metal ring, the dome's blue ring, and the dome itself all turned as one group atop the body.

The stunt droids capable of toppling had threaded bolts, instead of pins, so that the domes wouldn't fall off. These had to be accessed via the back door of the body barrel.

C&L

A small company called C&L Developments, located just south of Shepperton in Weybridge, Surrey, were subcontracted by Peteric to perform the machining and the mechanical work. This included the final integration of the motors and other moving mechanisms in the RC R2. C&L's Neil Anderson worked on the RC R2's complex leg-drop mechanism. Peteric's Watling has said that C&L worked on many of these parts since Peteric did not have all the necessary machining equipment.

The leg drop mechanism

The RC R2’s middle leg was released by a servomotor, and dropped down on a dampened spring mechanism. In other words, the motive force for the descent came from a bank of springs at the top of the body, and the descent was slowed as it neared bottom through the use of a hydraulic dampening device. This was a “dashpot” manufactured by British engineering firm Kinetrol – a product still sold today! A separate bank of springs powered the outer leg tilt motion.

Incidentally you sometimes hear that the original droids used "pneumatic" mechanisms. None of the OT R2s were built with pressurized gas or air systems for leg control. However, years later at least the ANH RC R2 was retrofitted with a pneumatic leg, almost certainly during the prep work for Episode I at Leavesden Studios. Also, the original ANH R2 wasn’t what fan builders call 2-3-2 capable: the RC R2 could lower its middle leg but couldn’t raise it. The leg locked in place as it descended and the operators had to lift up the dome, reach in, and reset it. All while moving the legs back to their 2-leg position.

They could have simulated the leg-raise effect by doing a leg lower and then making the film run backwards, but it seems they never did. Whenever R2 transitions from 3 legs to 2 in the first film he does so basically off-screen, or he tilts forward and you can't see his feet.

Unfortunately, according to Neil Anderson of C&L in a 2020 conversation, the RC R2 droid was damaged in shipment from the UK to Tunisia. The cargo plane had a rough landing, and the middle leg mechanism bore the brunt of the damage, resulting in a leg that failed to catch on the first day of shooting.

A polished droid

Once the mechanicals were integrated, the EMI studio art department was responsible for painting, according to Peteric's Watling. Sadly, we basically have no photos of this part of the build, which occurred during the final frantic days before the droids had to be air-shipped to Tunisia for the first day of filming. We thus have no studio photos of gleaming white and blue metal droids, prior to weathering. The closest we have are a couple of shots taken in Tunisia, such as this one.

We also have this shot, which was actually taken as part of a promo shoot for the 1-year anniversary of the movie's release. The full image shows C-3PO, standing next to him, holding a cake with a single candle. Aside from the general weirdness of the "radar eye" being backlit in red, and the logic lights being lit with yellow rather than blue light, it's quite an interesting photo.

The robot looks extremely clean, unblemished, and almost new. The panel lines are all crisp and sharp. Especially compared to the ones touring the world, which look pretty beat-up. The droid has open battery boxes and skirt, suggesting it was a Kenny droid. But it has no rollerskates on the underside of the feet, and certainly no hint of a wheel. And the right leg is button-back, which is odd.

I've no idea why this one looks so good, given that the picture was taken so long after filming completed. Regardless, these shots are probably the closest we can get to how the R2s looked, freshly built.

Background ANH droid domes

The background droids, which had different colour schemes from R2-D2, had unique heads. These appear to have been cast in fibreglass using a mould derived from the plaster dome above. In fact, there are obvious dents on the plaster form, presumably reflecting the studio lamp used as its model. And these dome dents were faithfully duplicated in glass-reinforced plastic!

Generally if an ANH droid has a fully-painted and non-metallic dome you know it's a fibreglass one. The non-R2-D2 droids shown behind the X-wing and Y-wing pilots during the final battle sequence were all simply domes made this way. Finally, it seems two R5-style heads were also made of fibreglass.

The robotic R2

John Stears was keenly interested in building an actual working robot; one capable of performing. He is said to have visited academics and researchers to try and enlist their assistance. In other words, he didn't want to just cobble together the bare minimum that looked acceptable on-screen. A man with ambitious plans indeed.

Conjecture: this approach, while admirable in principle, was definitely incompatible with the general lack of time and budget suffered by the first film, and may have been the underlying reason why the 1976 robots had such technical problems. In a sense Stears was ahead of his time, since modern films and TV productions use a lot of computer-controlled mechanical effects in addition to computer imaging. Unfortunately, the delays inflicted by Fox's refusal to commit to the project officially until December 1975 also cost the production dearly.

In the end, fully robotic R2s were not possible, both in terms of budget and available time. Stears had to be satisfied with all-metal robots largely worn as costumes or occasionally puppeted externally. Only one robot was built with mechanization, and that radio-controlled R2 simply had driving motors in its outer feet, a steering mechanism in its middle foot, and a spring-loaded middle leg mechanism. It couldn't turn its head or operate its arms.

It was Stears and his effects team who worked on the mechanisms of the RC R2, and the lights built into most of the droids. According to Stears in a 1978 Cinefantastique interview, his crew included “Dick Hewitt, electronics expert; Brian Warner, Bert Hamilton-Smith, Bob Nugent, all engineers; (and) Bennie Smith, electrician.”

Stears was quite upset that none of the people who worked on his end of the show were listed in the film's credits, grumpily remarking that "the American crew credits included everybody including the teaboy, but my effects crew never got a mention." Accordingly he placed a full-page ad in Screen International, a British industry magazine, thanking the people and companies who worked on the project. Note that this ad doesn't just focus on the people who made R2-D2, but also people who worked on the landspeeder, the dewback mannequin, the light sabres, the non-R2 droids, and so on.

Plastic droid

In addition to the all-metal radio-controlled droid, and the two Kenny metal droids with fibreglass feet described above, there were also droids built entirely from synthetic materials. In an interview broadcast in 1978, producer Gary Kurtz says that "two or three were made out of fibreglass." This view of a workshop shows EMI studio technicians working on moulded droid components.

Fibreglass parts being made, probably at EMI. The mould at front right was used to create a leg and a shoulder as a single part. The man at the back is working on one of the two halves of the fibreglass body barrel for R2. Most likely from footage shot by Peter Shillingford.

At least one of the all-fibreglass droids saved the day in Tunisia, since the empty shell could be pulled around when the complicated motorized three-legged droid failed. This low-tech method is how much of the R5-D4 scene was filmed for the droid auction.

John (Barry) called Les (Dilley) and me into his office and shut the door. He told me he’d been to John Stears’ workshop and looked at his remote-controlled R2-D2s, and that he thought they weren’t going to be ready in time for the first day’s shoot in Tunisia.

So John Barry had Les and I prepare a secret R2-D2 that no one but us would know about to take to Tunisia. We prepared a lightweight fibreglass version, fully dressed and functional. We would rely on pulling it around using the tried and tested way of nylon fishing line.

— Roger Christian, 2016

How many droids were there in Star Wars?

It may seem a straightforward question, but it’s actually quite complicated. Basically as far as I can tell, nobody knows for certain anymore exactly how many R2-D2 props were constructed for Star Wars (1977). In fact, how is that even defined? The number of domes? Of bodies? Of full units?

Complicating matters further is that the various components making up R2 have been mixed and matched from year to year, from film to film. A droid on public display today might consist of an ANH body with an ESB dome. Some of the prequel droids were built from scratch for the film, but some were actually reworked Original Trilogy droids. Here's what I've found so far.

The John Stears diagram refers to 6 full droids and 1 half droid, though since the sketch was from early in the build process it's uncertain if that was the final number produced for the film, and it seems unlikely that a half droid was actually built. The number 7 was corroborated by Peteric's David Watling in an interview with Brandon Alinger in 2013. Watling said that “about 10” domes were built, but added he doesn't remember exactly how many.

Gary Kurtz, in a 1978 interview, said that "8 or 9 droids" were built, and adds that 2-3 were made from fibreglass. An auction of a pre-production plaster head via the Bonhams auction house claims that 7 droids were built.

This production memo talks about 10 R2s. It's not, however, clear how that is defined. Do they mean complete droids? Do they mean body shells and domes? Does it include the fibreglass droids? Does it count R5-styled droids? Are they also counting other prop droids like the Treadwell and the big standing droid?

This location photo in Tunisia shows at least four astro-droid bodies were present on set. Since all the droids are still beautifully clean, pristine, and undented it's clear the photo was taken before filming began. It looks like the left-hand one is the motorized R2-D2 (three wheels plus head electronics), the next one is a Kenny R2-D2 (the holes in the battery boxes and only two legs), the third one is an R5-D4 head atop an R2-D2 two-leg body (blue utility arms, plus the door above the coin slots has no recess), and the unpainted one on the right edge is clearly a plastic or fibreglass moulded shell, not a metal body. In addition, we know from other photos that both Kenny droids were present in Tunisia.

Here's an empty fibreglass shell being hastily converted on-site to play R5-D4; probably for the roll-out and bad motivator scene. At this point many of the metal details are missing. The under-shoulder details are on the table, waiting to be installed. Notice an important detail – the small horizontal door above the coin slots that has the R5 recess to it. Notice also the wooden frame, used during construction to hold the body back in the correct 18° position for the tripod mode. The R5 from the previous photo stands in the background. 

In addition to the background droids used in Mos Eisley, aboard Princess Leia's ship, and on the Death Star, there were also the droid heads made for the X-wing fighter scenes. Most of these droid copilots were little more than moulded fibreglass heads, painted a variety of colours and in a number of schemes. The thrifty production even used a black-painted fibreglass R2 droid head as a basis for the floating torture robot that Darth Vader uses on his daughter.

In a 2003 interview Don Bies, droid wrangler for the prequel films, said that there were 15 Artoos in those movies. This includes both modified OT droids, and the units built specifically for the prequels.

So here's a summary of my best guess. In 1976 there were 1 metal three-leg R2, 5 metal two-leg R2s, 1 metal partial R2 (maybe), 1 three-legged fibreglass R5, and 2 two-legged fibreglass R5 built, for a total of 10. This is conjecture based on the research above, and assumes that the number of metal droids wasn't reduced when the decision to make all-fibreglass droids was made.

The patent

In September 1977 Twentieth Century Fox filed a US design patent (USD251628S) for an "ornamental design for a robot". It was assigned in 1979. This has now expired, but the fact they did so is interesting, reflecting as it does the massive commercial value of the property. The inventors are listed as Ralph McQuarrie and John Stears. Sometimes this drawing is incorrectly referred to as a "blueprint", when it's obviously not. It is worth mentioning, however, that this patent is for the overall look of the robot, not for any particular mechanism or mechanical implementation.

The names "Artoo-Detoo" and "R2-D2" are also trademarked in the USA for the "action figures and accessories" class.

Old Rivet; the ANH RC R2

And here's a famous publicity shot of the original tripodal radio-controlled R2-D2 from Star Wars. Pretty beat up from months of filming, and hastily bolted and riveted together in places! This droid is sometimes referred to as "Old Rivet" by fans. I usually call it the ANH RC R2.

The photo was taken in Hollywood by famed American rock photographer Bob Seidemann in 1977 after the film was released, as part of a series of promo shoots of the original cast. Much of the cast, anyway. R2-D2 was represented by this radio-controlled droid, not by Kenny Baker in a costume. Darth Vader was portrayed by Kermit Eller and not David Prowse. And Alec Guinness and other cast members were not present.

The key point is that the droid in the photo below is not as it appeared during filming, but during the post-production period when it was called upon to make media appearances. Its condition in these pictures represents the rigours of filmmaking, plus the repairs and modifications it underwent at ILM in California.

There are a number of interesting points regarding this particular robot.

• This is clearly the RC droid that was seen at the start of the Blockade Runner opening sequence – its body is covered in rivets or screw holes.

• Angle brackets have been bolted on to prevent the spreading leg problem that plagued the ANH three-legged R2.

• The angle irons also mean that the innermost pair of decorative battery brackets (the vertical silver strips with small blue tabs) have been removed from the battery box, and the outer ones are closer to the edge.

• Notice how the top front edge of the middle foot has a pair of dents in it. This clearly shows where the ankle slammed into the foot when the robot faceplanted during filming!

• There are semicircular bare metal pieces on the lower section of the battery boxes, where the cables join.

• There are visible screws and pop rivets all over the feet.

• There is an obvious sheet metal piece curved over the top and upper side of the battery box, covering the area where Baker's feet would have gone on the two-legged droid. It looks like they made battery boxes for both types of R2 units, and put a cover over the RC R2's hole. The metal sheet also had a gap where the RC unit's motor stuck out slightly.

• There is a small protruding object on the lower edge of the "radar eye". It looks very much like a tiny toggle switch, presumably used to turn on internal lights or something. This switch is not visible in any film footage, and thus may have been added after filming ended.

• The front holoprojector surround appears to be black. However it's blue in some scenes in ANH, but silver-grey on all the ESB R2s.

• The middle foot has two noticeable holes on the front. These holes are not present in any shot in the movie, even the pickups. But they're visible in all the post-movie appearances. So it seems they were added sometime in the middle of 1977 for unknown reasons.

This is just a brief list of some of the unusual points about this robot. Check out the list of first and second gen droids for more details!

On to part II: the Astro-droids of 1977.

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