IV: Naming the Parts of a Droid
Here are the commonly used names for various parts of R2-D2.
So. Are these names official, per se? Not really. The parts aren't really mentioned in any of the scripts. The original novelization by Alan Dean Foster makes reference to a handful of details. The original blueprints drawn up during production of ANH identified parts by functional codes or names, not descriptive terms. And the pack of blueprints published by Ballantine in late 1977 has a few name labels added onto the R2 diagram.
As a result, most of these part names come from amateur builders and fans.
This front photo was taken by Bob Seidemann in mid to late 1977, and is the original radio-controlled R2 unit used in the first film. There are minor differences seen in later R2 units, but the names mostly stay the same. Finally, note that a number of popular names for things derive from later movies, not from Star Wars/Episode IV itself. This is because some of these features are not seen in use except in the ESB/ROTJ, or indeed the prequels. For example, the blue bar details on the legs are called "boosters" strictly because of the rocket feature added in the prequel films. R2-D2's functionality changed as the series of films went along.
1 Dome / head on blueprints
2 Pie panels / access panels / dome panels
3 Radar (sic) eye / radar eye lens
4 Radar eye surround / radar eye / primary photoreceptor faceplate
5 Data slot
6 Front logic displays (FLD) / front logic lights / “flashing optics panel” on blueprints
7 Front process status indicator (PSI)
8 Front holoprojector (HP) / hologram projector / holographic projector / “ball-jointed eye” on blueprints
9 Holoprojector grasp/nozzle
10 Upper dome ring (part of dome) / blue neck ring
11 Lower ring (rotates atop body in ANH) / silver neck ring
12 Large data port / hard data input
13 Upper utility arm / upper manipulator arm / upper arm, some droids with rotating “claws” on the end
14 Lower utility arm / lower manipulator arm / lower arm, some droids with rotating “claws” on the end
15 Shoulder hydraulic / long shoulder detail
16 (inside) Shoulder hub / horseshoe interior
17 Horseshoe / shoulder horseshoe / shoulder plate
18 Shoulder buttons / lubrication fittings
19 Leg strut / leg cylinder / leg rod / booster rod
20 Booster cover / booster housing / leg housing
21 Under-shoulder detail / leg stabilizer / "toggle joint" on blueprints
22 Ankle, topped by ankle bracelet
23 Battery box cover (ANH only)
24 Ankle detail
25 Ankle cylinder, attached to ankle cylinder wedge
26 Half-moon detail, mounted atop the trapezoidal foot side plate
27 Outer foot / main footshell
28 Battery box harness (most R2s have two per battery box)
29 Battery hoses with knurled hose fittings
30 Battery box / fuel cell
31 Bracing bar / battery box bar (ANH only)
32 Shoulder pivot / shoulder flange / leg to body hub
33 Right vent / side vent
34 Right tall compartment (interior: right bread pan)
35 Right pocket vent / front external grille
36 Charging bay panel / charging door / zapper panel
37 Coin slots (six)
38 Front coin return
39 Skirt / bottom ring assembly
40 Middle ankle / centre ankle
41 Foot strip / middle toe
42 Middle foot / centre foot
43 Top and bottom front vents / louvered intakes
44 Front power connector / front power coupling / front recharge coupling
45 Large front panel / data port panel
46 Front octagon port / front octagonal port / front exhaust (sic) port / "Unit 'A'" on blueprints
It was difficult finding a photo of the back of R2-D2 from the ANH era. This is the best shot I could find - a promo picture taken during the filming of the Star Wars Holiday Special in 1978. It's the same RC R2 as above, a year later.
1 Top holoprojector / "ball-jointed eye" on blueprints
2 Round pie plate / dome topper
3 (not visible in this shot) Magic panel / picture panel
4 Dome bumps (note: that these are actually flat recesses on this particular dome. Most droids have slightly convex bumps)
5 Rear process status indicator (PSI)
6 Rear holoprojector / "ball-jointed eye" on blueprints
7 Rear logic display / "flashing optics panel" on blueprints
8 Removable rear panel / removable back (ANH only)
9 Rear compartment panels
10 Battery box cover (ANH only)
11 Left rear coin return
12 Rear power connector / rear power coupling
13 Right rear coin return
14 Battery hanger / battery spacer (ANH only)
15 (not visible in this shot: behind ankle) Rear octagon port / rear octagonal port / rear exhaust port
16 Shoulder hub
17 Actor with embarrassing haircut
On to part V: The R2-D2 Detail Catalogue