AstroDroid '76 Alloy Head Bearing

Original  Design

The original design of the Alloy Head Bearing system was defined on the 1976 Elstree Studios blueprint for the leg drop mechanism. The blueprint defines the Alloy Head Race and Bearing and Bracket cross sections used on the production props.

This cross section is more refined than the cross section shown on the blueprints provided by 20th Century Fox. This blueprint defines the Alloy Head Race as a functional bearing system to rotate Artoo's head while mounted on his body.



These pre-production photos at Peteric Engineering show the Alloy Head Race design realized both the Hero unit (prior to weight relief holes being added) and the RC leg drop unit.

The most significant change from the blueprints in the use of machinists locator pins instead of the stud and washer design to create the 1/8" groove between the Alloy Head Race and the Dome.

 (image copyright LucasFilm referenced under fair use)

 (image copyright LucasFilm referenced under fair use)


This photo shows the Alloy Head Race design made it, as drawn on the blueprint, with the locator pin modification, to the RC leg drop unit.

 (image copyright Chris Casady referenced under fair use)

This photo shows the Alloy Head Race design, made it as designed on the blueprint,  with locator pin modification and additional weight relief holes, to the hero unit.

  (image copyright LucasFilm referenced under fair use)

OpenR2 3D Geometric Specification

The OpenR2 AstroDroid '76 specification for the Alloy Head Race was modeled in CATIA V6 running within the Dassault Systems 3DExperience Platform running in the cloud.

The original Elstree blueprints we scanned full sized at 600 DPI using a high-performance large format Scanner called CRUSE used by the design industry, museums, libraries and archives

Both versions of the the head race and both versions of the dome gap separation are modeled as variations. This means that all three assembly variants  are captured.

Variant A (as drawn on blueprint)


Variant B (with locator pins)


Variant C (with weight relief holes)


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