B9 robot leg section reference. See the updated B9 leg section build guide.

Frequently Asked Questions

What is the structure of the B9 robot leg section? The B9 leg section consists of two vertical pillar-like tubes connecting the tread base to the torso, approximately 8–9 inches in diameter and 14–16 inches tall. The leg tubes have horizontal ribbed surface detailing of approximately 6–8 ribs of varying widths, with the topmost rib being the widest, running around the tubes as a characteristic visual element.

What structural core runs through the B9 leg section? A rigid structural core of Schedule 40 PVC pipe (for static display builds), aluminum tube or pipe (for frequently transported robots), or square steel tubing (for full walk-in builds) runs through the center of the leg shell. The core connects to tread frame mounting plates below and a torso mounting plate incorporating a turntable bearing above.

How are the B9 leg tubes attached at the bottom and top? At the bottom, the leg cores bolt to mounting plates on the tread frame using heavy flanges with multiple bolts, as this joint carries the full weight of everything above it. At the top, a mounting plate or bracket with a lazy Susan turntable bearing allows the torso to rotate while transmitting its weight down through the leg cores.

What finish color are the B9 robot leg sections? The original B9 leg sections were painted in a silver-grey automotive metallic paint. Modern replica builders achieve this with a base coat of medium grey automotive primer, block sanded smooth, then finished with metallic silver automotive paint. Dry-brushing silver over the grey base coat can bring up surface texture highlights to match reference photography.

Further Reading from Authoritative Sources

  • B9 robot leg section — Wikipedia’s Robot (Lost in Space) article provides authoritative production design details for the original prop’s leg section construction.
  • Lost in Space production — Wikipedia’s Lost in Space article covers the three-season production history and prop modifications that affect which leg section configuration replica builders target.