B9 Robot Radar Section

B9 robot radar section construction reference. See the full B9 robot construction overview.

Frequently Asked Questions

What is the B9 robot radar section? The radar section is the rotating sensor assembly at the very top of the B9 robot, above the bubble dome. It features a central hub with extending arms and illuminated sensor elements at the arm tips, and rotated continuously in the original Lost in Space series via practical mechanical drive from inside the costume.

How is the radar section rotation motorized in a replica? A small 12V DC gear motor at 5–15 RPM output provides one revolution every 4–8 seconds. The motor typically mounts inside the head assembly below the dome with the drive shaft passing up through the dome to the radar hub. A slip ring electrical connector at the rotation axis allows LED wiring to the rotating arm-tip lights without tangling.

What construction approach is used for the radar section hub and arms? Machined aluminum (hub turned on lathe, arms milled from flat stock) is the most accurate approach. Cast rigid urethane resin from a mold is accessible without machining and reproduces surface detail well. Arms fabricated from commercial aluminum flat bar or rod with a purchased tube fitting hub is achievable with basic hand tools. The B9 Builders Club periodically offers community-produced machined components.

What season’s radar section configuration do most replica builders target? Most replica builders target the Season 2–3 configuration of the radar section, which is more thoroughly documented in B9 Builders Club community reference threads. The Season 1 radar section had a different arm arrangement, and the proportions relative to the dome diameter are described as critical — a radar section that is too large or too small reads immediately as wrong.