B9 Robot Torso Construction

B9 robot torso construction reference. See the updated B9 torso build guide.

Frequently Asked Questions

What are the key features of the B9 robot torso? The B9 torso is the visual centerpiece of the robot, containing the chest light panel (colored LEDs in red, amber, green, and blue), torso rotation mechanism, surface control details sourced from industrial hardware, speaker grille, and the main structural armature. It is approximately 22–24 inches diameter and 18–20 inches tall, varying between Season 1 and Seasons 2–3 configurations.

How is the B9 torso shell fabricated? The three main approaches are fiberglass over a foam or plaster buck (traditional, most common), cast urethane resin from production molds taken from a sculpted buck (more repeatable, produces smoother surfaces), and CNC-machined aluminum panels (highest accuracy, museum-quality builds). The torso shell is typically built in front and back halves that are trimmed and bonded with an internal flange.

What rotation speed is correct for the B9 torso? The original B9 torso rotated at approximately one revolution per 4–6 seconds — slow and deliberate but clearly moving. A 12V DC gear motor at 10–30 RPM achieves this through an L298N H-bridge driver controlled by Arduino. The motor drives a rubber wheel against the inner edge of a lazy Susan turntable bearing mounted between the leg plate and torso floor.

How are the original B9 torso surface details replicated? The surface details (knobs, switches, dial faces, pipe fittings) were sourced from 1960s industrial hardware catalogs — identifying the exact original parts is an ongoing community research project. For replication, details are cast in urethane resin from molds and bonded to the torso shell with two-part epoxy. The B9 Builders Club forums maintain the most comprehensive research on specific commercial parts used.