Bob May passed away on January 18, 2009, at the age of 69. For the community of B9 robot builders and Lost in Space fans, his death marked the end of a direct human connection to the original prop — May was the physical presence inside the robot for every one of the 83 episodes the series produced between 1965 and 1968.

A Physical Performer in an Impossible Role

Building and operating the B9 robot was, by any measure, a demanding physical job. The costume was heavy, poorly ventilated, and hot under studio lighting. May worked inside a suit that restricted his vision, limited his movement, and required considerable physical effort to animate the robot’s characteristic gestures and movements.

He did this for three seasons without screen credit. The B9 was listed as a special effect, not as a performance. The voice came from Dick Tufeld in post-production. May’s contribution — the physical presence that made the robot move with personality, that gave it weight and spontaneity — was invisible to the audience in the most literal sense.

Recognition in Later Years

The science fiction convention circuit, which grew significantly through the 1980s and 1990s, gave Bob May a venue where his contribution to Lost in Space was recognized directly. Fans who had grown up watching the show — and who knew, by then, who had been inside the suit — came to meet him.

May was by all accounts a warm and generous presence at these events. He understood what the B9 robot had meant to a generation of science fiction fans, and he engaged with that connection genuinely. The B9 Robot Builders Club, many of whose members had dedicated years to replicating the robot he had operated, held May in particular regard — he represented the physical reality of the prop that they were working to recreate.

The Builder’s Perspective

For those who have spent time building B9 replicas — studying the robot’s proportions, fabricating its components, trying to understand how every detail of the original was constructed — there’s an added dimension to Bob May’s legacy. The robot that builders are replicating was not just a prop. It was a prop operated by a specific person, with a specific physical presence, who made choices moment by moment about how that machine would move.

Those choices — the slightly hesitant head turn, the emphatic arm gesture, the way the robot seemed to react to dialogue with a beat of mechanical consideration — came from May. They weren’t scripted into the robot’s movement. They were performed.

When a finished replica stands in a display room or convention floor, it represents both the work of fabrication and an homage to that original performance. Bob May built nothing and cast nothing. But the robot that replica builders are honoring is the one he made come to life.

The Series and Its Lasting Impact

Lost in Space ran for 83 episodes from September 15, 1965 to March 6, 1968. The CBS series was a product of its time — campy, colorful, and uneven in quality — but it introduced a generation to science fiction and specifically to the idea of a mechanical companion with personality and loyalty.

The B9 robot’s “Danger, Will Robinson!” became one of the most referenced catchphrases in popular culture, a shorthand for alarm that has outlasted the series by decades. That phrase, that image, that character — all of it ran through Bob May’s physical performance.

The B9 builder community’s ongoing work is, in part, a form of remembrance. Each completed robot is an acknowledgment that the original mattered enough to recreate. Bob May would, by all accounts, have found that a reasonable tribute. Fans and historians have documented his legacy extensively on The Replica Prop Forum, where builders continue to share research and finished work in his honor.

For those beginning their own B9 builds, the construction overview is the starting point. For the history of the prop itself, see the B9 robot history article.

Frequently Asked Questions

Who was Bob May and what was his role on Lost in Space? Bob May was the actor who physically performed the B9 robot in all 83 episodes of Lost in Space from 1965 to 1968. He operated the mechanical suit on set, animating the robot’s characteristic gestures and movements, while the voice was provided in post-production by Dick Tufeld.

Why was Bob May not credited for his work as the B9 robot? The B9 was listed as a special effect rather than as a performance, so May received no screen credit for three seasons of physically demanding work inside the costume. The robot’s voice from Dick Tufeld in post-production meant the audience had no way to identify a human performer from the screen.

When did Bob May pass away and how did the builder community honor him? Bob May passed away on January 18, 2009, at the age of 69. The B9 Robot Builders Club, whose members had dedicated years to replicating the robot he operated, held May in particular regard, and the article describes each completed replica as a form of acknowledgment that the original mattered enough to recreate.

How did the science fiction convention circuit affect Bob May’s legacy? The convention circuit gave May a venue where his contribution was recognized directly by fans who had grown up watching the show and knew who had been inside the suit. The article describes him as a warm and generous presence at these events who understood what the B9 robot had meant to a generation of science fiction fans.

How long did Lost in Space run and what cultural legacy did it leave? Lost in Space ran for 83 episodes from September 15, 1965 to March 6, 1968. The article notes that the B9 robot’s ‘Danger, Will Robinson!’ became one of the most referenced catchphrases in popular culture, a shorthand for alarm that has outlasted the series by decades.

What additional dimension does Bob May’s legacy add to B9 replica building? The article argues that the robot being replicated was not just a prop but one operated by a specific person who made moment-by-moment choices — the hesitant head turn, the emphatic arm gesture, the beat of mechanical consideration. Those performance choices came from May, not from scripts, making the replica an homage to both the prop and the performance.