Unimate on the General Motors line

Unimate, the first industrial robot, went to work in the car industry: by the museum's record at the General Motors plant in Trenton, New Jersey, lifting hot castings out of a die-casting machine.

Unimate stored up to 200 positions on a magnetic drum and replayed them point to point. Each axis had a position encoder, a comparator drove the hydraulics until the difference closed, and the robot could wait for an external signal such as a press die opening. So the maker's engineer, at Consolidated Controls Corp., described it in May 1961. Devol's patent was filed on 10 December 1954 and granted on 13 June 1961. The robot cost $25,000, and two Detroit carmakers' spokesmen, by the same journal, winced at the price. The press of the time names neither plant nor date: in August 1962 Popular Science says the first robot had recently begun a similar job for one of the leading auto firms, which kept its trials a trade secret. The plant and the year are the museum's: The Henry Ford, which holds the machine as a gift of Unimation, describes it as the first Unimate ever used on an assembly line, installed at the General Motors plant in Trenton in 1961 to unload a die-casting press; that is a later catalogue description, not a document of 1961. The absence of vision is what separates this line from Shakey eight years later.