Out-of-position welding occurs when you have a seam between two pieces of metal and the seam is not horizontal. Companies would spend a lot of money to build fi

Out-of-position welding occurs when you have a seam between two pieces of metal and the seam is not horizontal. Companies would spend a lot of money to build fixtures to rotate their equipment in mid-air so seams could be flat and they did not require Master Welders but could use lesser-priced regular welders. Some industries, such as making super-tankers, cannot do this and have to employ Master Welders. I was hired because I did machine vision in grad school (using punched card images because the the school did not own a camera). My job was to use the camera to optimize the 'puddle' of molten steel as it melted so the seam was precise. But some bright spot figured out that we could use current-feedback from the arc instead (so we never bought a camera). We created a robot that you could just guide along a seam to be welded, press a button, and it would weld the seam. It was light-weight and could be clamped anywhere so it was extremely portable and perfect for things like ship-building. Everything ran off my PDP-11/40 computer which we loaded using paper tape off a teletype machine. We shipped the robot, computer, and teletype to Detroit for the demo. Just for precaution because something might go wrong I used mylar tape instead of paper tape. We get to Detroit the night before. The investors would be in a big hall next to the demo room where we had the equipment. Joe Engelberger (https://www.robotics.org/joseph-engelberger/about.cfm https://www.robotics.org/joseph-engelberger/about.cfm) was to give them a big speech and then bring them in for a demo. The truck arrived that night. We started unpacking. The robot was fine. The PDP-11/40 had all of its circuit boards in a heap at the bottom of the box. The teletype had a big V dent in the keyboard (up to the Y-row of keys) because the fork-lift smashed it. So we reset the PDP-11 boards and rewired the teletype so we could start/stop the paper tape reader and give commands by switch without using the keyboard. Then we tried to load the program but it wouldn't work. It turned out that the memory-address chip on the PDP-11 memory board was cracked. So we ran out to Radio Shack as soon as it opened in the morning, bought a replacement chip, a soldering/desoldering gun, and some solder. We replaced the chip while someone stood at the back of the lecture hall signalling Joe to "keep talking". Finally we loaded the paper tape and it worked. Oh, the joys of programming.