The Sad Story of Walter, the Retired Industrial Arm

3D Printing & Imaging Digital Fabrication Robotics Technology
The Sad Story of Walter, the Retired Industrial Arm

As seen in the video below, “71% of elder industrial robots feel like their work is becoming meaningless.” It probably doesn’t help that manufacturing engineers don’t really enjoy having to boot up an 80s-era computer and find a long-obsolete cable to talk to them. However, taking Walter’s sad tale into consideration, perhaps we should be a little nicer to them.

Walter, an older 6-axis robot who bears the distinctive 50s style of the former German Democratic Republic (or DDR, and no, not the dance game), has been living in a house with two ladies that generally ignore him. In fact, they seem more interested in comic books, selfies, and playing the occasional “puppet over the gripper” trick on him than help with the solitary Tower of Hanoi puzzle he’s been given to entertain himself in his latter years.

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Okay, perhaps it’s not as sad as the first part of the video would make it out to be. Walter is in fact quite happy and is a creation of German software architect Jochen Alt. He “wanted to build a robot that looks like [him] – vintage.” His daughters Evi and Katrin star in the video, and, unlike their on-screen personalities, they are actually quite nice to robots in real life.

Alt built this amazing ‘bot using servos with belt drives to move 5 out of the 6 of its axes, with the 6th wrist axis being turned by a servo. The gripper is actuated by a servo as well. The body was 3D printed and the surface was prepared with primer and filler. The ‘bot was then painted in a Reseda green that was a standard for machinery in times past—a color many engineers will recognize from the older equipment in their factories.

Walter under construction

The beauty of this device isn’t just skin-deep however. It extends to the mechanical design as well as the excellent documentation. It uses 80 bearings in the arm, including one with a diameter of 110mm in the base. Alt has also mostly eliminated motor bulges in the structure. It is quite impressive when compared to the use of duct tape, glue, and assortment of whatever is handy that is normally used in the bearing surface of many people’s builds.

Alt notes that most robot makers stop with their builds as soon as their creation is able to move. Making it move well is part of the process though, and he went through some rather involved Bézier curve equations in order to control the arm’s trajectory. As it would be ridiculous to do these calculations for every movement, he then undertook the “trivial” task of actually setting up PC software for trajectory planning as well as hardware in the arm’s control cabinet. Data is displayed in OpenGL on the PC and then transmitted to the cabinet for execution.

It took Alt around 30 weeks to build Walter. He worked at night on the weekends and two “vacations on the beach when [he] had a lot of of time to work on the CAD design.” The video didn’t take that long to film, but Alt says that it took him a week to convince his daughters to play such a mean role. He says, “They really love Walter and it is just a role and they would never be so mean to any robot and they have been bribed by their dad to do such things.”

It’s really an amazing robot, and one that wouldn’t look out of place on a factory floor somewhere. However, Alt says that like many maker projects, Walter “is shelfware now.” It seems that even though there is always a goal to strive for, the fun is in the creation and not necessarily the finished product!

So if you want to build the best 6-axis retro-style robot in the world, don’t bother. Jochen Alt has already built it. Okay, that is not really in the maker spirit. Let’s just say that Alt has moved the bar higher, and we cannot wait to see what amazing projects that Walter inspires!

If you do want to build your own Walter, or perhaps your own spin on it, Alt has provided excellent documentation of the project. CAD files, code, data sheets, and everything you could want to know can be found on his GitHub page. Summaries can also be found on and

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Jeremy is an engineer with 10 years experience at his full-time profession, and has a BSME from Clemson University. Outside of work he’s an avid maker and experimenter, building anything that comes into his mind!

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