Clever Suction For Robot Arm Automates Face Shield Production

We’re certainly familiar with vacuum grabbers used in manufacturing to pick items up, but this is a bit different. [James Wigglesworth] sent in some renders and demo video (embedded after the break) of the Dexter robot arm and a laser cutter automatically producing face shields.

It’s a nice little bit of automation, where you can see a roll of plastic on the right side of the Glowforge laser cutter feeding into the machine. Once the laser does its thing, the the robot arm reaches in and grabs the newly cut face shield and stacks it in a box neatly for future assembly. There are a lot of interesting parts here, but the fact that the vacuum grabber is doing it’s job without a vacuum air supply is the one we have our eye on.

The vacuum comes from a corrugated sleeve that makes up the suction cup on the end of the robot arm. A rubber band holds a hinged piece over a valve on that sleeve that can be opened or closed by a servo motor. When the cuff is compressed against the face shield, the servo closes the valve, using the tape as a gasket, and the corrugated nature of the cuff creates a vacuum due to the weight of the item it is lifting. This means you don’t need a vacuum source plumbed into the robot, just a wire to power the servo.

The robot arm is of course the design that won the 2018 Hackaday Prize. I comes as no surprise to see the Haddington Dynamics crew setting up a manufacturing line like this one. As we discovered a few weeks ago, 3D printers, laser cutters, and robot arms are part of their microfactory setup and well suited to making PPE to help reduce the shortage during the COVID-19 outbreak.

9 thoughts on “Clever Suction For Robot Arm Automates Face Shield Production

  1. With how the suction cup works I’d have thought a bi-stable Solenoid mechanism is a better solution than a servo for it. But still neat project on many fronts. Its nice to see smaller robot arms do some useful work and nice to see vacuum handing done without a pump, not always practical but when it is so much more elegant than a pumped system.

    That is a very neat sized laser, I kind of want one now -Might actually be able to fit that one somewhere. Just hope they are doing proper laser safety running it with the lid up.

    1. Better and more capable…but also probably a lot more expensive. With the servo you could potentially modulate the suction slightly so it stays sucked longer…. lower initial sucktio but increase the servo position slightly over time as the suction leaks down.

    1. That has a different limit on how much it can hold – you are applying electric force to keep the vacuum so the coil can only run so long without frying and has to be able to lift the weight in the first place. With this sort of mechanism its passive so can lift as much as the vacuum it can pull – which is based on how far it stretches under the load and its volume (so you can design to your target loads) and with a good seal it can hold for ages.

      Both can be the right solution.

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