Jamming Gripper That’s Super Easy To Build

This is the simplest version of a jamming gripper that we’ve seen yet. The only component that might not be readily available is the pump in the upper left, but the rest is all hardware or grocery store stuff. It’s based on the concept we saw from a research video where the air in a bladder full of coffee grounds is removed to grip an item. In this case the bladder is a party balloon which is held in place by parts from a cheap shower head. A theaded-to-barbed right angle connector makes it easy to connect the vinyl tubing up to the pump.

The video after the break shows that this works quite well for small items. But we see a lot of downward force is exerted to firmly embed them in the grounds. We’re not sure if this is par for the course, or if it would work a bit better if more air were in the bladder initially. This other jamming gripper build uses a servo to release pressure from the system, and we think that might be of help here too.

[Thanks Michael]

15 thoughts on “Jamming Gripper That’s Super Easy To Build

    1. Volkswagens and Audis from the 80s to early 90s used a pneumatic pump to actuate the door locks. The pump is a reversible suck/blow one just like this. A scrap car will also yield the special relay to reverse the current though the motor.

  1. I think the best way to undo pressure at high speeds would be to reverse the pump for a short interval. It’s fast and doesn’t require any more parts, but it does require the ability to swap leads or feed in reverse voltages.

  2. Can this tool be used to lift larger flat things, like a sheet of paper or a compact disc i.e. does it have suction or does it have to wrap around the edges of an object?

    1. It needs to wrap around edges, so far as I can tell from all earlier demos. But, the edges don’t seem to need to be very large or very rough. You might be able to lift a large flat object by pressing onto one edge, if it’s thick enough and light enough (I.e., if the angular force with regard to the contact point is less than the weight it can lift in normal circumstances).

      A compact disk is probably liftable by aiming at the middle hole. After all, weaker prototypes can lift full soda cans by the rim. As for the paper, I don’t think so, but it’s easy enough to try: get a balloon, some coffee grounds, a filter, and a straw and see if you can lift paper by the side.

      A normal pick and place is easier to use if you want suction, and would require much less coffee.

  3. Unfortunately, the reversible pumps I found are very expensive.

    You can use two pumps in tandem. If you plug one of them in reverse it can inflate the balloon slightly and make it mushier for better gripping.

    BTW, thanks for featuring my post!

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