Three Finger Gripper


My first post on this forum. Just learned of it’s existence… And I am so happy it exists!!!

Brand New Coach of a second year team. We are looking at a Three Finger grabber/gripper for the 2019 competition.

Looking to find something COTS that would work to grab the 19 inch ball. Or how to make a gripper/grabber.

Looked all over YouTube and Google, not having any luck. Maybe I’m not using the right terms?

Any help is appreciated. I can use all the help I can get. Thanks in advance.




The ball (CARGO) is only 13". The HATCH PANEL is 19". Assuming you meant the hatch panel and not the cargo, you likely don’t want to grip the panel at three points because you’re more likely to have one point be in the area where the field loop tape is. The top and bottom of the hatch opening has a cut-out to allow for robot manipulators to easily place the panel.

If you are trying to grip the ball, a lot of folks are having good luck with a roller system rather than a grabber. (A grabber is much harder to line up and is slower.) Something like this is likely to have good success this year (though I’ve seen other designs that look like they work as well):



To add on a little bit: I can honestly say that I haven’t seen a pure claw gripper for a ball since 2004’s large exercise balls. Or before. (With a couple of notable exceptions, but one is a suction cup and the other I’m not 100% sure what it was.)

I have seen roller claw grippers ('08, '14), but the vast majority of grippers/intakes for balls are roller or belt only.

I suggest looking through 2016, 2008, and if there are any 2004 match videos on there I’d look at those too.

If you’re referring to the hatch panel… I feel your pain.



I would consider a two claw grabber as a possibility for both the CARGO 13" (out in) and the HATCH COVER 6" center (in out). A pneumatic grabber would be good for HATCH COVER retrieval and centering and could be used for CARGO retrieval too.

The traditional way to get balls is over the top rollers as that provides speed, however with only one item at a time and accuracy being paramount a grabber could do the job well. Might be complex to work in all situations.



you didn’t see this robot? I’m surprised.

also, the gripper that it was developed from, was Team 39 in 2008.

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Look for 3d-printed gripper.
You’ll find a number that use fingers like the one below.