FRC 2363 Triple Helix 2019 gripper prototypes

Triple Helix has progressed through several prototype hatch grippers. See where we’re heading this year…


Looks good, we had a similar thought to the integration of the hatch and cargo intake like that at the beginning. We still integrated it but went a different route. Glad to see someone went with it. GL this year.

Thanks Triple Helix!

Always cool to see these videos. Years of watching your super high fidelity prototypes played a part in how our internal prototyping process has evolved. This Hatch Gripper reminds me a lot of the 2015 Can Gripper video.

That is awesome.

My team was also thinking around these lines… but…(there is alway a but)

How about picking up off the floor? Or are we wasting our time in your opinion of trying to make something that gets the Hatch Panels from the loading station and from dropped to the floor?

Best wishes in the coming competition.
Russ R.

That arm looks just as awesome as the gripper. I’m excited to see this thing in person at Haymarket.

What made you go with wheels on the sides for that prototype? Does it acquire the ball well still without requiring a good degree of precision from the driver? We discussed a design like that earlier in the year but have tabled it for the time being because we thought we were more liable to push the ball away from us while trying to acquire it if the intake wasn’t almost dead on.

Prototyping it would have been best, but we’re a fairly low resource team. ;(

Definitely not a waste of time picking up from the floor. But, floor pickup is lower down our prioritized list of robot functions. We’re considering something that will flip up a hatch to a position where our gripper can grab it.


[quote=“DRandhawa, post:6, topic:342403”]
What made you go with wheels on the sides for that prototype? [/quote]

Early expetiments with last year’s cube intake, and watching other prototyping vids on youtube. We wanted something that would both intake and spit out cargo. Wheels are an easy way to do that.

That remains to be seen, but we prototyped several simple cargo gathering mechanisms that put the ball in a happy place for the gripper to grab it.

Are those plastic pieces spring loaded to return when the pneumatic disk isn’t pushing up on them to make them spread open? I can’t tell for sure but those look like a spring hinge I may have seen before at a hardware store.

Have you guys played with the quantity of “flaps” at all? We also started with 4 flaps at 90deg intervals, but are planning on trying 2 flaps to see if the grip is sufficient, while enabling more possibility for rotational misalignment of the hatch when scoring.

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The fingers are spring loaded with torsion springs. The components are COTS, but it’s not an off the shelf hinge.

What’s the wingspan on this thing?

Well, as you can see in the video, there were 6 fingers on the 2015 bot, necessary in case some fingers happened to line up with the slot in the lid of the can. The latest prototype has 4, up from 3 in some of our early CAD models. Trying 2 sounds like a fun experiment.

“Wingspan” has to be less than 3.25" because of the depth of the loading station.

edit; might have misinterpreted. I was assuming the “wingspan” of the claw fingers, not the cargo mechanism

In the starting configuration, the cargo gripper arms are just narrower than the frame perimeter. When retracted, for handling hatches, the wingspan is just wider than the frame perimeter.

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That’s a pretty great design! very simple and elegant. It will be a beauty to see in person.
We were looking to do some form of integration between the manipulators, but for now trying to separate them and see how the prototypes turn out.

We were considering something similar, though we’re likely to go with something like the Everybot mechanism for effective simplicity. I was thinking 2 vertical fingers with a bit of looseness in the grasp to allow the hatch to teeter a bit along the vertical axis to make placement easier and not require the robot to be straight on in hatch placement.

We’ve been working along these same lines too, and I have to say that once again your team is absolutely heroic to be testing and posting all this.

Can I ask, what is your source for the torsion springs?

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Congratulations Triple Helix on another early season inspiration generator. One thing I noticed in the video, the smile from the student holding the back of the gripper toward the end. That smile says success, both in the working gripper and the inspiration due your program. Best Regards.


We are currently using 9271K604.

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