pic: Team 399's arm after the SD finals match 1.

[John G]

loading photo ...

[rsisk]

Any thoughts on what caused the failure?

I watched the claw appear to twist while you guys were near the Blue Alliance pegs attempting to hang. I thought it looked odd, guess it was really the arm that was twisting. Then it was, OMG their arm came off!

Sorry that had to happen.

As soon as I saw your alliance with 1504, I leaned over to my neighbor and said "It will be them and #1 alliance in the finals". I knew your alliance was going to be strong, too bad it had to end like it did.

Good luck in the rest of your competitions!

[artdutra04]

Looks stressful.

[MrForbes]

Wow, that's a bummer. It's also a tough way to learn about why tubes should be left tubular, and not cut away....

[Hawiian Cadder]

when i first saw this i thought it was wood. bummer but for replacement thinner walls usually make for a tougher/weight ratio than thick walls pocketed.

[Akash Rastogi]

Is that break also further up the arm? (closer to the pivot)


If you want to pocket, use a smaller diameter and also just use regular holes instead of large slots like this one.

[thefro526]

Originally Posted by Akash Rastogi

Is that break also further up the arm? (closer to the pivot)

From what I saw in the video of Final 1, it looks like the arm broke close to the pivot point, probably within 3" or so. (But I could be wrong.)

[rsisk]

That's what it looked like from the stands, the break was just beyond the pivot point.

[jsasaki]

Thanks for a great alliance guys. Nice being with 399 and 1540 as well as 294 Good luck at your next regional

[robodude03]

The break was about 4" down from the pivot point. The initial end effector (pincher claw) was much lighter before weighing approximately 2lbs. Put a 6lbs roller claw out there (including the pocketing) and you can easily tell why this arm broke off. The stress by the end of the competition was too much.

I can assure you that our new arm will have much less holes by the time we go to LA. It's a painful lesson to learn, particularly in the finals, but one that we will remember.

[r2davis2]

That is terrible, I only saw it from the stands, and it looked pretty bad even from up there. Hopefully you guys can get that fixed because that was one great robot.

I do have to thank you very much for allowing us to be substituted into your alliance

[Ether]

Originally Posted by artdutra04

Looks stressful.

and strainful....

[sdcantrell56]

Is it really surprising that the arm failed given the quite drastic lightening pattern used on the arm?

Definitely a bummer but maybe side on the side of slightly overbuilt versus one hit away from total failure. Also maybe look into fiberglass to save weight without having to be cheeseholed