A Slightly Massive Oversight... Any Help?

Hello! This is my first time posting here, I just need some second opinions.

I’m a captain of a second year team and we may have made a bit of a blunder.
Our design this year implements an accumulator that begins within frame perimeter and folds out to 8 inches, however in the process, we reach a maximum extension of ~15.75. Big oops. This is simply to accumulate power cells, not to score or hang, so would this qualify as a violation of rule G18?

I believe that does violate G18 if at any point your extension goes past 12in


You can’t extend more than 12 inches outside the frame perimeter for any reason. It doesn’t matter if scoring is involved - that would only escalate the violation to egregious.


I understand… thank you so much for the speedy reply!

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No problem. I hope you can resolve your extension issue!

We’re thinking of offsetting our system the necessary ~4 inches and positioning it with a pneumatic cylinder. Should work. Fingers crossed :crossed_fingers:.


How do you even have a mechanism that requires extending almost twice as far outside your frame perimeter as its eventual configuration? It seems like you should be able to find a simpler method of articulation, as you mentioned you’re trying to do.


It’s honestly pretty simple, it just hinges from the top. I’m not particularly good at explaining… you’d have to see for yourself, but it’s all rather confidential at the moment. We just weren’t considering it’s full path. As I said before: a massive oversight…


Just redesign…and be happy stay within 12" and inside frame perimeter at start

One small addition, you can have a mechanism that could if allowed free travel extend past 12" if you can show that you are constraining it either mechanically or with software to stay within 12" of the FRAME PERIMETER. I don’t think this will help in your cause though.


My understanding of OP is that it swings out wide before assuming a mostly vertical offset at the end of its swing. This would be very easy to do for either a Control Panel manipulator or a high shooter which can collapse to fit under the trench run, and likely some other useful-if-not-illegal cases.

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I believe the posts here are accurate. Best of luck resolving the issue! Great job catching it at this stage!

A word of encouragement: 14 year old teams also get frame perimeter rules wrong sometimes.. The fact you found it now is a very good thing!

Feel free to post back here if you run out of mechanical ideas. Folks on the internet like to give options and opinions.


Don’t feel bad we scrapped our intake too yesterday, same reason. It happens after teams watch Ri3d and try to copy. Now we are working on a real lighter thinner intake.

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https://www.youtube.com/watch?v=EqFInNY2Blk we did the same thing in 2016 watch in 2:25 or there is also this example on the competition https://www.youtube.com/watch?v=hVFvCy02-vo&list=PLLDODAGuIHqNRyZPxoHlvwMsJYP79ptCv&index=34

I thought I’d just mention this. It sounds like you are swinging in a big circle to avoid your bumper. However, bumpers are intentionally compressible. Maybe you can get some of your space back by intentionally compressing the bumper (temporarily) as the device passes.

I suspect OP has a mechanism that deploys like this:

I’m sure they can figure out another way of achieving similar motion without violating the 12in extension rule. A 4-bar (or virtual 4-bar) would be one easy way to solve this problem.


You’re correct with that original drawing. The structure itself is more like the vertical and horizontal components of that line segment. I’ll check into your recommendation of a four bar, though it might be difficult to implement the same system… thank you!

Here is some media of our 2015 virtual 4-bar. Using sprockets/chain/wire rope makes a compact and robust 4-bar motion.

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