Cargo dynamics

Wondering about the actual dynamics of cargo. These things have a decent bounce if filtered from the high goal, and point to the sides and terminals. Of course, rolling around as well. Would be interesting to try and do some simulation on this. Thoughts?

I think so long as you don’t have the actual game piece your best hope is to experiment with normal tennis balls

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Link to clip showing how bouncy Cargo is.
Also, section 5.7:

CARGO is inflated to 3½ psi. Typically, if a CARGO is dropped on FIELD carpet from a height of 3 ft., it bounces back to a height between 2 ft. 1 in.

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Beyond the simple bounce, wondering about patterns of roll, etc. (and we have the two pieces, inflated, they certainly bounce!). Ordered 4 more.

Hopefully no DEFLATEGATE issues!!

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one of ours seems to not be a perfect sphere, kinda potato shaped a little bit. so the bounce direction isnt 100% predictable. we also noticed it bounces different if it hits the little air filling port on the bottom

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Anyone have any idea how events will control this? All the inflators I’m used to are in the tire-oriented 20psi-120psi range.

I used my auto tire inflator for the game pieces, and have distinctly different results between the two of them and not enough range on the dial to come close to control…

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I too worry about consistency in inflation pressure. This is a relatively low pressure for a lot of common household type gauges and pumps. Needless to say, instrument error could be a big deal here.

Perhaps it’s much ado about nothing. Some insight into the field procedure and equipment would assuage my concerns.

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A simple basketball pump could work. Something like this one offers a gauge. While it goes up to 20PSI, getting in the 3.5PSI range wouldn’t be too difficult with it.

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Who knows what first will use this year, but judging by years past it’ll be a go-or-no-go system that they judge through size. My team made a small ring with an inner dia. of 9.5 in (the outer dia. of the balls) to judge our cargo. This makes the pressure less regulated and the cargos’ reactions more random, but we also get to plan for this randomness

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I wish FIRST would have thrown the “official” pump into the KoP… At least give us the SKU!

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Looks like the Cargo uses inflation pressure similar to a volleyball.

Thanks, I learned something about sports today.

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No, they will be controlling pressure. For 2019 cargo, the go no-go system was described explicitly in the season rules. This year’s season rules say 3.5 PSI.

@Jon_Stratis thank you for the keyword, I didnt think of approaching it that way :sweat_smile:

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Team 4153 builds robots at 7200 ft (2200 m) above sea level. Real tennis balls are crazy bouncy at our elevation, in fact they sell high altitude tennis balls (or used to). We’re going to have to study how to best simulate sea level bouncy cargo (we’re part of the Texas Districts and never play at our altitude). Guess I’ll assign that task to our tennis playing members :slight_smile: Drives us crazy every time there’s a game piece which is an inflated ball of some sort. (Bumpers squish/shrink some at sea level too, tight bumpers at 7200 feet are pretty sloppy at sea level).

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Oh shoot thank you for the info/correction!

Huh, now there’s an issues that never would have occured to me as being an issue for teams… :exploding_head:

Cargo in 2019 had a similar issue, we competed at Flagstaff which is pretty high elevation, close to 7000.

our school is around 4200 ft, and Phoenix, where we have competed often, is around 1200.

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@gerthworm made a pretty neat simulator tool:

You can run it with Octave: Download

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For those that have recieved their kits/cargo already, can you confirm the cargo inflates with a standard “needle valve”? Like a generic ball pump would work? Sounds like it from above, but want to confirm before I order a pump specifically for inflating cargo.

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Yes, it does.

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