Could you use vacuum to suck a cube at all/ from an opponents loading zone to your community

Just curious

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By the way, I had no idea what the category would be.

You are allowed to enter the opponent’s loading zone, but you are at high risk of penalties should you be contacted by them within it.

Thanks to @MrRiedemanJACC for pointing out G108.

You wouldn’t have to go into the loading zone though, you could just be in your community, and suck the cube to you

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But if any part of your robot extended into their loading zone, the problem for you still exists.

Now, in theory, you could use a vacuum action to draw a cube to you, but that’s not as easy as it sounds. Our intake last year had poly-belt flappers on it that created a vacuum-like suction within a foot or so of the front of the intake. We did actually use that to develop an auto routine that went to the other side of the field and sucked in a cargo by getting it to move (using the suction) before we touched it. Never used it in competition (though we did have it work on the practice field at Worlds) but the theory was sound and we cleared it with the refs. Problem is that in practice cubes aren’t likely to roll as well as cargo and you’d need something that creates a lot of suction to make it work over any kind of distance. Anything less and you’re all too likely to be in the opponent’s loading zone and vulnerable to fouls.

So, not impossible, but highly unlikely to be useful.

Is there a good way to create a lot of suction?

Remember, “Science doesn’t suck”. (Suction doesn’t actually exist.)

Fans simply push air somewhere else creating a region of low pressure and air flows in to replace it. That mean that while you can direct air by giving it momentum in a particular direction (like a leaf blower), you can’t direct suction in a specific direction. The air will flow in from all directions.

I imagine that it would take a VERY powerful fan to create a low pressure area large enough to pull a cube from a meaningful distance, and moving all that air would take a ton of energy.

As another example: you can easily blow out a candle from several feet away, but even a shop vac would have to be pretty close to “suck out” a candle.


First, a review of the physics involved. “Suction” refers to moving air (using e.g. a fan) away from an area to create a low-pressure zone in that area. This can result in two different effects, depending on the geometry of the low-pressure area.

  1. The area is sealed.
    This is what you usualy get with suction cups. Very little air can enter the low-pressure zone, so your pressure drops very far below atmospheric levels. Taking atmospheric pressure as a baseline, this gives you a negative pressure that attaches the suction cup to a surface. This is the sort of suction you see most of the time in the context of FRC–robots attaching to game pieces or structures with a suction cup.

  2. The area is not sealed.
    In this case, air rushes in from outside to fill the low-pressure zone. You don’t get much of a pressure difference, but you do get some high-speed air moving through the area. Unfortunately, this effect is pretty diffuse, meaning that as you move more than a few inches away the effect becomes very weak, unless you use a tube to move the small area of strong effect.

Your intended use looks to be number 2, and it also seems that you can’t use a tube extension either. So no, it isn’t practical to use suction to try and attract cubes from an opponent’s loading station.

That’s not to say that suction mode 2 is entirely useless. In fact, wind tunnels use this sort of suction. However, wind tunnels are really only interested in the fast-moving air inside the tube. On the outside, you still have a very weak suction (but a very powerful blowing).

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Thanks for the information! This was just an idea I had to give my team an advantage. I don’t know how to create this, or even have an idea of the physics involved, so it’s nice that I have an idea of this now, even if it looks like I won’t be able to do this. If there might be a way, I’d love to hear it.

Think about your vacuum at home and how close it has to be to suck up tiny, almost weightless particles of dust. With the heavier game pieces and the larger distances, I have by doubts you could do it with FRC legal parts.

Another way to test out this theory, if you didn’t know the physics, is to set out a large box fan and point it so the air blows away from the game piece. See how close you have to get before the game piece actually moves. Use cardboard to build shrouds and ducts to try to direct or concentrate the suction. See if the physical prototype seems feasible.

I think you should also look at G108.


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