Team 4907 Presents: Darth Theta

Can you explain a bit more how you pull the vacuum force. What is the mechanism/number of motors/ratio, etc?

This thing is sick.

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amazing !
creative, innovative
great design, engineering, and implementation

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This was the most impressive aspect to me as well. Seen way too many teams try to do something unique for the sake of doing something unique and then compromising on every other subsystem. This is definitely not the case here!

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Honestly I’m the most impressed at this post. A lot of teams would just build it without this in mind but the fact that you guys went above and beyond to make it safe is impressive to me.

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I am truly speechless.

I have so many questions but I don’t even know where to start.
I wish I could see this in person.

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All the physics involved are mostly covered in the Jump Climb thread. The three main equations you need to calculate the dynamics of the jump are W=Fd, F=ma, and Ek=1/2mv^2, and that’s all high school physics, which is really cool.

But the mechanism itself isn’t intuitive. However, the best way we’ve found to describe how it works is to go in your medicine cabinet and pull out a syringe, like the ones that come with kids Advil or Tylenol. Take a piece of duct tape and put it over the tiny hole at the end so it’s sealed. Now try to pull the plunger out. You’ll notice that it takes some force to move it.

This force is the net force of atmospheric air pressure on the outside, and no force (vacuum) on the inside. It’s proportional to local air pressure (about 14.7 PSI) and the cross sectional area of the tube (A = pi x r^2).

Notice that it’s constant force, which means this acts like a constant force spring. By pulling the plunger out, you’re storing energy in the system (W=Fd). Assuming you have a good seal, you can control the force by adjusting tube diameter, and you can control the amount of stored energy by controlling how far you pull up the piston.

So yes, we built a giant syringe.

We dubbed it the Atmosphere Into Robot Rapid Ascent Mechanism. (A.I.R. R.A.M.)

:grin:

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Sorry, I wasn’t clear what I was asking. I understood how the vacuum itself worked to accomplish this.

I guess I meant more what does the mechanism look like that is pulling the syringe as you put it. What is the mechanism that is pulling the syringe, how is it powered, etc.

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Well, making it safe was the starting point. Making it score points is going above and beyond. :grin:

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Game Design Committee:

Team 4907:

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As soon as I saw it work I immediately checked their bumpers, and yeah sure enough.

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Two winches, one per side, each with a Falcon 500, a versa gearbox (can’t remember the ratio off-hand), a ratchet block, and a winding spool. Again, I can’t remember the diameters, etc., sorry!

If there’s enough interest we’ll put out more details once we’re though this season. Right now it’s a bit hectic. :slight_smile:

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Trust me, there’s enough interest :rofl:

@Tyler_Olds I’d say this is an excuse enough to make your way up to Canada. We need a behind the bumpers of this machine ASAP!!!

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https://www.youtube.com/watch?v=SwYN7mTi6HM

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This robot wins every creativity award this season full stop. I’ve seen some innovative robots before but this thing takes the cake… Not just the fact you did it but that you also made it safe and legal. Kudos to your team for pulling off this unicorn of a robot! Cant wait to see this bot in competition!!

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Thank you everyone for all the support. The Jump Climb thread caused us a lot of anxiety all season long. The team is relieved by all the positivity.

What an amazing community!

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As one of the skeptics in the other thread, I have to say that I am in awe of this achievement. I love everything about this robot.

I also love the understated reveal. “pew pew pew pew pew pew pew pew pew pew pew pew sproing click gasp… applause!”

How much vertical do you get out of that jump? In the video it looks like you’re able to lift the bottom of your bumper by 20 - 30 inches? Astonishing…

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That jump climb is really amazing, kudos to your team for making this work!

I am really hoping the inspectors don’t give you a hard time for your vacuum mechanism! 4 seasons ago, my team built a mechanism designed to pull a partial vacuum as part of a “soft robotics” mechanism design (the vacuum was built to change the shape of our mechanism to aid in intake). Unfortunately because the mechanism moved air and had a pressure differential from ambient, the inspectors deemed it to be a “custom pneumatics” and disallowed it per this year’s equivalent of R802

Was there an equivalent rule to the R804 Item M blue box “a” that year?

image

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I’m just going to pop this right in here:

FRC_4907__2022_Robot_Reveal_Darth_Theta

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This is such a clever, thought-through design. Well done.

Do you have any features to locate the bumper frame within the “wheels frame” when it’s retracted, or do all of the bumper loads have to pass through the linear guides?

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