Thoughts on "simple" multi-stage climbs?

Easiest example is a cheap (or expensive I suppose) carabiner. Not sure I would actually mount a carabiner to the robot, but I think you could easily go off that concept.

McMaster has a nice selection of torsion springs that I think would serve nicely as the spring pivot of the carabiner. With those, some bushings, bolts, and aluminum, I bet something could be mocked up for a spring, latch system.

One example from 2013 off our robot that we used to use a spring-loaded hook to get past each bar. Not the best pictures, but between the two you can kind of tell what’s going on. Top set of hooks would pull the bar you are lifting up to past the lower hooks to engage on the bar.


image

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Seems doable to duplicate this from underneath. Heck, just copy what they did in the game reveal vid and put a bumper around it.

An idea, The Rotoclimb: https://i.imgur.com/dUXrSMn.mp4

Currently designed with the pneumatic claws in mind. Main rotation is motor and sprocket powered. Really want it to be completely passive with spring activated and locking hooks. Currently can use limit switch feelers to trigger pistons when bars are aligned so the driver doesn’t have to do anything. Also needs the tower to be shortened a bit so as not to fall outside the max height at start, but I didn’t want to bother to re-animate the whole thing and you get the idea.

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Awesome animation, very easy to visualize. I really hope we see something like this on the field! Hope someone takes this and applies some physics to it.

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Neat idea!
R204 called - do you plan to bring a ladder on the field so you can take it down?

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@GeeTwo I imagine that you get two people to hold the robot from the bottom at either side and then a third person hits the mechanical solenoid trigger button or dumps the air to release the pneumatic clamp

@wolly_efendi Thanks :). What kind of physics analysis would you be interested in? The animation I drew is quasistatic so it includes center of mass calculations but not dynamic robot swinging which could be a problem (and why I want the claw actuation trigger to be automatic)

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Check out 2994 from 2013 for a very similar concept. FIRST Robotics 2013: Astechz Team 2994 - Design 1st | Product Design Company

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Sweet!! That’s exactly it, even down to the hook geometry!

It feels like there has to be a way to make what was shown in that video faster. I wonder what the delay was in each swing up step.

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Very interested to seeif they will have a high or traversal climber as we compete with them this year.

Something with the dynamic robot swinging would be nice. It’d also help get a better idea of the forces going on - I don’t really have a reference for how torquey the gearbox would have to be, or how hard you’d need to clamp onto the rungs. With a clamp too strong, wouldn’t it be tough to rotate around the rung? I feel like the robot swinging is going to have a big effect on the design and the teams that can control that will have the fastest climbs.

Just a question about geometry, if the green tower is lowered, will the black arms be long enough to reach the next rung? Or would they need to telescope as well?

Also, could you please share what you used to make that animation :slight_smile:

The “simple” multi stage climb approach was already solved in 2013, the challenge is to adjust it to the new field geometry.

Here is a scale model to fit the new field: LINK

I think that 1986 boiled this down to the basic concept the best in 2013, If I was writing an internet article I’d cite them as the source.

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Yeah we were looking at 1986’s design from 2013 earlier as well. I think theirs was a little different, in that they rotated their fixed hooks (which rotated the robot) rather than rotating the elevator/telescoping mechanism but that idea seems to me to be the easiest one to implement.

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if the hooks are actuated by pistons just put a release valve some where along the arm and just open it at the end of the game to take it off the bar. Be cool to see this idea made.

It essentially has to raise a robot on a moment arm a bit over a foot long as the arm passes through horizontal. Assuming a full weight robot, batteries and bumpers, and a 50% safety factor, something on the order of 275 ft-lb. Looking at ~340:1 reduction for a single Falcon 500 with a 60A current budget.

As to what that would look like: #35 chain has a 560lb working load, so you’d want a final sprocket at least 12" in diameter - nothing like that COTS in the FRC ecosystem as far as I’m aware. OK, scratch #35 - this sounds like a job for a bicycle crank - it already has the arms attached. Then you just have to get the small bicycle sprocket adapted to FRC hardware.

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Thank you for the great visual of the idea I was having.

This is incredible!

Brb posting in our team Slack :eyes:

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Literally sketched this concept up in SolidWorks (2d side view sketch) this morning at work. Now I’ve got a video of the concept moving to show the team too! Thanks!

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I imagine that the fully clamped position for the clamps is a bit larger than the bars so you don’t actually exert any torque on them. Maybe clamping harder on them would help with the swinging issue though, as it provides a place to dump that energy.

You can keep lowering the tower until the arm just reaches the medium bar when it’s vertical. That’s a long way away. The arm will not need to telescope. The space between bars needs to be the same as the black arm. It doesn’t depend on the green tower height.

I drew the robot in SVG in inkscape and then animated it in enve . I hadn’t used enve before, but it was pretty simple to use and worked directly with SVGs. I did find some bugs and crashes though. It looks to be in active development.

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