What’s the name of this arm lift and is there a cad file for it or something like it?

Technical 3D Animation and Competition
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What’s the name of this arm lift and is there a cad file for it or something like it? https://youtu.be/lexMGauSCZ4

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The dimensions of the 2013 and 2021 climbs are quite different. You’d probably need a different arm length, and certainly a different hook geometry so you don’t fall when disengaging the passive hook from each rung. But it does look simple - control the angle of the lower arm with respect to the robot, spring the upper arm to lower arm angle open, and control the length of the third side with a winch.

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Go look at spectrum’s build blog for this season. They are doing a similar climb

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Thanks, we will look into their build log.

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Mr Gus, first thank you for your reply, I created a prototype of how I thought it work with dimensions for this years game. We ran a rope from the top of the top bar through the bars to a tensioned spring on the bottom bar and a pulley connected to the top of the top bar to a motor. This didn’t work, we think it’s a problem with the spring placement, do you know the problem with it?

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It would be very helpful if you posted a photo or a video showing your mechanism

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You will need two motors. One for the winch, and another to drive the lower arm*. If you don’t control the lower arm, you’re just going to get the moving hook going back and forth on essentially the same trajectory relative to the robot; this climb requires two degrees of freedom in the moving hook location both to engage the moving hook on a rung and to engage/disengage the fixed hook from a rung.

After working out a somewhat similar solution, I suspect that the geometry will work out better if the passive hook is a bit further off center (front to back) than 1763’s in the video. But maybe not if you’re going up one rung at a time. In 2013, rung-by-rung climbs were mandated by the rules. In 2022, you can skip a rung if you can make the geometry work.

Also, if you aren’t getting enough lift from the spring between the two arms, put a spool around that shaft under the rope to increase the torque.

* the motor controlling the lower arm does not need to be as beefy as the one on the winch. I would recommend putting a backdriveable gear motor on it, with the controller in coast mode and put it in coast when pulling the robot up on the moving hook, and only operating it when the moving hook is disengaged. You will want controls on that motor so it acts like a servo - that is, the driver is controlling its angle rather than its speed.

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Thank you for the reply, we really appreciate your assistance.

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