5090X End-Of-Season Explanation

Here is my team’s states robot. I filmed this in mid-march and disassembled the bot shortly afterward. Feel free to ask any questions you might have, and I’ll do my best to answer them.


what does the c channel coupler on your drive achieve?
You said in the video that it’s a must-have and there’s no way around it but I’ve never ever seen that before.

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I dunno what you mean. It’s there, and it accomplishes nothing. Having a single coupler on your chassis is vital to a good robot. There’s no way around that.

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Pretty decent bot well done, the cube lock is a nice touch. The reason your lift motor burned out so much is because your arms are too long, even a 1:7 ratio and torque cartridge cant handle that. Just a useful tip, pretty nice bot overall though.


I like the intake locks. About the 4 bar stalling, it’s probably a combination of the geometry (the current way you have it moves the actual arm faster then the bar powering it) and the screw joints on the 4 bar. It doesn’t look like you used any nuts to secure the screw on the 4 bar screw joints which means that the screw will rub against the metal. To fix that you could just do something like this:

screw joint

so the screw only turns inside the bearing and will turn with the metal bar its tightened to.

Other than that looks pretty nice.


What do you mean about the arm moving faster than the 4 bar?

I’m not sure what you mean by that? Can you share the timestamp you’re referring to?

Sorry; that was in reference to @Zach_929U’s statement right above my post. I was just curious how that worked.

Just so it’s clear, @Zach_929U, The motor powers the arms. The mini-4-bar is solely for rubber banding purposes.

That’s what it looked like. That’s why I was wondering about how there was a geometry difference.

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The geometry of your 4 bar is not a parallelogram as seen below.


Your 4 bar looked like this.

The top part of the bar being much closer than the bottom part of the bar, this would cause your torque exerted on the top bar to be much weaker than it could be.
Also being able to adjust your compression probably created more friction by pulling your gears closer together causing them to create more friction. Also unlike what @nware49 said, your arm length isn’t too long, I ran a full length boxed lift and ran it 1:5 on 200 rpm cart for a 40 rpm life. and the motor never got warm.

I don’t see how that matters. It’s not powered, only rubber-banded.

This was an issue well before I added that standoff.

oh, I just assumed the 4bar was to power the lift as you can rubberband without a 4bar.

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Most people use the 4-bar as it allows for easier rubber banding. In my case, it actually haloed a bit with intake compression.

Great video! I like how the tray is attached to the robot by hinges.


The partial 4 bar is introducing a lot of friction because of how the screw joints are done. That in combination with the length of the arms (and all the extra weight at the end of it from how the intakes were done), as well as the fact that bars aren’t parallel is what was causing your arm motor to burn out


The way you did compression was kinda monki too cuz it caused tons of friction by bending the gears and channels (and likely the axle). Next time I’d recommend just making the intakes mounted offset from the arm at the end of the arm.
Overall it’s a decent bot, I like how you used the trucks as both the bearing and the slide for the antitips. The intake lock was cool too

Now just make a gif of you doing the dougie and I’ll be happy

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Ah… negotiated ourselves down to a gif now have we?


Ohh my bad, thought it was powered on the bottom bar of the 4 bar not the top.

dont compromise for a gif Ethan, keep your eyes on the prize