Issue with Stacking

VEX Robotics Competition Discussion VRC > Tower Takeover (19/20)
#1

Hi so our team have been having issue with stacking.

Namely, we have enough compression to get 8-9cubes, and the arms are sturdy enough that they dont warp naturally.

However, when we try to stack, the problem is the arm continues to hold on to the cubes, meaning we can’t just back out of the stack. Instead we have to outtake and backout at the same time.

We’re wondering how teams have made their compression “variable.” IE: high compression on intake, low compression on stacking. I saw some teams add hinges such that raising the tray will passively push the rollers away from the stack, decreasing the compression. Does anyone have experience doing something similar? Would love guidance and pictures. Thanks!

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Intake Compression Questions Thread
#2

What I do is I make the intake rollers close enough to the tray so that when the tray moves forward the rollers split apart.

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#3

We are currently having the same issue. Our plan is to make sure we can pick up cubes, but enough for it to be pushed up. Also, the motors that push tray up could become torque motors instead. Also this thread shouldn’t be labeled as chitchat.

#4

Does it move apart because the arms themselves are twisting? Or is it moving ona hinge?

Need help with intake rollers
#5

I don’t have arms because I have a simple tray, but no, It doesn’t move on a hinge, It is on stand-offs that just get pushed out when the tray moves forward. right now I’m rebuilding my robot so it’s less jank but here is a pic of my jank early season intake (please note a lot of the robot is recycled from Turning Point and In The Zone).
image image

#6

You could just back out and turn the rollers at the same time, unless theres something stopping the rollers from turning.

#7

You could use string or some sort of mechanism that will slowly pull away the rollers when stacking, or you could code a function to do the stacking part for you.

#8

Thats an option we’re considering but we would rather solve it mechanically

#9

Can you elaborate? Do you have any pictures?

#10

This video is where I saw the string idea.
And about the function part, I was talking about creating a function that does the placing and backing away part for you. For one, it reduces the driver’s nerves as well as allows for consistency by just allowing you to line yourself up and allowing the robot to finish off the job for you.

#11

Our intake is pushed apart by the tray, but then we lean the tray back, and push a button we programmed to run the intake in reverse slowly so as not to pull the stack down when backing off. Super easy to program, so a good quick fix.

#12

Sorry to necro, but we’re trying this approach now, but do you have hinges like 1961Z does in their reveal?

#13

Do you still need help with hinges?

#14

Just out of curiosity, why are the high-strength axles zip-tied to the frame of your robot?

#15

Those were counterweights that I used because that was a very jank early season bot with a recycled chassis and it tipped back even with an anti tip making auton a little inconsistent.

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