Intaking issue (compression wrong or bracing?)

Hello all! I have been struggling with my intakes. When I add a lot of compression, they twist, so they cannot intake cubes. When I lower compression, They still twist
In the dropdown are pictures of my bracing and intakes



@Doctortictac no offense but this is like your 12th how-to or fix-this topic and you should really try to fix some problems by yourself instead of just asking the vex forum.
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you might be able to fix this by adding some stand-offs across the arm or adding an extra bracing if the arm is the part that’s twisting. If the issue is the flip down (I’m guessing It is) you could tighten the hinge, add lithium grease to decrease friction, and make the spacers between the intake and the arm bar less (so put a piece of metal attached to the bar with standoffs firmly, and then put the hinge on the end of that piece of metal so there is as little distance between the intake and the arm bar as possible).


I have tried to fix this many times. The hinge isnt the problem. Its tight, and i’ve tried a lot. Also, what do you mean by standoffs across the arm?

where exactly is the problem? Is it with the bars on the arm twisting, or is it with the intake rollers on the hinge twisting?

Like @Riptide said, it is an ancient vexforum curse: everytime you create a new topic something goes wrong with your intake.

You need to flip bearing blocks to the outside of the channel and use two screws with shaft going in center hole. Everytime you increase compression the friction is killing the motors.

Then you should replace 6t sprockets with something larger like 18t.


Try adding supports on the other side of the intake rollers so that they arent cantilevered.


Is there a reason for this?

That part isn’t compression, and they’re 12t. I was having trouble with intake efficiency (could only intake head on), and I swapped to those as they could grab the part of the cube that could intake it at all angles.

The friction between what? Im adding spacers between the intake and the arm.

oh no

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do you mean the channel attaching them or the rollers themselves?

Think by six tooth sprockets he/she means the ones chaining the two rollers together

Ok. Does @Illyana mean to chain diff sizer for speed.

also based on her responses, she.

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Yeah I had it as she but then doubted myself and decided not to assume an internet persons gender. Cause assuming anything about an internet person is a bad idea


This isn’t necessary. It’s still possible to screw bearing blocks on the inner part of a c-channel flange.

I think the real problem is there is no support on the underside of the sprockets and you have an unnecessary amount of chain. Just link the two intake sprockets completely with tread, don’t isolate each sprocket. Get rid of the top chain that is linked with 6 tooth sprockets and condense your entire intake. I think if you remove those excess sprockets, your intake will fit in the same footprint it currently does while also adding supporting c-channel. Moreover, the only reason to isolate a sprocket is if your chain breaks frequently and even then you’d use gears to link the intake sprockets, not more chain…

Overall, your main problem is friction as far as I could tell. You shouldn’t force anything into place nor should the robot force anything. Everything should be very fluid. No c-channel should be bent and everything that needs to remain stationary should be connected at at least two points with nylocks (unless you have a good screwdriver, then use keps). The images you provided show that your robot is inherently asymmetrical and full of friction. I think this robot could be very competitive it there was more attention to detail, but unfortunately there isn’t. Consider rebuilding and replacing some of the broken/misaligned parts that will only cause you headaches.

This ties back to this issue:

Clearly you’ve had the same issue for months now. At some point you just have to do something more simple that can actually work and build up from there.


This new design is better in the way that the chain will not break and it adds better power as you can tune intaking and compression differently.

My compression now is high, (4 ish inches), and when I reduce it to 5 inches between compression sprockets, they fail out and can only intake about 4, and the cubes fall out because of the weight

You could try to argue against my suggestions but your robot is the one that isn’t performing.

Once again, your intake uses chain to link the sprockets, essentially defeating the point of isolating the sprockets.

Elaborate? What do you mean it adds better power? Look at 6842z (pigpen), they have a very simple, traditional intake that’s super powerful. Some of there match footage is online as well as there 126 point skills run. The fact that your intake is struggling to transfer power effectively isn’t helping your argument either.


Please, do not roast me. This is a nice forum.

As for pigpen, I cannot see their bracing, therefore I do not know how they do it. The traditional chain will break. I’m not saying I have anything against it, but I swapped to the “china style” intakes.

Could you elaborate on where you see this?

The top sprockets don’t even have the same size spacers between them and the c-channel. I don’t see any washers anywhere. There are screws visibly loose. There is c-channel visibly mangled. In another photo, your battery isn’t even attatched to the robot, and there are loose cables begging to get caught onto something.

They have bracing on two points I believe (as do most other competitive robots). One at the pivot point where the gears power the arms and one in between the arms under the tray. The bot just seems super rigid which is what you should be going for.

You don’t need a china style intake or anything like that. You need to focus on getting something working. I’d even advise you eliminate the two sprocket system altogether and just use one sprocket directly driven by the motor as an intake. I’ve seen this work well for 7 cubes which is more than you can currently do I believe and is simple enough to engineer. Right now you have too many variables working against you.


I will do this tomorrow. Thank you for the advice. Also, I can do 8 cubes

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You didn’t say you could do 8 cubes before, or am I mistaken? Either way, small tweaks go a long way. Try to focus on symmetry and rigidity.

These actually still aren’t the china style intakes…
I’ve already told you this but China-style intakes have 2 rollers that are the same size and they are staggered. They also have the Inside rollers at 100 rpm, and the outside rollers at 166rpm.

The rollers themselves.
Like this