Compression Bars Prevent Arms From Lifting

We recently added compression bars for the intakes so they don’t spread outwards but we had an issue that we can’t seem to fix…When we have a cube in between the intakes and try to lift it, the friction between the arms and compression bars. However, it easily lifts when there isn’t a cube in between. Any way to solve this issue? (Also, we have added lexan on the compression bar but not on the arms)

Pictures would be great.

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I can message it to you…

If you can move the intakes slightly farther apart, do that, otherwise attach c channels to your drivetrain wider than the compression bars need to be, and attach the compression bars to those with spacers so they’re slightly wider than they are now


you need to spread your arm stops farther a bit, or more likely you need to brace your arms better. your arms should barely be flexing outwards when cubes go in.

a picture would be very helpful, just post it here instead of messaging it.


Ideally, better bracing for the arms so they don’t bend out. If you unable to do that, putting some grease on the compression bar could be a quick potential fix.

Though I don’t know if the grease is going to be a big enough improvement…you may have to just move the compression bars out and hopefully ur intake compression isint affected much.



yeah you need to brace your arms. try putting a c channel across both arms, you may have to tilt forward to lift your arms. this should also mean you don’t need those stops at all.

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All you need to do is make the c channels boxed up by pit two c channels together helps a lot with preventing flex. Also make a lock for the intakes.

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Ok thank you. Is there any way I could add bracing without having to tilt our tray forward? Just wondering if that much bracing isn’t enough…

Thank you, I’ll trying doing both possible improvements :slightly_smiling_face:

Send a front picture so I can see what the intakes look like relative to the tray and what’s the spacing

The intakes are hard-mounted, so they don’t swing open, meaning we don’t need any locks. Also, we did box off the entire arm of the robot, so yeah…I’m not sure what else needs to be done other than more bracing and grease


Don’t mind the bands on the intakes :sweat_smile:

You may need to brace the arm in the back in order to allow you to move your arm without moving the tray


So you can do bigger gears

Yep, we will add more bracing tomorrow…is 1x3 aluminum strong enough to prevent the arms from having too much friction against the compression bars/stops?

Would that help reduce the friction? Considering that the arms bend out wayy too much already when we intake a cube, increasing the sprocket size would cause it to bend even more…please correct me if I missed something

We currently have a boxed 2 wide plus two standoffs for our bracing, but you could try a 3 wide. It’s kinda up to how much space you have.

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Ok, thanks a lot :+1: