Claw bot arm sag

how do you program the arm so it will not sag on a modified claw bot

Could you post pictures? Is this iq or vrc? Is the arm too heavy? Metal bending? Please elaborate

I think he is referring to Vex IQ.

We still need elaboration on this.

Carcar, It has a tower takeover tag

For the topic, use PID.

PS tons of people have the iq chat muted. Make sure ur in the correct category to get proper advice

Sorry I didn’t read it carefull, I will do so next time.

We are Middle School and competing in VRC and using EDR V5. We have built a modified clawbot and when we pick up the block and move to scoring box the arm slowly drops down to the ground as we are moving. How do we add to program to keep tension on this without holding down a button to keep it up? My teacher/coach called it arm sag.

wait i can mute iq so i just see edr

yeah if you go to each IQ category and mute it… good luck with that though

yeah thought there was going to be either a catch or a long process

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I don’t know why anybody would want to. VIQC is far superior to VRC.

cause sometimes the people that r in vrc will be accidentally talking bout vrc in an iq thread like i believe carcar did then everyone be confused why he saying stack blocks when iq does balls (using random example)

This could be weight of the arm.

spinTo might be your friend here. The next step up would be to occasionally check the motor’s position and spinning it to the difference between your target and your current position. ie k*(target-current) where k is a constant that you set. (this is called a P loop)

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good meme.


Very good. Very funny. VIQC is inferior to VRC

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since they’re using v5, they could just use motor hold instead of using a P loop.

Are you using VEXcode Blocks or Text? In Blocks, you can set the stopping mode of the motor to hold to have the motor use it’s mechanical strength to keep the arm in the air.


In text, you can use the setStopping command.

  ArmMotor.spinFor(90, degrees);

Thank you we got it, it works well now

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