VEX IQ Claw Arm. Or moving up or down

Hello, we need help troubleshoot a possible gear/motor/programming issue. Our robot is functional and moves well with the controller. Except for the claw arm, which doesn’t not move.

When the control button is pressed, we. Hear a motor spinning sound and a flick and attempt to move up by the arm never actually moves up. Also out of two blue large gears only one side seems to be moving or making an attempt to move.

Please see attached video

(Sorry for the video quality, this was the only file extension we were able to convert to get the upload working. We have the high res video of there is a way to upload it on here.)

We are trying to isolate the problem and help or guidance on how to troubleshoot would be greatly appreciated.

You can use a personal gmail account and share to us the google drive file. Some pictures of the claw pivot would really help.

However, going off of what you said, it seems that only the right motor (treating the claw like the robot’s “face”) is trying to spin. Maybe try swapping out the left motor and see if that works? Or it may also be a build issue, so check the gear mesh (also try having those 2 motors spin 1 axle). If those don’t work, use some rubber bands to assist the motors.

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Hello Gigahertz, thank you for your prompt response.

Please find a couple of pics and a jump share link for the video. The red circle with an arrow is the motor we swapped. Although the arm didn’t lift, it seems that more thrust/torque was being applied.

Is it possible that the motor(s) is not configured correctly or setup on the wrong port? Or perhaps each motor is running opposite of each other and cancelling the spin?

We noticed that the arm would stop/stay in position when started from the top and the control button was continuously pressed.

Regarding the build related issues, what is the best way to isolate the problem? We plan to look into the small and large gear as well as the axle connection next. We will also run the motor on its own to make sure both motors are running as expected.

Should we change the gear ratio or any other config options?

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It looks like your arm is heavy. Have you tried using rubber bands stretched over the bend (elbow) of your arm to lighten the load / strain on your motors tryin to lift the arm?

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Thank you Rod, we will try reducing the weight and adding more assist through rubber bands.

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Hello All,

The problem has been fixed. We believe it was related to the programming and use of controller buttons. Instructions found on the following post has very good directions on necessary steps to move the arm up an down.

Thank you all for your help.

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