Clawbot claw not opening

Two students in my class have hit a problem with the claw on their clawbots. Despite their batteriesa being fully charged and the drivers being only a few feet from their bots, pressing the “open” button for the claw on an unmodified clawbot fails to open the claw - nothinhg happens. Giving it a bit of help doesn’t work, either. Powering off the Cortex and the controller and turning them back on gets things going again. The claw makes no sound during this, no hum, no spinning, no grinding. All the connections are good and checking them n the usual ways also doesn’t fix the problem. Ideas, anyone?

since none of your details seem to cause people to even come up with a solution (including myself) because all you really said was just a general statement saying that your claw doesn’t open… anyway if what I’m getting at through your description is a curate that it isn’t the build that is the issue, then there are only 2 possible things that I can think of that might be the issue.

  1. motors are dead in some way
  2. programming

If you are following the default/pre installed code:
Make sure the claw is connected to port 6 on the CORTEX

If you are following a code that you installed from ROBOTC:
Double check to ensure that the that the 3-pin wire is on the same port that is shown on your motors and sensors setup, double check if you need to.

Check to see if the two-pin connector from the motor to the motor controller isn’t unplugged.

Edit//: Otherwise it is either a program error or the motor is dead.

The students are using the default code in the Cortex. The claw is connected to pin 6 and is driven by a 3 wire motor. It will work for several mins before it decides to stop. Turning the Cortex and the bot off and on again will restart it. Most odd behavior.

It sounds like the kids might be ridding the close button a little to long. If the motor is stalling out it will not work until it cools down. When the claw stops working feel the motor. If it is hot then tell the students they can’t hold down the button while the claw is fully closed. It sounds like the motors might have time to cool down while you are turning the cortex on and off.

You can try testing the motors separately, outside the mechanism. What we do is we have a breadboard that we use to test motors whenever we have any doubts at all. Otherwise, you can try rewriting the program.