Clawbot Help


Hello Everyone,

We’re a school competition team and our competition is almost a month away and we’ve run into a problem trying to use the clawbots as part of the competition. The robot arm is no longer able to pick up the hexballs or move them.

Now, we’ve built these the year before and they’ve worked perfectly. We’ve tried updating the brain and motors and we’re still unable to get it to work.

I’ve attached a short video that illustrates the problem. Anything you can suggest would be greatly appreciated.


Here is the link:


Maybe the arm and the hexball are too heavy for your motor. If so you can change the gears for more strength.


Change that lift motor out. It should be able to lift it easily. The standard great ratio is more than fine.


I’ve tried changing the motors and even updating them and the problem continues.


Change the battery, also make sure that the arm can move freely when the robot is powered down (other than the force that the motor applies). It appears that the arm won’t go up even when it is empty!


Are you using the standard driver control program or your own program?


Standard program and the directions that came from the kit.


If you plug the arm motor into the claw port of the Brain, can you successfully use the claw buttons on the controller to raise the arm?


Sorry for the delay. I took one of them home on vacation to fix it, but I forgot the charger.

No luck with switching the arm motor into the claw port. The same issue persists.


I just realised that the Claw and Arm use the same bus, ports 10 and 11…
How about if you plug it into Port1 and use the joystick to move it? Make sure you are on 2 joystick (tank control) mode.


Alright, II removed all of the cables except for plugging in the arm with Port 1. I tested two motors. The first motor, nothing happened. The arm won’t move at all. On a hunch I tried a second motor. The arm moved up and down without the hexball, but froze in place after I added the hexball.


You are either unlucky and have 2 duff motors or something is wrong with the arm mechanism and its got loads of friction.


What do you mean by duff motors?


By duff I mean broken.