Jd Gripper - Defective Part


I just got a JD Revolution robot today for my robotics programming class. I assembled the robot and ran through the tutorials. When going through the initial tests with the robot, I noticed the right gripper servo would not move. I have checked the connections and everything else on the robot appears to be working fine. Would this be a defective servo in the gripper, or could it be something else? My class enjoyed experimenting with the robot today and we are excited to see what we can do with it over the remaining few weeks of the semester. Thanks!

Chad Andrae


Great to hear they're enjoying the robot. If the gripper did not operate out of packaging, then it indeed is a rare defective servo motor. Please Contact Us for warranty and provide a link to this thread topic for reference.


I would create a new EZ-Builder project, and just create a servo object for the port the gripper servo is plugged into, and see if it moves when you set the min and max values for that port. Then try unplugging the gripper and plugging into another port (maybe one that you know works already) and re-define the servo object and see if it works. Also try a known good servo on the gripper port.

It could be a bad servo, bad port on the EZ-B board, or bad connection. One of my EZ-Bs has one bad port (I accidentally shorted it out with a screwdriver). so determining where hte problem is will help determine if you should make a warranty claim (through the Contact Us page) and for which component.

Also (and maybe first), make sure the screw that holds the claws on the servo is not too tight and causing it to bind.

If you do determine it is a bad gripper servo, I have some spares and could loan you one while you get the replacement sorted out. (my email address is in my profile).

In a school environment, you might want to order in a stock of spare parts. Servos are wear items and are not warrantied other than out of box failures, and they can burn out. Students can be particularly hard on robots in general and servos in particular. Brookstone currently has some great prices on their remaining stock (including rotation and gripper servos, so you could stock up. Unfortunately, they are out of lever servos which are most used in JD. http://www.brookstone.com/search?q=ez-robot



Thank you for those suggestions, Alan. I will work through those trouble shooting steps tomorrow and then submit the warranty claim based on my findings.

I hope to get some spare parts, but school budgets tend to be tight. Thanks again for the information.



@Candrae, are you working with any education dealers/distributors of ez-robot? If not, it may be a good idea to Contact Us or your retailer to get advice on what parts to stock for specific robots. They should also be able to assist with curriculum as well