Defective clutch on motor/servo?

I found out that one of the clutches on motors and servos may be defective. If I pull the clutch out of the servo, the square hole inside the servo is at its center. If I put the clutch back on the servo, the clutch’s square hole is about 30 degrees off center. Is the clutch defective? Can I fix it?

It might’ve just been a defect. When our team got the kits, we never really noticed that. I believe that they also come with an extra clutch or two, so you could just use those.

But if you’re talking about the square holes not lining up, that’s normal. It’s a clutch, it’s doing its job. The clutch is the connection between the output shaft from the motor/servo to the shaft that goes to the gear or wheel. When a certain resistance is applied onto the output shaft, the clutch would disengage and the motor would not burn out or strip an internal gear or two.

That’s sorta a basic explanation of what the clutch does…

Hope that helps.

The kits don’t have extra clutches. There are bags of extra gears that go inside the motors and servos. I know that a clutch is supposed to disengage the wheels and gears from the motors and servos if a robot hits the wall. I put gears on both sides of the clutch and tried to turn one of the gears but I couldn’t do it. Any suggestions?


Your prayers have been answered! Whitney High School gave a VEX Robotics summer camp and our kids burned out a number of clutch assemblies. When I tried to buy replacements, I found they were unavailable. Solution - we talked to the wonderful folks at Radio Shack (Education Division) and they have promised to start selling clutch assemblies as of November 1, 2005 (or thereabouts). They needed a couple of months to design packaging, etc. The price should be in the neighborhood of $2.50 to $3.00 each.

Check out the website after 11/1/05.