Vex Iq motors are drifting

I have been working on a Vex iq robot for this years Rise above. it is already almost completed. But while practicing i ave one of my 2 drive motors that will drift at random intervals causing issues while driving. i have recalibrated my controller and brain but that did nothing. i am using the regular driver control already put on their by vex. any tips on what i should do?

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I’m not an expert but that sounds like a physical issue, most likely friction. Make sure that your 2 beams supporting the axles are right in line with each other. Also, make sure there is plenty of bracing


thank you for your input but ik that it is not the drive base build bc both sides of every axle are evely and well supported. there are many braces holding the 2 sides together.

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Can you explain a little more about what you mean by drift? Perhaps post a video?

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so basically the motors will start to move on their own without and input from the controller.

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I have had this problem with every brain when I am using driver control.

Recalibrating the controller sometimes helps (you could try it again), but since you already did that, I’d say that your best bet is custom code.

It drifts because it thinks that your joystick is not where it actually is, so it thinks that you are trying to make it go forward when you are not. With custom code, you can set the deadband to be bigger, making it not drift.

Just post if you need help with custom code.


Yeah recalibrating always worked for us.


I’ve had joysticks like that. In most cases it was because the roboteer was pushing the joysticks with lots of enthusiasm.

Before you calibrate, GENTLY roll the joystick around all the positions. Let it go, then roll it GENTLY around again. You are trying to get the stick to free up in the return motion.

In the calibration process gently move the joystick around.

Then gently drive it. If this doesn’t work, then you have a real deadband issue and will need to write custom code to have a wider set of values for the zero point.

Good luck!


Did you get your drift problem resolved?


well i went through a major rebuild ad i noticed while driving that it may be the way i drive. i tend to aways keep my thumbs on the joystick so i might have ben pushing it but i have not had much time to test this theory.


This is good advice. You shouldn’t always be pushing all the way on the sticks anyways, as there are lots of times it’s necessary to go slower than full speed.