Help with Motors Pls

I’ve got 7 VEX IQ motors at home. 6 of them are about 5 years old and I don’t know about the other because I got it from a coach. For some reason 6 of the motors are slow and lack power, while one is much faster and powerful. For example, I’ve tried building robots on YouTube before and for the drive train I use the same ratios and they refuse to turn, or move very slow unless I use the good motor. Do I need to buy 5 new motors (they’re expensive!) or is there anything else I can do? Please help.

have you checked the friction on the setup? idk much about vex iq but friction can always play a role in things like power loss

Yes, the drivetrain isn’t the problem I’ve checked it many times. It’s just the motors, one moves way faster than the other 6.

if it’s not a mechanical problem, and not a problem with your code

you’ll likely need to just buy new motors unless you can fix the current ones. they sound kinda dead lol

You’re probably right. Just thought I’d post something to make sure because I’m reluctant to spend money on motors. 5 motors is over $100.

just wait till vrc lol it gets even worse

$40 per + extra cartridges

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Yikes. I’m doing VRC next year

But by then I won’t have to pay for things. I’m doing my own team this year with my brother because of coronavirus.

robotics is not a cheap hobby unfortunately


If those are non-competition motors you can consider repairing by cleaning and re-lubricating them yourself. This topic talks about opening IQ smartmotors:

Maybe you could attempt to take apart the motors and fix them but I wouldn’t do that without knowledge of vex iq motors.

If at free speed one moves faster than the others, try switching the ports to validate that the problem isn’t the VEXIQ brain. If you can see the newer motor still spinning faster than the others, then you may just need to get new replacement motors.

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This seems unlikely. IQ motors are I2C, the Brain just sends a signal saying hey, go this fast for this distance.
The motor handles the rest using the internal encoders.
One good test is to put a gear or similat on a good and bad motor with nothing else. Put a pin in as a marker and set the marker to the same reference (say 12 o’clock) on each.
Now program both to move 360 or 720 degrees at 100% speed. Do they both complete the movement at the same time and was the full amount completed on both?


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