Potentiometer repair

So this is technically illegal for a competition robot, however, not everyone builds competition robots so it’s worth knowing.

The school has some potentiometers that don’t work well anymore primarily due to inadvertent continuous rotation. I also had one that was bad straight out of the box, it gave an incorrect reading part way through the range. Although they are not expensive, it’s cheaper to repair them.

The hard part of this process is opening the potentiometer enclosure, I used a small flat blade screwdriver and pried them open on the inside of the slot where they are normally attached to the robot.

Once open they look like this.

I found replacement parts at Mouser.

Part number 531-PT15NH-10K

The data sheet for this part is here.

I bought 10 for less than $5 (excluding shipping).

Parts ready for installation.


Remove the pot completely from the housing, desolder the old pot, solder in the new pot with the wires in the same order. I trimmed and flattened the leads for the new pot before using it, normally this component would be installed in a PCB so it’s leads are designed to hold it in the board prior to soldering.

Here’s a comparison between original and new part.


Put everything back together, make sure the cable relief is in its slot correctly. I used a small amount of plastic model glue to hold the two parts of the cover together.

Takes about 10 minutes.


Wouldn’t this be legal according to R7?

Can’t see how this wouldn’t be identical. I’m gonna ask in the official Q&A.

Also, many thanks for the instructions :). We have several potentiometers which could use fixing.

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I was concerned with R15

<R15> Parts may NOT be modified as follows:
a. Motors, extension cords, sensors, controllers, battery packs, and any other electrical
component of the VEX Robotics Design System may NOT be altered from their original state in ANY way.

Repair is a grey area, a skilled repair to the potentiometer will not change its performance or be unsafe in any way. A poorly executed repair however, who knows.


Hm guess we’ll have to wait for the official ruling. I just don’t feel like that’s really “modifying” the component.

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I haven’t seen anything answered in a while, I guess Karthik is being kept busy preparing for the seasons start.

They’ll all get answered in one big shot like they always are

and if you ever wondered what was inside a potentiometer…



That actually makes alot of sense. It’s a much simpler part than I was expecting.