Neo's very hot. Is this ever normal and would it make the motor slow down

We have one Neo powering an arm with 100:1 gearbox reduction and ?3:1 sprocket reduction. We’ve been running it for a few weeks without problem and never felt to see if it got hot. Today the coders were modifying code while working on a limit switch on the arm and may have stalled the Neo. I’m not sure if there is current limiting. At one point the motor was moving very slow so the coders switched back to the old code and it was still moving slow. We tried to look up how a Neo behaves when it gets very hot and whether we could have damaged it but are not finding anything except that they can get fried and stop working completely.

One way to check whether a Neo (or any motor) is damaged is to take it off your mechanism and unplug all the wires. When turning the shaft by hand, the shaft should spin freely (with only the resistance from the magnets). Also try running the motor with nothing on it. It shouldn’t get hot when not under a load.


I would also try running it from the REV client by itself to see how it reacts. Unfortunately our NEO’s haven’t faired well this year when they have encountered this same scenario.

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We’ll try that. When you have damaged a Neo in the past, do they just stop or do they slow down?

We smoked ~2 neos on our intake to hold in cubes and cones and switched to falcons yesterday. Although the neos have a thermometer built in, the thermal protection isn’t very great since the data lags behind. It does has “smart current limiting” through the sparkmax though so might be good to check if you configured that right. Def check the rev Neo Locked Rotor Testing for more info.

Regarding the motor slow down though, the torque output is going to be relatively constant until it falls off a cliff and fries itself so unless that happens you should be fine in terms of motor output. (check the graphs in the previous link)

If things get hot check to see if it spins freely by hand (with magnet resistance, as said above)

Excessive heat can cause adhesives to fail that hold internal magnets in place.

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Here’s what we discovered. The motor was damaged, probably from being stalled. It moved, but still moved slowly when it cooled. The shaft was notably harder to spin manually. We did not take it apart yet.