Motors Slowing Down then Dying?

Today when testing our robot, the two 269 motors on our intake started to run significantly slower than before. We checked to see if maybe they had overheated but they were cold. To be safe, we turned the robot off and let it sit, but when I came back to it a few hours later the motors were still running slowly and after just a couple of minutes of running them, one of them died completely. We had noticed earlier in the year that they had slowed down a little bit, but this was significant and in a very short amount of time. We are using a side roller intake. Could this have occurred from simple wear and tear of in-taking and out-taking objects? Is there a way this could be prevented? This is a huge inconvenience for us because now we will have to wait until new motors arrive in order to properly test and program our robot.

What type of motors, 269’s or 3-wire? It seems statistically unlikely that both would die at the same exact time, have you tested them independently of the robot? If it’s a 269 then I just often (briefly) connect to a 9v backup battery to test.

Both are 269s. I edited my first post to reflect that. I haven’t tested them independently. I’ll go try that now.

I tested both motors on a new Cortex (different code), with new motor controllers, and I even tried the back up 9V trick you said (very quickly). All three workarounds didn’t help. One motor is completely dead (maybe twitching a little bit, but that’s it) and the other motor is spinning very slowly and appears close to dying.

Well they sound dead, better now than on April 19. Invest in a spare, they are only $12.99 :slight_smile:

Yeah we were actually kind of lucky because we had just bought new motors yesterday. We bought enough to allow us a spare for each side of the manipulator. Unfortunately they probably won’t come until Monday. But yes, better now than April 19th.

We have had 269’s die. I dissembled one completely and determined that it was the motor itself (not gears, PTC or anything else). I assume brushes in the motor wore out but I could not open it up to check despite trying hard to pry the back off. I also could not find a replacement part anywhere online so it just goes in the bin of spare motor parts.

Is there any way you know of to make them last longer? I have heard of one, but any additional preventative measures couldn’t hurt.

My mentor told me tonight that this year alone, our club (7 teams) purchased close to 50 269 motors. This is in stark contrast to the 10 393 motors we bought this season. I’m not sure if others have had similar problems, but we sure have not found any way to increase their longevity. Luckily they are relatively cheap, so its not much of a problem.

Take them apart and check the gear train. If the Dc motor is dead, you can at least salvage the case screws and gears for another motor.

We’ve had a 393 do this, but no 269’s yet…

Maybe we are just a little rougher on them.

We recently had this happen to one of our 269’s as well. It was a motor on our lift and we only discovered the problem after noticing the lift was going slower than usual, then checking each motor individually and finding out this one would not move at all.

My guess is that it is just regular wear and tear on the motor, but I would suggest examining the structure you are using the motor on to make sure there are no small defects that could put too much strain on the motor. In our case, we discovered that the motor probably burned out due to friction on the lift.

Just as an additional note, I noticed that some of our 269s have the number “10B10” printed on them while other, seemingly newer, ones have “1342B” printed on them. Is there a difference between 269s of these numbers? Both
(now dead) motors on our intake were “10B10” and they were relatively old so I would suspect that that number was printed on an older batch of 269s. Also I don’t believe we have ever had the “1342B” motors burn out. Every dead motor we have says “10B10.” Is this just because the"10B10" motors are older?