Delta II | 6000+ Motors Burning Out Too Fast

In my recent competition, which was regionals, we were encountering some issues.
At the beginning 3 qualifying matches, we were undefeated and demolished the enemy teams. But afterwards, every other match our motors on our lift locked up on us, which made us lose. We then went down to 30th place(or something like that) and we were never picked because we were considered unreliable. But luckily, we were able to get design awards, which allows us to go to worlds. This wasn’t just me who was having the issue, almost more than half of the 400’s were too. My suggestion to EVERYONE, is to NEVER BUY a motor with a serial number of 6000 or higher. They burn out really quick and they are extremely unreliable in-game. It is best to buy motors with a serial number between 5000-5999 because those types burn out much less, and are just as good at performance. VEX, can you please fix this burnout issue with the motors?

The serial number is found boxed in on this picture of a clawbot, which shows a motor which I consider good:

What defect in the motor do you think causes the extra burning out?

I have no idea, but I have considered two options which lead to this:

  1. The motors heat up way too fast, or
  2. The integrated chip that prevents the motors from heating too much or breaking is faulty.
    EDIT//: Most probably I think it’s the integrated chip (PTCs, which was stated by mwang17)

If you have the right equipment (soldering iron and solder), you could transplant the PTC thermistor from a ‘good’ motor to a ‘bad’ motor and stress-test it; that would eliminate/identify the PTC thermistor as the cause.

Of course doing this would make all motors involved not legal for vex.

Sadly this is true. So, perhaps choose a broken 5000-5999 motor to do the testing (you probably won’t care much about the 6000+ motor).

What makes you think that it is only motors with a serial number between 5000-5999? Do other motors not stall on your lift?

I’ve recently purchased several new motors in preparation for regionals and several had a different sound when running full. I opted to stay with old motors.

We havent had that problem yet but congrats on your design award i was your alliance for your first match. Yall were doing good in the match.

Well… It can be below 5000 but I don’t think it’s best to, since those motors can wear/decrease even if they don’t even run due to corrosion, etc…

Thank you very much! I really enjoyed the first match with you also!

our new motors also make a new sound, didn’t affect performance tho

they also have a new dimple on the front top side

The change in sound is an indication that there has been some change to design/materials and/or process. At this point it’s just another piece of information that should be considered. The change causing the sound difference may/may not related or there maybe a common root to both the sound and performance differences.

its probably the waterproofing

My team noticed this too with the new motors, they seem to run a lot smoother and make a very different sound.

Yeah, the 6000-6999 motors definitely run smoother than the 5000-5999 motors. But the main issue is that they lock up extremely fast after only mild use over time. I think this is happening to some of the 6000-6999 motors, but just to make sure, I recommend 5000-5999 type motors. My claw is currently using 6000-6999 motors, and they lock up extremely fast, so I divided the motor power by an amount of 13 to make sure they don’t have the issue that frequent, but yet they still lock up over time.

Good thing, I had a clawbot at home with barely used motors that are in the range of 5100-5200. So I will most probably be putting those motors on my robot.

Getting ready for next year’s game.

Water game?