Falcon 500 Magnets Shattered

For this year’s robot we are using a Falcon 500 to directly drive our shooter. It was mounted securely, but still had a decent amount of vibration while running. This is only the second year we have used Falcons and had already completed one competition. During testing the week following the competition the motor suddenly seized up. After much pain, we disassembled the motor and discovered the if the magnets had shattered and chunks of magnet were wedged in the stator. The following are pictures after dissembly:




Any thoughts on if this was a fluke before we just replace the motor for our next competition?

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You should contact prosupport@vex.com immediately.

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Just out of curiosity, have you confirmed that all the shaft screws are still in place? I wonder if one could have backed out and dropped into the rotor and caused the carnage.

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Looks like the face of the motor failed causing the damage. Perhaps it was overtightened and the vibration then maid it fail.

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That was our first thought. All the shaft screws were firmly in place.

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The CD community might be able to help more if you post a picture of the shooter, showing how you directly coupled a Falcon to the wheel.

As Paul suggested, prosupport@vex.com is your absolute best resource for any issues with the motor.

/edit: I looked up your team’s matches on Youtube, after failing to find any data on TBA. (Apparently there was some FMS difficulty at CHS Greater DC Event#1 Day 1.)

Congratulation on your Blue Banner with the #1 Alliance! That was some impressive defense.

Hard to see details of the shooter in those videos. It is possible that vibration caused by an unbalanced flywheel (the large black wheel seen in the fuzzy shot below) might have been transmitted back to the Falcon bearings and mounting plate, accelerating fatigue. Some teams have coupled their shooter motors to the main shooter wheel shaft using a belt (even if the ratio is 1:1) as a method of decoupling vibrations from the motor.

image

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Sadly I didn’t think to take any photos of the mounting before I left. A quick explanation of the mounting is the motor is mounted to the box channel at the corner which you can kind of see in the photo on the opposite side of the flywheel. The falcon has a spline to hex adapter and then a large hex coupler connecting that to the shooter shaft. Ideally we would have a short belt drive, but we have a competition on Saturday so there isn’t much time to get that reworked. I’ll make sure to reach out to Vex regardless.

That is going to be impossible to keep everything concentric, so it will place some serious side loading on the motor’s shaft when spinning at top speed and even more side loading when a ball is introduced.

If you have a double bearing mount you can use that to create a gear to gear drive so that the shaft is supported by its own set of bearings instead of the motor’s bearings.

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