New Falcon Failure Mode

Has anyone seen a falcon fail like this?


how did this happen?

Not sure. We took it off our drive base since the shaft was wiggling and finally got around to disassembling it. We found during disassembly everything else on the motor was fine.

Vex engineers rn:


Add it to the list :clipboard:


Stoked to see the removable speed controller option!


This happened to us once. The cause of the failure was a missing nose bearing. I’m pretty sure it was our fault. I’m guessing the nose bearing fell out when the motor was disassembled to add thread locker to the shaft screws.


Could this be a failure mode if you put too much press force on the shaft when pressing on a gear?

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Eh, it’s Saturday. This sounds like something to worry about on Monday after a surprise meeting that could have just been an email with a link to this thread!


Please send an email to

Let’s get this figured out and remidied.


This REEKS of Monty Python writers… LOL

We’ve had two falcons in the past year fail like this too.

We’re they missing the nose bearing? Did they take any noticeable impact loads?

Not sure. Whenever theres something weird going on with a falcon I end up taking a look at it.

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That’s very interesting, where and how it broke. I’m curious what the temperature of the cast end plate (assuming it’s a cast metal plate) was right there where the wiring connections were when it failed. Obviously, that’s not something you’d have, but I wonder if the heat being generated right there had any impact on the failure.

I should say that I have never had a Falcon in my hands to see how they are constructed. This is just an observation based on that picture.


We are pretty sure that bearing was in the motor but will double check on Wednesday.

We have had a falcon snap it’s face plate, due to the stress it was under I guess, although it was not under much stress. Think another robot may have hit it.

We have also destroyed a kit of parts chassis wheel at the same event:

First impression of the broken Falcon end plate surrounding the bearing: The fracture shows two ‘lobes’ adjacent to and below the bearing which suggest at least two fatigue fracture origins in the casting at the bearing hole. A more detailed investigation and analysis would be needed to confirm or disprove.

Wow, to break a wheel like that suggests pretty severe impact either from a high speed collision or dropping the robot on the side of the wheel. The break in the falcon end plate suggests a high cantilevered load on the shaft.