Angry Shooter Noises

Robot is making a very squeaky noise. It is our shooter.

That’s definitely the Falcon. That’s a known noise when you stall a Falcon.


How can I fix it? It even happens when driving at low speeds.

Its a feature


I understand that but why? I don’t want it to do that… I set it to .8 it won’t shoot

There seems to be a rattling sound and it sounds like unhappy falcon shaft retaining bolts before the stalling. Unless all that’s coming from the chain…

What would we do about that? Our drive motors won’t work now

  1. Take the falcon apart and check if anything is loose.
  2. Check for all the set screws and if there are any are missing that someone didn’t remove, it’s probably in the motor.
  3. Email VEX PRO because we aren’t their customer support and can’t give you falcon parts if anything is broken

Wait back up…what on your robot is currently driven by Falcons?

What is the clicking noise from? Is the clicking noise from a mechanism with Falcons?

Are your motors set to spin in opposite directions? (I’m assuming you’re using 2 for your shooter).

If one isn’t inverted they would be trying to spin against each other.

Nope, we are only using one currently. Our Drive has 4 falcons, two of which are doing the same thing, the other two work perfect, 1 and 2 are fine, 3 and 4 are not. The shooter is also very much not ok. They arent working against each other as it was working fine this morning.

While you might think these motors have a lot of power it doesn’t take a ton of force to keep them from starting up. Check the set screw for the air vent. Can you use your hand to spin the system yourself? We found that to much friction on the motor can cause it to not begin to spin.

We found the issue WAS the air vent set screw…


The noise is due to the magnetic fields around the individual loops of wire in the windings interacting with each other and causing the wires to move. The motion occurs at the frequency being fed into the motor windings. You will hear similar noises when an electric bus or subway car starts moving. The windings are usually impregnated with varnish to minimize this but the audible noise will still occur when high currents are flowing through them i.e. stall condition. There are a couple threads here where this “feature” is exploited to make “music”. If you don’t like the noise, don’t allow the motor to operate at high currents. Other than taking care of motors fighting each other or screws jamming the rotor, this means not operating the motor near full power output.

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i know this is not at all related to topic but what were those treads you guys are using to move the ball up into the shooter ?

I’m the programmer so I’m not 100% sure but the builders had said they were tank tracks, they use these sprocket like objects to turn them. I will find out exactly what they are in a few hours!

Check the length of the mounting screw. The screws that come with the Falcon are a few MM too long and when you tighten them up real good the tips dig into the stator. We used shorter length screws and that fixed us up on the drive motors. If you open the housing the strong magnets will attract any steel object that is near. Those little set screws are prone to get zapped and stuck to the inside of the motor.


Sounds like Iron Man powering up his photon shooters

The falcon chirps