then assemble the motor again and checked how the motor is spinning (we didn’t check with a electrical Circuit, we will check In the coming days and update you how the motor works)
I am really for interested for if/how the motor will spin after you take it apart because now the factory calibration is messed up. Just for reference what version of Falcon is this?
The likely answer to this question is “not quite as good as a factory new falcon*, but better than a motor with metal shavings in it”
* a purely theoretical object at this point
There is a calibration done in the factory between the angles of the hall effect sensors and the motor phase windings. The ability to recalibrate isn’t exposed to end users. Getting that angle exactly correct is important for getting 100% out of the motor commutation, but the motor should still spin even if it isn’t exact.
We’ve even done a “brain transplant” between one electrically-damaged Falcon and one that was mechanically-damaged in order to end up with one working motor. The Frankenstein motor works, though likely not at 100%. It’s not something we would put on a competition robot, but better than two paperweights.
I Frankensteined two falcons, one with a bad stator and one with a bad motor controller. When you try to run the motor, it will only spin at 100% speed.
The motor is now clearly labeled as NOT FOR COMPETITION USE.
For future reference there is a falcon V3 teardown guide on frczero.org I had a similar issue with a rattling falcon, I didn’t fully remove the encoder and MC from the back of the falcon so it still worked after the fact. It was more like disassemble everything except that connection point. My issue ended up being an encoder spacer was not on a bolt where it belonged
The Falcon uses a magnetic encoder, not traditional hall effects, so the commutation can be pretty far off and not spin the motor at all. FOC won’t even come close to working.
information about the exact process for Falcons is not public information, but we can glean the basics from how CTRE is handling the new Krakens that use the same MC. The final assembly process is being done by a robotic arm.
Also this quote from CTREs website
Imported from Detroit
Every single Talon FX PCB assembly is built on the electronics production line at the CTR Electronics HQ in Macomb, MI.
Additionally, CTR Electronics added an automated robotic assembly line at their HQ. This line will be used for final integration of the Talon FX and Kraken X60, ensuring quality and consistency during critical steps in the manufacturing process.
Furthermore, 100% of these units go through final QA testing and validation in Michigan before being shipped to customers.
I wonder if CTRE would be open to releasing some info on how Falcons could be realigned, or if impossible, at least an explanation as to why it could never be possible to an end user.
If they did it with some mechanical or electromechanical jig, I could see how an end user couldn’t replicate the process. But if the motors have phase voltage sensing (I hope they do, at least), it seems like it should be possible to spin the motor at a few roughly-constant speeds and have the controller capture the relationship between the back-EMF and the encoder position.
I would be surprised if they ever released that information for multiple reasons. First discourages that level of disassembly. The falcons are sold as “no serviceable parts inside”. I have a few others that requires assumptions of CTRE’s mindset.
It’s fairly straightforward to do the calibration on a normal FOC motor controller, and probably could be done with a button in Tuner. However, there aren’t any spare motors or controllers to replace dead Falcons, and there’s a lot of pieces in there that could be installed improperly during a repair. Users would need all the replacement parts and the ability to diagnose the issue, and even then their refurb motor may not work if one of the parts is assembled wrong. The design just isn’t made to be repairable, at least from what I can see in teardowns.
I also don’t see CTRE or any FIRST vendor wanting to be responsible for selling spare parts that “don’t work” because a team missed a step in the process. Even when the part isn’t faulty that will force more support calls and requests for help with it. Easier to just sell full replacements. I agree as the end consumer it sucks, but for the company it’s way better. They can ensure and guarantee their processes in house, but don’t want to give teams a possible footgun outside of their control
