Hi,

I'm using Betaflight 4.4.3 on Speedybee F4 V4 FC. I've setup 'Arming' to Aux 1 of the controller. But as soon as I Arm, the motors start spinning rather pretty fast, instead of start to spin with the throttle. Need help to fix this.

TIA

If you are testing the motors with props off on the bench then that behaviour is completely normal and is to do with the PID controller detecting no expected change in attitude of the quad as the motor RPM is raised, so it keeps raising the motor RPM higher and higher to try and get the quad to lift off the ground because it thinks there isn't yet enough thrust to do so which is why your motors can appear to behave erratically or spin up to max RPM by themselves. Have a watch of the following video to understand why. To get proper behaviour you need to put the props on and take it outside for a hover test. You will then find that the motors behave as commanded by your transmitter.

If, on the other hand, the motors spin up with the props mounted, it could be a problem with motor vibration getting into the FC through the frame.

If you test the motors with the props mounted, ALWAYS hold onto the drone by hand.

I had this problem with a 2S build on a too-flexible frame. Upon arming with throttle at minimum it wanted to shoot to the moon. The solution was to add some rpm filter by moving both sliders to the left, from 1.0 to 0.8.

The better solution was to throw away that frame and use a stiffer one. Filter back to 1.0, and it flies well without firing for the moon.

(14-Mar-2024, 01:46 PM)segler999 Wrote: If you test the motors with the props mounted, ALWAYS hold onto the drone by hand.

Just to add, NEVER do this with a 4" or larger quad. I probably wouldn't even do it for a 3" or 3.5" quad either. It only takes one thing to go wrong and you could end up making an emergency trip to the hospital.

If you test with props on, do it outside and stand well back from your quad with a finger over the disarm switch ready to turn off the motors in case it tries to fly away to the moon of it's own accord.

(13-Mar-2024, 05:58 PM)SnowLeopardFPV Wrote: If you are testing the motors with props off on the bench then that behaviour is completely normal and is to do with the PID controller detecting no expected change in attitude of the quad as the motor RPM is raised, so it keeps raising the motor RPM higher and higher to try and get the quad to lift off the ground because it thinks there isn't yet enough thrust to do so which is why your motors can appear to behave erratically or spin up to max RPM by themselves. Have a watch of the following video to understand why. To get proper behaviour you need to put the props on and take it outside for a hover test. You will then find that the motors behave as commanded by your transmitter.

Thanks, that helped.

Yes, I'm testing the motors without props on the bench.

P.S.: It was good to see Joshua with some hair