Hi, I don’t know if you’re still facing this issue but I faced something similar. I will share my solutions here in case anyone else has a problem with the same platform.
My configuration:
X650 ARTF Kit
Pixhawk 6C flight controller on Arducopter v4.5.2
6S 8000mAh battery
Radiomaster TX16S MKII with RP1 Nano on ELRS
My process and symptoms prior to the fix:
- Performed all necessary initial configurations and setup
- I tested all motors without props via the mission planner motor test function
- Tested one motor with a prop with UAS secured, worked fine
- Took UAS outdoors to prep for first flight, hit approx 50% on thrust stick of R/C and the props sounded like they weren’t speeding up beyond this point
- I gently pushed the thrust stick all the way to max but the platform didn’t shift (maybe only a little tilting about)
At this point I verified that all motors were spinning in the correct direction, I used motor test to make sure the right motors were being commanded, I did some low power ground tests to verify correct response to roll/pitch commands, all was fine.
I did some more ground testing and did a motor test at increments of 10% - I noticed that after 50% command, the prop sounded like it was saturated (i.e. when I commanded 50%, 60%, 70%, the prop made the exact same sound).
I did some research and came across forums where people had discovered that the X650 had been shipped with incorrectly configured ESCs for the motors.
The diagnosis and the fix:
My understanding is that the supplied ESCs (Tekko32 F4 45A) were not configured to the right parameters for the supplied motors (MN4014 KV330) - the KV and Pole Count values in the ESC configuration were incorrect in my case. I think this then caused the ESCs to saturate their output past a certain point as a protection against something (don’t know the speicifcs sorry!)
To rectify this, you need to download the ESC configuration software tool. These ESCs run on AM32 firmware and you can download the configuration tool on the linked webpage. I followed the ardupilot documentation to configure the ESCs via passthrough for AM32. This did cause me a couple of headaches due to PWM outputs 1-8 and 9-16 being configured differently with regards to DSHOT, but eventually I managed to reconfigure each of the four ESCs:
I set to 340kV as this was nearest option to the actual motor value, and 24 poles on the motor.
After this configuration, I repeated my ground-based motor test by stepping the command by 10% at a time, and before I even got to 50% everything sounded much faster and more powerful. I took the platform out to try and fly it again and it worked beautifully. It’s flying very well now and I’m working my way through all the normal setup and analysis stages before I begin my experimental side of the project.
I hope this helps you or someone else that is having this problem. It seems like a number of x650s have experienced this issue and I wonder what’s gone on. I will be getting in touch with Holybro about this.
