I built a smaller copter (TOW 1290gr) with following specs:
X quad
Kakute H7 v1.3 stack with Tekko AM32 metal 60A
4S Lipo
RCTimer 2212-920kv motors
10x3.8 APC props
M100-5883 GPS/compass module
Graupner GR-12 HoTT as receiver
Problem is: copter does not want to take off. Motor RPM seems to get limited to about 4200 rpm, which is close but not enough to lift off.
See the log file where the copter is being held in the air by a helper while I was advancing throttle slowly to full (in STAB mode). There is not audible rpm increase after half throttle.
I am using 4.7.0-dev
What am I doing wrong here?
Use Dshot600. I guess this craft has flown before from the parameters that look Auto Tuned. What’s different now?
And the throttle output is at 100% so it’s plenty “open” enough.
I have tried Dshot600, same effect. The parameters look auto-tuned because I copied the settings from a similar working copter (same hardware, but different motors and props). This new copter has never flown.
Judging from ecalc this copter configuration has /plenty/ power to take off.
If you look at the motor rpms, they don’t go beyond 4000-something, and that doesn’t look right.
Yes, I know that. Of course I also tested it standing on the ground and trying to takeoff like normal. Same effect. The motor rpms are not increased enough to get sufficient thrust.
Motor current is 1.5 amps (no typo!) while applying full throttle in STAB mode.
I figured it out myself. Problem was the configuration of the Tekko 4in1 ESC. It was set to 2200 kv Motors, while mine are 920. Set that back to 900 (next suitable value) and the machine flies now.