Proper RPM scale?

[hyonlim]

Hi.
I'm trying to fly quad with RPM controller.
Below is my setting parameters.

#define DEFAULT_PWM_MIN_VALUE 990 // minimum to consider pulse a valid signal
#define DEFAULT_PWM_LO_VALUE 1020 // lowest running value
#define DEFAULT_PWM_HI_VALUE 2000 // highest running value
#define DEFAULT_PWM_MAX_VALUE 2020 // maximum to consider pulse a valid signal
#define DEFAULT_PWM_MIN_START 1045 // minimum value required to start
#define DEFAULT_PWM_RPM_SCALE 6500 // RPM equivalent of maximum PWM IN in CLOSED_LOOP mode

I think these parameters is not proper. Because, it is very hard to control BLDC motor with several hundred RPM.
If I have lower throttle, like 1070, then calculation will be

(1070 - 1020)/(2000-1020) * 6500 = 331.6327.

So the quad's propeller sounds like fluctuating.

Does anyone flew quad with RPM controller? If so, could you please let me know your settings?

[Yups]

I am using the ESC32 in ClosedLoop - Thrust mode. RPM_SCALE is set to 6000.
Everything works perfect.

I think you got it wrong. RPM_SCALE ist not a factor, it is the maximum RPM of the motor when PWM is HI (2000).

In your case it should be like:
PWM @ 1020 -> RPM = 0 rounds per minute
PWM @ 2000 -> RPM = 6500 rounds per minute

You will get your maximum RPM during the RPM2Voltage calibration.

Hope it helped.

[monkey1]

my rpm2voltage cabli. maxium rpm is 8058. i m using 8038props, do i use 6000 for rpm scale? is it different size props using different rpm scale?

[joebar.rc]

[r0sewhite]

If I ran my calibrations up to 24A but want to limit current to 20A to be on the safe side:

- should I use the max rpm from 24A R2V or from a 20A run?
- should I use the FFxTERM and CLxTERM values from either 20A or 24A calibration?

It seems to make more sense to use all values from the 20A calibrations, can anyone confirm that?

[bn999]

You are best off if you use the lowest current limit possible for your anticipated load requirements.

[r0sewhite]

In this case the 18A calibration gives the best results. What about 20 and 220A? Should I prefer the 22A calibration values because of the high CL3TERM of the 20A calibration? Limiting current to 18A would make me lose too much thrust since I built this copter for some heavy load tests.

18A:


20A:


22A: