From my understanding you want to leave some head room for the governor. Have heard 92% is a sweet spot. Whether this is true or not, either way one wouldn't want to run the ESC or governor at 100%, correct?

Also understand it is best to run the rpm more according to the gearing and math rather than running the ESC at too high or low of a TC percentage to drastically change the head speed. This would be better suited with a gearing and/or motor swap, correct?

As too low of a TC percentage makes the ESC work harder. Resulting in more heat, maybe excessive, which may result in shorting the life and possibly reliability of the ESC, correct?

So....Using the Spirit Governor they ask to set the Max head speed and then extrapolate from there.
So would I want to enter the true calculated max head speed of say @ 2295. Then set my TC at 92%. Which would mean I am flying the heli at 2111 rpm. Or would it be better to set the Max head speed within the Spirit to say 2495. Then with my TC at 92% the flying head speed is at the recommended max @ 2295 rpm?

What would be the recommended safe range for the lowest and highest percent settings for my 3 idle up flight modes? Probably opening up Pandora's box with this question.

Maybe some other skol of thought I am not in tune with?
Any and all help, and advice from the more experienced is greatly appreciated!!!

Just my thoughts, so wait for official answer in case I'm wrong: The thing that really matters here is the duty cycle of the ESC. The Spirit governor will use a pid control loop to output the throttle signal that maintains the requested headspeed, therefore input throttle percent and max rpm set in the Spirit shouldn't matter for governor headroom as long as the throttle output doesn't reach 100%, because as I understand it it only sets the target rpm. Whether Spirit interprets 90% or 60% throttle from the receiver as 2000rpm, as far as I know the output signal to the ESC should do the same thing. It only needs to see at least 50% throttle to engage the governor.

You should however use a headspeed calculator to make sure the output throttle (what the ESC sees) at your desired headspeed is in the ideal range for the ESC. Most want 60-90%, ideally 70-90%, the lower you go the hotter it will get. Google simple headspeed calculator, it has been quite accurate for me at estimating esc throttle% using 95% motor efficiency. You should choose motor and pinion to stay in this range. You can check at both full cell voltage and the lowest you'll be flying it to see if it stays within the range for the full flight.

Thank you very much for the reply and explanation.
I did plug all info into a head speed calculator. The only variable I was unable to find was the motor efficiency. You use 95%, I used the default of 90%. None the less, don't think this is pertinent to my question.
Also can not find anything about duty cycle for the ESC.

I am still unclear.

So I can set the calculated max head speed within the Spirit as is. Then set my TC in my Tx to 100% to fly at max head speed??

During hard manoeuvres, combined with my poor collective management, wouldn't the Spirit Gov be sending 100% to the ESC to maintain the desired head speed??

100% throttle input to the Spirit does not mean it is sending 100% to the ESC. What the ESC needs to get the desired headspeed depends on your motor and gearing. That's what the Spirit governor is doing, it constantly adjusts the output throttle to keep the headspeed where you want it with pid control and probably some built in precompensations. The throttle input signal to the Spirit is reinterpreted as desired headspeed. Sending 100% to the ESC would mean it would spin at the absolute physical limit of your model, which isn't the same and obviously undesirable.

Nonetheless I would not recommend flying at 100% throttle because there could be some limit built into the governor for safety. You'd need someone from Spirit to answer that. The manual for Spirit governor uses 70-90% as an example, so I would just use that.

kv motor x battery voltage

main rotor / pinion

1 result / 2 result

example
1600kv x 25,20 (4.20v * 6= 25,20 at 100% battery)
162/13
40320/12.46
3235 rpm at 100% motor (with 4.20 battery cells)
3081 rpm with 4v battery cells
2927 rpm with 3.80v battery cells

if you have to use governor never exceed 80% engine why the governor he needs of that 20% to boost the engine if there is an effort.
The rpm to set in normal mode and idle 1 and idle 2 It depends on the model of helicopter you use and the size of the helicopter
PS
these values there at 100% thrtottle motor

Thanks for the input.

1 heli is a Trex 550E
Battery 6S 5000mah
Mains 550
Tail 93
Align motor 1220kv
HW ESC 120a V4
Pinion 16
Main gear 170
FBL Spirit GT
22.2X1220X0.90×(16/170)=
Max head speed of 2295 rpm

2nd is a Trex 550X
Battery 6S 5000mah
Mains 560
Tails 96
Align motor 960kv
Align ESC 100a
Pinion 16
Main gear 112
FBL Spirit GT
22.2X960X.0.90X(16/112)=
Max head speed of 2740 rpm

Hope I got my math right there.

Number of cells x Nominal voltage x motor kv x efficiency x (pinion / main gear)

The head speed calculators I have seen all seem to use LiPo Nominal voltage of 3.7 and default efficiency of 90%. Can not find any documentation that references the motor efficiency of either model, so just used the default of 90%

Manual for the HW 120a V4 states to use 85% Throttle but think they are referencing when setting the RPM when using the ESC Governor.
Copy and paste from Manual....
About RPM Standardization & Others
II. For ensuring the speed-governing effect, we recommend setting the throttle amount to 85% or below in both speed-governing modes (Helicopter (Store Governor) & Helicopter (Elf Governor)), so there will be
sufficient compensating room to maintain the consistency of the RPM. We recommend replacing the motor or adjusting the gear ratio if the expected RPM still cannot be reached when the throttle amount exceeds
85%.


Forgive me for being slow but none of this clears up my question.

Do I set the calculated max head speed, whatever that maybe, within the Spirit? Then fly with my Throttle at 85%. So in essence am now flying at 85% of the calculated head speed.
Or do I adjust the rpm to compensate. So the value entered into Spirit is much higher but with throttle set at 85% the resulting rpm is at the calculated max head speed?

Should add I don't use a "normal" mode.
All my flight modes have throttle curves that are flat line

Calculating at 3.7v per cell ensures you can maintain target headspeed for the entire flight (most don't fly their packs lower than that).

You want the governed rpm to be lower than the calculated max. If the esc/motor is operating at its physical limit, governor will not work well. It draws more current under stronger load so you need the headroom.

Motor efficiency is something you can find out by just running it without governor and comparing rpm telemetry to what the calculator puts out. Efficiency might vary based on the load (your flying style) so you'll never get this exact and it's not worth worrying about.

So yes, if you just set the max rpm in the Spirit to the calculated maximum (at 3.7v) and then fly at 60-90% throttle, that ensures you are within the capabilities of the model and governor can work well. If you go any higher (whether throttle, max rpm, calculated voltage) you risk that the governor can't maintain the headspeed because it's already telling the esc to go at 100%.

That's what I was looking for and makes sense.
Thank you Mona!!

Unless someone from the Spirit team jumps in with different advise, I will go with this.

Thanks again
Cheers

I don't know if you know
but if you go in GENERAL- GOVERNOR
and put the throttle curve at 60% the software spirit it tells you the rpm (or any percentage above 50)
PS
obviously you must have set pinion ecc in the software
but be careful that the engine starts unless you use two batteries but if you use 1a battery the engine start

Thanks for the tip.

Yes I do have all the settings programmed into the Spirit and get RPM read out straight to my Tx (NX10) in real time.