Rotor Speed Control - Which RSC Mode is BEST?

This is my first Trad. Heli set up. Help needed in deciding which of the Rotor Speed Control Modes is best for my Trad. Heli situation. I can see pros and cons to all…but don’t have enough experience to choose. Modes: 1) RC Pass Thru, 2) RSC SetPoint 3) Throttle Curve 4) Governor.

Can someone shed light for me on which option is best? Additional info:
-450 sized, 3s electric Trad. Heli with older 60 Amp. Castle Creations ESC (capable of governor speed control)

-Want to be able to manually land and take off - can’t stand the idea of the heli doing an out of control chicken dance on take off. Will consider autonomous later.

-Ideally…would like to keep the throttle at ~70% but would like to have the option to bump it up to ~85% if the winds dictate making a higher head speed desirable. Understand that “less than max throttle” may heat up the ESC, but with lots of amperage overhead in my ESC, don’t think this is a worry.

-Don’t have plans to do 3D or Waypoints during early stages of learning PixRacer n ArduCopter.

-Don’t think I can find a compact enough Head Speed RPM sensor nor space on my bird…so guessing Mode 4 can’t be considered.

-I’m OK with letting my Motor Interlock switch (instead of throttle stick) be the manner to engage and disengage the Rotor Blade spool up and shut down.

Don’t even know the right questions to ask because of my inexperience with PixRacer & ArduCopter. Viewed the great YouTube videos on this subject

…still confused.
Thanks for all help in advance.

Since your ESC has a governor, then you will want to use mode 2.


also check out this post. I described how to adjust the ardupilot parameters to support an ESC with a governor.

Hopefully this will help.
You won’t be able to change head speed while fly unless you change the setpoint which can only be done thru the ground station. Your heli should be tuned well enough that you shouldn’t be required to change head speed while flying whether low or high winds.

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Very helpful advice! I will study the Talon Governor Mode set up thread you pointed out.
As far as head speed, my thinking was a low head speed (70%) would likely result in a longer flight time - wouldn’t it?

Question 1) - If I set the ESC’s spool up speed as ‘very slow’ in the Castle Creation ESC control software, will that cause conflicts with the “ramp_up_time &/or run_up_time” parameters in Q Ground Control? How would you advise to set and balance those potentially conflicting settings? Thank you. Yes, I tend to overthink things.

Question 2) IF I used Mode 1 WITH the Castle Creation’s governor (not inside radio throttle curve) - it seems that functionally Mode 1 would be identical to Mode 2, right? According to Chris Olsen’s video, it appears that I could use the transmitter’s flight mode switch to choose between 3 different RPMs. Did I get that right? AND . . .
If I did want 3 RPMs, I would set H_RSC_SETPOINT to the value of the highest of my 3 available speed. For example H_RSC_SETPOINT=850 if my highest of the 3 governor speeds were 85% throttle. Did I get that right?

Thanks again.

@ MikeM

I successfully setup my 450 heli with castle talon 35 esc with help of bill.I setup H_RSC_RAMP_TIME to 1 sec and set the castle ESC’s spool up to medium and it works great.It spools up nice and slowly.

Regarding 3 headspeeds, i just selected same head speed for all 3 places in the castle setup software.

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Bill - I’m going with your advice and use RSC Mode 2 for simplicity. For the sake of academic discussion please comment on video:
I understood Chris to have said (at time marks 9:18 thru 9:48) that its OK to use RSC Mode 1 (Ch8 input) IF YOU HAVE AN ELECTRIC GOVERNOR on the heli, but NOT recommended if you were using a Throttle Curve in the Transmitter (on RSC Mode 1 set up). The reason I have a sweet sentiment for Mode 1 is the ability to change head speed during flight. Also, just for looks, its cool to have the head spun up to a low head speed while awaiting take off…kind of like scale flying. Thoughts?

Thank you.

The safer way to do what you are asking without using mode 1 would be to use the esc governor with more 3 (throttle curve). The only reason you are using the throttle curve is so you can change the esc Governor speed with the collective position. So you would set the % throttle Output for the lower rotor speed at the 0 % throttle curve point and then the one for the higher rotor speed for the rest of the throttle curve points. Again you would still set the esc in governor mode and have the lower rotor speed for let’s say the 1st governor setting and the higher rotor speed for the other setting. The throttle curve just gives you a way to move from one to the other rather than only using one with mode 2 (serpoint).