0% Throttle not shutting off motor

[miroker]

I am using 2 DSM2 satellites to control unit mounted in my stock Align TRex600ESP. Disconnected all wiring from original working Spectrum receiver and plugged into Spirit following correct wiring diagram. Setup of Spirit went well, especially after getting support from LHS that sold me the unit. On diagnostic page, all channels operate properly and travel limits needed to be set in transmitter for all channels to give -100% to 100% except for throttle. Not sure if I would adjust the limits for throttle regardless. When I spool up to test, everything works as it should, but when I put throttle at off (bottom of travel), the motor does not stop turning. It keeps blades spinning at low RPM until I get brave enough to reach the head button and press. This is not the case when using the Spectrum receiver setup which I reconnected to test throttle shutoff. Any suggestions?

Regards,
miroker

[ZeXx86]

Hello,

it is necessary to recalibrate your ESC (min. and max. throttle values), because there are different throttle ranges between receiver and the unit.
Alternatively it can be fixed with subtrim of the throttle channel in your transmitter.

[miroker]

No recalibration instructions for ESC but by changing throttle end point, was able to get it to stop. Not sure I like that an electronic control does not shut off when off signal is present. According to curves in transmitter, low stick is 0, so why the Spirit unit continues to send on signal is beyond me.

[ZeXx86]

Hello,

it is very normal behavior, in reality it does not matter what % do you see, but what ESC thinks that is low and high position.

So you can either configure it in the opposite way, that you can set 50% throttle and motor will still be off (just by changing your subtrim value for Throttle channel or wrong recalibration).

What is your ESC? I can try to find recalibration instructions.

[MarkT]

Not sure I like that an electronic control does not shut off when off signal is present. According to curves in transmitter, low stick is 0, so why the Spirit unit continues to send on signal is beyond me.

There is no such thing as 'off' in regards to the throttle setting and setting the stick to '0' still has to send a signal, it doesn't turn anything 'off'. The pulse the Transmitter sends is typically between 1 to 2 Milliseconds, with 1.5 usually indicating the middle of the range. So in your case, '0' throttle might mean it is sending a pulse of say 1.1 Milliseconds and if your ESC has been previously calibrated to expect 1.05 Milliseconds as 'off' then it is going to stay slight on until it sees that.

This is why we calibrate the ESC so it learns what we consider to be zero throttle and max throttle.

There are no absolute values for either 'off' or 'full throttle' only what we teach the ESC during calibration. So when you change things that affect the signal sent to the ESC you do need to recalibrate it.

[miroker]

I do not recall ever having to "calibrate" an ESC with transmitter and multiple receivers I use. In the diagnostics page, throttle was showing at -1% prior to changing the end point, so what that was all about I have no clue. I suspect there is a small error in the Spirit somehow as I was having zero issues before installing it.

[ZeXx86]

It is not really error. You didn't recalibrate ESC, because it wasn't needed. When you switching for example between Spektrum and Futaba or other brand, you have to recalibrace ESC. When you switching just different models from same manufacturer, it is mostly very same, so it is not needed to change anything.

But Spirit and any other FBL is behaving as very different "receiver".

This is reason why every ESC has to be calibrated first, before used. Sometimes you have just luck that it is not needed, because preset range was e.g. preconfigured for same brand as you are using. If recalibration is not needed, then this feature is not in ESCs.