TAKEOFF mode instantly ramping motors

This is something that has been bugging me for a while: I have never been able to get the motors to ramp up gradually using TAKEOFF mode.

When I use TAKEOFF mode, the motors instantly spool up. When I use Auto mode with a mission that has a TAKEOFF command and then LOITER_UNLIM, the motors ramp up nicely rather than instantly maxing out. I have tried this on multiple versions (4.0.x including latest master).

My parameters for the pertinent ones are:


You can see in the video, I switch my flight mode from auto to takeoff and the result. Does anyone have TAKEOFF mode slowly ramping the motors? This isn’t a big deal for smaller planes but for my Believer, I much prefer the slower ramp-up. Thanks!

Edit: Added example video.

although I’m facing the same problem, described in a post with no answers yet, I can share some findings that I hope could help.

Btw not tested in flight yet, but I found that TKOFF_THR_SLEW didn’t produce any change whatever was the value; the motor started to max rpm instantly. Then I put TKOFF_THR_SLEW=0 and I managed THR_SLEWRATE only, and the behaviour was as expected, the motor progressively reached the value defined in TKOFF_THR_MAX.

So I concluded that this could be a correct way to input Takeoff mode parameters , but I’m still waiting form some confirmation .


Hello thanks for the response. It is my interpretation that this would not be a solution because THR_SLEWRATE would apply to automatic throttle modes. So there could be a situation where the THR_SLEWRATE could be disastrous. I.e. if you are flying with terrain following and the plane needs to climb quickly. THR_SLEWRATE would hamper the planes ability to provide instant, 100% throttle.

This is a good point i didn’t consider.
So the doubt , at least for me, if the parameter TKOFF_THR_SLEW, that should sove the problem, works or not , still remains

we’ve just fixed this, TKOFF_THR_SLEW is now aplied to TAKEOFF mode as well as AUTO takeoff


Thanks @tridge . Looking forward to testing this out.

Thanks tridge,
one more question: quadplanes are mentioned, is it valid for normal planes too ?

@cpinz I tested 4.1.2 on the bench and TKOFF_THR_SLEW is respected and behaves as it should. Thanks again @tridge.

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I confirm too, it works. Thank you all

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