Constant speed between waypoints (survey grid) not working

Hi everyone!

Been using mission planner for a few works now and its awesome (was a ex dji ground station user lol)!

My only ‘problem’ is that the drone wont keep the speed that i put in the survey grid option (in this case 35km/h = 9.5 m/s), but in the field the drone wont go even close to that speed, was always between 5ms to 7ms.

Already change the value in the WPNAV_SPEED to 10m/s, but the results are the same.

Is there any trick to get the drone fly in a more constant speed? at least near the 9m/s.

Another thing, see attach, the ‘‘use speed for this mission’’ in survey window what it really do?


Thank you!

you need to tick use this speed. otherwise the number is just used to calculate the time estimates.

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Michael Oborne thank you for the fast reply (and congrats on the good work regarding the MPlanner).

Today had another test:

  • Did the survey (grid) with the tick on the speed 6m/s.

  • Did the flight but once again he wont go to the speed i put in the survey grid, was between 4,5ms to 5,6ms.

  • In AltHold i can reach up to 15m/s top speed, but in Loiter (after autotune) the max is 5m/s

Any idea what could be wrong?

The logs and the mission, if anyone can give a quick look, are in here:

edit. telemetry (alot of remote noise) and rc radio going to failsafe because i’m still trying to find the best spot for them in the frame (tarot 650)

Thank you


Pretty simple I think. Your max waypoint nav and loiter speed is set to 500cm/s. I usually set mine to 8m/s. Note that a 6m/s will fluctuate from say 5 to 6, never holding 6 perfectly.

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X1Aero Thanks for the reply.

Well did some new tests today.

Did a auto mission with 7m/s (survey grid) but only between the first two waypoints the drone was closer to 7m/s, in the next waypoints the drone was again between 5,5m/s to 6m/s.

Funny thing is that in the RTL the drone was ALWAYS in 7m/s (400m from the last waypoint to home), the speed that i want it.

What could this be? Some Bug? Some parameter regarding the attack angle?

Gonna attach once again the logs if anyone wanna look at it:


Try to make a test mission with a distance of 100 meters between two waypoints and look at what is the max speed reached , it could be that the settings of your copter do not allows enough accelleration between two waypoints if these are at a short distance.

There could be a number of reasons if it’s not a simple fix like max waypoint speed… I’ve had problems with forward speed when flying large units (28’) props. I would get this pitching in the logs that wasn’t obvious to the eye in flight. Turns out the throttle min needed to be set lower. Basically the front drives weren’t slowing down enough. Check you RC out graph and see is your front motor are clipping at the low end (flattening out),

Can you give a look at the logs?

its too much for me to try to see that, i’m a newbie to understand some numbers @ the logs.


Thank you

Can anyone tell me what are this ‘‘angles’’ and ‘‘grad%’’, in the attch image?

Should be this number in all waypoints?

This is the angle and % slope created by the difference in altitudes at each WP. If the WPs are at the same altitude, then they will be zero.

Ok, my turn for a question.
Does anyone know how to find the commanded speed in the logs? I want to compare commanded speed to actual speed. I have ch.6 set to change speed, and I want to see when I moved the knob.

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anyone can help me? same problem

I already answered on your other thread.

Please do not hijack closed threads. And answer the questions I posted.