Most efficient speed for max range

CyberNate · Mar 10, 2017

wildpig said:
What i am asking is that it seems like dji is limiting the speed to ground speed rather than limiting the speed by limiting the RPM (pseudo airspeed). at least what I have seen so far in P mode , with or without forward avoidance, the forward speed indicated on the controller seems to be locked at 20 mph with forward avoid and locked at 30 mph without. I am saying this b/c when i fly with a tailwind, my speed on the controller never exceed either 20 or 30 mph. and when i make the reverse trip now with headwind, my speed on the controller now showing a slower speed than either 20 or 30 mph.

I think that dji should really peck the limit to rpm rather than ground speed. It's a real handicap when they do this limit regard to ground speed rather than rpm. This is especially true with wind around, b/c now you are also losing out on the wind assistance on your leg with the tailwind while you get the penalty of the headwind going the other way

I completely understand your point. They have decided on setting software limits against GPS and barometer data. A strong tail wind cannot be utilized as effectively as a result. Anyway, if you check my 8.56 mile flight, you see that the homebound leg was 4.28 miles and only 35% battery used (42% at turn around - 7% at landing). I think it is apparent that the tail wind wind aided the craft quite a bit. This was p mode with obstacle avoidance disabled. The speed is limited to 32mph ground speed. I had around 7 to 10 mph tail wind on return leg. I suppose I could have used sport mode for a bit more ft/watt-hr efficiency, but that's already pretty good.

wildpig · Mar 10, 2017

Sports mode=great way to discharge battery fast. was able to barely get 16 min. did have fairly strong wind today though...

Kestrel · Mar 10, 2017

Not to split hairs but I did 43.78 mph with tail wind in sport mode.

Flylongjohn · Apr 25, 2017

CyberNate said:
View attachment 8107

Made it out 22604ft (4.28 miles) and that was with a strong head wind flying low at 164 ft altitude in the city. I turned around at 42% battery to come back which gives you an idea of the amount of wind I flew into and still at 7% when landing. Completely stock. View attachment 8106

Mavic In route to the house now. I am just so impressed that 125 mw can go that far on 2.4. It just blows my mind . Great work man!! That's what I am looking for to fly mail to the other island lol...

Ebruce · Apr 25, 2017

CyberNate said:
View attachment 8107

Made it out 22604ft (4.28 miles) and that was with a strong head wind flying low at 164 ft altitude in the city. I turned around at 42% battery to come back which gives you an idea of the amount of wind I flew into and still at 7% when landing. Completely stock. View attachment 8106

Wow! That's a helluva flight! Nicely done!

mpa · Apr 25, 2017

use fixed wing mode, this surprisingly added 5 minutes to my normal 18 minute flights from 100% to 30% batteries

skan · Jun 8, 2018

CyberNate said:
The max distance will be covered at the optimal RPM speed of the motors. With no wind, that speed is at around 30mph. You can see the max efficiency RPM/Power in the tachometer by going to sport mode. The RPM/Power line goes around the Radar circle. The point where the green line turns blue is the maximum efficiency point. Keep the speed near that intersection and you'll see a speed of about 30mph when there's no wind. I've gone 44,000 feet without much effort, and that was not even an optimal day. Had a fair amount of cross wind.

Edit: I should add, you can achieve the optimal speed in an easier way as well. Simply turn off the front obstacle avoidance and use P mode. Push the right stick full forward. The Mavic is programmed to go right at about 30 mph, which I believe is no accident. That is for maximum efficiency.

What if we had tweaked the parameters on the firmware?
I mean, 30mph in regular sport mode, but what if we have modified parameters such as max tilt (from 35º to 50º)?

Gryphon962 · Jun 8, 2019

skan said:
What if we had tweaked the parameters on the firmware?
I mean, 30mph in regular sport mode, but what if we have modified parameters such as max tilt (from 35º to 50º)?

Old thread but to answer the above question, DJI will limit the max speed to ensure that users don't continually pull too much power through the ESCs and the motors. I guess they came up with 42mph as the maximum safe continuous speed for flight that wasnt going to result in overheated Mavics that they would have to fix under warranty. Will it go faster? Sure, but you'll have to write your own firmware.