Mavic Pro Motor Mod

chazz · Jun 2, 2018

beanbubba said:
Well, these appear to be reverse threaded props and self tighten during flight. It appears that the mavic shuts the motors down hard and fast and the forward momentum is enough to unscrew them all the way when the motors stop???

EDIT: I twisted the props a tiny bit tighter on the next flight and this did not happen again.

I'm happy you figured it out! your lucky they didn't fly off while braking during flight if they were that loose. If i was going to explain how tight the props should be i would say as tight as you would the plastic cap on a soda bottle.

chazz · Jun 2, 2018

Were you able to go full sport speed without an issue? No weird vibrations in any of the motors?
I agree with taking your time and i'd only add one carry-on at a time until you hit the max weight you feel comfortable with. My P3 all decked out weighs 2300grams but that's really pushing it and with a 4s lipo... I'm exited to see your experience with this and have my fingers crossed for you and hope you have no more unsolvable issues...It looks like you and I are the only ones attempting this mode so please keep me posted every step of the way...

Edit: You should check your flight logs or at least airdata after every jump in added weight to keep an eye on your current.

chazz · Jun 2, 2018

Something i forgot to ask is whats the weight of your bird with all the mods and stock battery?

beanbubba · Jun 2, 2018

chazz said:
Something i forgot to ask is whats the weight of your bird with all the mods and stock battery?

beanbubba · Jun 2, 2018

chazz said:
Something i forgot to ask is whats the weight of your bird with all the mods and stock battery?

I am going to work up to 3x MS5200. They weigh 343g each.

That would make AUW right at 1951g.

beanbubba · Jun 2, 2018

milchoni said:
I’ve just bought 4 motrs and I was about to install them on my Platinum today when I red this post. Maybe it’s a fw issue because chazz’s connecion order Is the same. I am very concerned and I will watch this thread very carefully.

Milchoni, did you ever build yours?

beanbubba · Jun 2, 2018

Just did a max hover time test on the stock battery.

Battery had 17 charges and never run low or abused. It was windy - average 8mph.

Jun 2, 2018 12:09PM | General / Overview | Drone Flight Log from DJI GO app, version 4.2.14 on iOS | Total Mileage: 408 ft | United States | Airdata UAV

beanbubba · Jun 2, 2018

I have never heard a p3 before and don't have a reference point to know if these motors sound ok.

Please watch this and turn the volume up and let me know your thoughts.

I am also reprinting the rear-left arm, it is a degree out of alignment...

lolo780 · Jun 2, 2018

Plot the hover watts per gram thrust at each weight to see how the efficiency curve is.

Is your motor wattage around 105W right now?

beanbubba · Jun 2, 2018

lolo780 said:
Plot the hover watts per gram thrust at each weight to see how the efficiency curve is.

Is your motor wattage around 105W right now?

Lolo, you have to remember that not all of us are electrical engineers. I just play one on TV

beanbubba · Jun 2, 2018

beanbubba said:
Just did a max hover time test on the stock battery.

Battery had 17 charges and never run low or abused. It was windy - average 8mph.

Jun 2, 2018 12:09PM | General / Overview | Drone Flight Log from DJI GO app, version 4.2.14 on iOS | Total Mileage: 408 ft | United States | Airdata UAV

It's been so long since I tested without external batteries. How long will a factory bird hover in these same conditions?

lolo780 · Jun 2, 2018

beanbubba said:
Lolo, you have to remember that not all of us are electrical engineers. I just play one on TV

Csview has a parameter motor watts avg all. Note down air density to make your data comparable.

Hover time on a stock pro with platinum props about 28 min with 103x barometer.

chazz · Jun 2, 2018

Yeah i think is Plucked. Here's a pic of my mess. Now I'm noticing it happens on the front right motor before the left. and now its making me want to continue changing motors! I haven't seen that before. This is with 2 5200's and a 4000 and the stock battery weighing 1980grms or close to that...

Here's a link to the flight data of just a few seconds at the time of the attempted liftoff.

FLY528.DAT

milchoni · Jun 2, 2018

Finished! Actually I am the 3rd guy with this mod..

lolo780 · Jun 2, 2018

chazz said:
Yeah i think is Plucked. Here's a pic of my mess. Now I'm noticing it happens on the front right motor before the left. and now its making me want to continue changing motors! I haven't seen that before. This is with 2 5200's and a 4000 and the stock battery weighing 1980grms or close to that...

Here's a link to the flight data of just a few seconds at the time of the attempted liftoff.

FLY528.DAT

View attachment 39299

Does it fly differently if you subtract one battery pack?

beanbubba · Jun 2, 2018

milchoni said:
Finished! Actually I am the 3rd guy with this mod..

Please send close up's of your motor mounting adapter.

Did you re-use the factory motor wiring?

Send close up with all the prop's attached and how close they come to the body of the bird.

Why did you choose gen1 motors over gen2 motors?

Thanks!

beanbubba · Jun 2, 2018

This is my morning flight test.

I have to wait for the power connector epoxy to dry over night first

beanbubba · Jun 3, 2018

Well, my epoxy hardened enough for a test flight tonight. This mod may not be ready for prime time. I did a hover test with dual MS4000 plus factory battery and at approximately 27 minutes into the flight, the bird started an uncontrollable spin. I was at the controls the entire time and when this happened I did left stick down until it landed.

The entire flight I received current error and max motor speed errors non stop. This is beyond my skill set and need guidance from the experts if I am to proceed.

Jun 2, 2018 10:55PM | General / Overview | Drone Flight Log from DJI GO app, version 4.2.14 on iOS | Total Mileage: 328 ft | United States | Airdata UAV

lolo780 · Jun 3, 2018

Max motor speed means 100% PWM. If you're on 3s then it's understandable since this motor and prop combo is designed for 4s @ 1300ish grams.

Motor current errors are probably from the flight control seeing load way above what it expects.

The important thing is keeping ESC temps down.

beanbubba · Jun 3, 2018

lolo780 said:
Max motor speed means 100% PWM. If you're on 3s then it's understandable since this motor and prop combo is designed for 4s @ 1300ish grams.

Motor current errors are probably from the flight control seeing load way above what it expects.

The important thing is keeping ESC temps down.

OK, tell me what batteries to buy from where and I will try it.