Mavic Pro Propeller Comparison. 5 brands

[51 Drones]

Just ran a day of testing. Thought you guys may find some interest.

 

[Wilbur]

Just ran a day of testing. Thought you guys may find some interest.

I enjoyed your analysis. I have used stock mp props and MA props. I was switching back and forth, but now I fly with the MA. Your right about the build quality. I found one to be quite stiff, but it has loosened up due to many flights. I recently flew from treasure island to Alcatraz and back using the MA. Not one issue. I like them.

 

[FoxhallGH]

Just ran a day of testing. Thought you guys may find some interest.

Thanks Russ - great video as always ... I've just noted that [must have opened up very recently], we now have a European distributor selling Master Airscrew prop's for Mavic Pro off of Amazon.co.uk ... Yay!! - I've just ordered a set for Christmas! I've already been branded a heretic on this Forum for championing carbon-fibre prop's - so looking forward to going the whole hog with the MA set for my MP Platinum.

 

[WithTheBirds]

these results must be wrong- the CF props should have been more “locked in”, “crispier” and have more “rock solid” hovering.....Atvkeast based on other user accounts in the forums.

Thank you for doing this.

 

[GavieboyDji]

Just ran a day of testing. Thought you guys may find some interest.

You cant beat the Sound the DJI standard prop make when itys flying they sound brilliant I use the Stock and switch with the low noise dji ones when I want to be sneaky and make less noise, but the sound the stock makes gives the mavic a beefy sound when speeding about bit like a jet. hahahahaha

 

[FoxhallGH]

these results must be wrong- the CF props should have been more “locked in”, “crispier” and have more “rock solid” hovering.....Atvkeast based on other user accounts in the forums.

Thank you for doing this.

I use CF prop's pretty much exactly like the ones Russ used for the tests. His tests didn't talk about the stability of the drone - but I have noted that CF prop's do make my MP Platinum drone more stable in the hover. Tests I have done, did confirm that flight duration is shorter using the CF prop's ... Motor rpm's are lower with CF, which means the motors are working harder. The CF blades are much stiffer and therefore maintain their pitch as they spin through the air, making them more responsive - but the cost is higher current drain from the battery.

 

[kidroc]

I'm i love with MA props for the mavic all i use now they are quieter and just feel better to me..

 

[mlwdis]

Just ran a day of testing. Thought you guys may find some interest.

Thank you for doing the tests and taking the time to share valuable information. By the way. Merry Christmas and a Happy New Year.

 

[Tbredhed]

I use CF prop's pretty much exactly like the ones Russ used for the tests. His tests didn't talk about the stability of the drone - but I have noted that DF prop's do make my MP Platinum drone more stable in the hover. Tests I have done, did confirm that flight duration is shorter using the CF prop's ... Motor rpm's are lower with CF, which means the motors are working harder. The CF blades are much stiffer and therefore maintain their pitch as they spin through the air, making them more responsive - but the cost is higher current drain from the battery.

But if you noticed the Master Airscrew had even lower rpm and had the longest hover time.
Cheers

 

[slkfis]

I prefer the Master Air Screw.

 

[FoxhallGH]

But if you noticed the Master Airscrew had even lower rpm and had the longest hover time.
Cheers

I did notice that - and I'm pleased to find out that we now have a European distributor selling MA prop's on Amazon.co.uk. - YAY! - My order is in and I'm eagerly awaiting delivery.
I'm chewing that test result over, because I can't put logic to that result. If the rpm is lower, then the motor has to be working harder to move the same amount of air ... If you are drawing more current, then how can you get better flight duration???
I did some tests that revealed that flight duration results can really be affected by the battery you are running the Mavic with to do the test. My conclusion was that unless you use the same battery for each prop-set, and have the same weather conditions, the result has to be taken as an approximate rather than an absolute ...

 

[Wilbur]

I did notice that - and I'm pleased to find out that we now have a European distributor selling MA prop's on Amazon.co.uk. - YAY! - My order is in and I'm eagerly awaiting delivery.
I'm chewing that test result over, because I can't put logic to that result. If the rpm is lower, then the motor has to be working harder to move the same amount of air ... If you are drawing more current, then how can you get better flight duration???
I did some tests that revealed that flight duration results can really be affected by the battery you are running the Mavic with to do the test. My conclusion was that unless you use the same battery for each prop-set, and have the same weather conditions, the result has to be taken as an approximate rather than an absolute ...

Keep an eye on the rivet joints. They can come a bit stiff. One so much I wouldn't trust the cyntrifigal force to open it. Personally, its a habit of mine to open them up pre-flight.

 

[clovis09]

Just ran a day of testing. Thought you guys may find some interest.

Thanks Russ. Like ALL your vids it was a good watch.

 

[WithTheBirds]

I use CF prop's pretty much exactly like the ones Russ used for the tests. His tests didn't talk about the stability of the drone - but I have noted that DF prop's do make my MP Platinum drone more stable in the hover. Tests I have done, did confirm that flight duration is shorter using the CF prop's ... Motor rpm's are lower with CF, which means the motors are working harder. The CF blades are much stiffer and therefore maintain their pitch as they spin through the air, making them more responsive - but the cost is higher current drain from the battery.

Of greater consequence than current drain on the battery (unlikely to be an issue given it is still operating well within its C rating) is increased dissipation (I2R losses) from the on resistance of the ESC inverter mosfets.

The reduction in efficiency is expected- your claim of increased responsiveness is unlikely. In fact to the extent you might obtain increased responsiveness would reveal that the original design of the propulsion system was defective. It is reasonable to expect that in engineering the propulsion system motor KV, and in particular the combined motor/speed controller efficiency characteristics would have been carefully matched to the propellor. Increased thrust/RPM wont just provide reduced efficiency, it will also reduce responsiveness as the propulsion system can’t respond to throttle inputs as quickly.

 

[crlmjohnson]

I like the stock blades.

 

[FoxhallGH]

Of greater consequence than current drain on the battery (unlikely to be an issue given it is still operating well within its C rating) is increased dissipation (I2R losses) from the on resistance of the ESC inverter mosfets.

The reduction in efficiency is expected- your claim of increased responsiveness is unlikely. In fact to the extent you might obtain increased responsiveness would reveal that the original design of the propulsion system was defective. It is reasonable to expect that in engineering the propulsion system motor KV, and in particular the combined motor/speed controller efficiency characteristics would have been carefully matched to the propellor. Increased thrust/RPM wont just provide reduced efficiency, it will also reduce responsiveness as the propulsion system can’t respond to throttle inputs as quickly.

You'd think so ... But the improved responsiveness is 'observed' not 'imagined'. The stock prop's are very flexible in both longitudinal and torsional directions. This means that the prop' can help to 'absorb' some movement of the Drone due to turbulence - and should make it a more stable camera platform. But the trade-off is that due to the prop's absorbing some of the movement, they also make the Drone slightly slower to respond to control input. I'm not saying that this has a 'huge' effect, but it is there to see.

The Mavic relies on motor rpm to manoeuvre. If a motor spins faster, then the immediate effect on a stock prop' is to flex and reduce the pitch angle - especially near the tips. This is due to inertia and air-pressure and is momentary and helps absorb the 'shock' of the rpm change. The stiffer CF prop' blades don't do that flex, and therefore the transferred movement is more 'instant' with the load being absorbed by the motor, rather than the prop'.

In regards to the MOSFET's - the Power loss in a MOSFET is low, as it is a semiconductor that's most like the old thermionic valves (that's why they are so good for sound Amp' equipment). The more you turn them on, the more like a short circuit they become. I'd expect to feel heat in the motors and Drone body if the electronics were working harder - but tests with both stock and CF prop's end up with the drone feeling the same amount of warm for both (but hard to measure, because the Mavic has a cooling fan). Yes we are talking about the motors working harder, but we are only observing a 2 to 3 minute reduction in flight duration (about 10%), so not very much harder ... It would be interesting to see if the amount of work that the ESC has to do 'reduces' with the CF prop's as the control inputs may be less to get the same effect [??].

When you work with a fixed-pitch propeller as is used on the Mavic, you have to remember that the prop' is going to show an efficiency graph that looks like a cross-section of a hill-top. It's a compromise designed to give a wide range performance covering all flight characteristics - but at some point it's going to be better than others. It's no surprise that a different kind of prop' can show better characteristics in different parts of the flight envelope - and also no surprise that some parts would be worse! The interesting thing for me is that there have been comments about how CF prop's can be better for; filming wildlife (quieter), for subjects where you need to be very stable (close-up inspections), and when it's very cold (stock prop's become brittle) ... They may not be an all-round solution, but they are a tool in the box for specific applications.

 

[BossBob]

I did notice that - and I'm pleased to find out that we now have a European distributor selling MA prop's on Amazon.co.uk. - YAY! - My order is in and I'm eagerly awaiting delivery.

Delivery early/mid January? Bulgaria! I know we’re buying via Amazon but I’ll fly what I’ve got for now thanks. Parts from China have arrived quicker.

 

[FoxhallGH]

Delivery early/mid January? Bulgaria! I know we’re buying via Amazon but I’ll fly what I’ve got for now thanks. Parts from China have arrived quicker.

LOL - yes - I have a note from Amazon saying that their donkey should have the package with me between the 3rd & 15th Jan (via Bulgarian Post) ... Fortunately, I'm not needing these to fly ...

 

[kidroc]

But if you noticed the Master Airscrew had even lower rpm and had the longest hover time.
Cheers

I noticed the low rpms too.

 

[WithTheBirds]

You'd think so ... But the improved responsiveness is 'observed' not 'imagined'. The stock prop's are very flexible in both longitudinal and torsional directions. This means that the prop' can help to 'absorb' some movement of the Drone due to turbulence - and should make it a more stable camera platform. But the trade-off is that due to the prop's absorbing some of the movement, they also make the Drone slightly slower to respond to control input. I'm not saying that this has a 'huge' effect, but it is there to see.

The Mavic relies on motor rpm to manoeuvre. If a motor spins faster, then the immediate effect on a stock prop' is to flex and reduce the pitch angle - especially near the tips. This is due to inertia and air-pressure and is momentary and helps absorb the 'shock' of the rpm change. The stiffer CF prop' blades don't do that flex, and therefore the transferred movement is more 'instant' with the load being absorbed by the motor, rather than the prop'.

In regards to the MOSFET's - the Power loss in a MOSFET is low, as it is a semiconductor that's most like the old thermionic valves (that's why they are so good for sound Amp' equipment). The more you turn them on, the more like a short circuit they become. I'd expect to feel heat in the motors and Drone body if the electronics were working harder - but tests with both stock and CF prop's end up with the drone feeling the same amount of warm for both (but hard to measure, because the Mavic has a cooling fan). Yes we are talking about the motors working harder, but we are only observing a 2 to 3 minute reduction in flight duration (about 10%), so not very much harder ... It would be interesting to see if the amount of work that the ESC has to do 'reduces' with the CF prop's as the control inputs may be less to get the same effect [??].

When you work with a fixed-pitch propeller as is used on the Mavic, you have to remember that the prop' is going to show an efficiency graph that looks like a cross-section of a hill-top. It's a compromise designed to give a wide range performance covering all flight characteristics - but at some point it's going to be better than others. It's no surprise that a different kind of prop' can show better characteristics in different parts of the flight envelope - and also no surprise that some parts would be worse! The interesting thing for me is that there have been comments about how CF prop's can be better for; filming wildlife (quieter), for subjects where you need to be very stable (close-up inspections), and when it's very cold (stock prop's become brittle) ... They may not be an all-round solution, but they are a tool in the box for specific applications.

Can you be confident your observations aren't skewed by your expectations?? Absent actual measurements the reliance on observation is questionable particularly given that any improvement would be subtle at best.

In any case supposing your claim of increased responsiveness might proved true what advantage does it provide? Does the benefit justify a 10% reduction in efficiency?

If we consider other attributes you claim as favouring their use they aren't quieter, there is no evidence of increased stability (this is unlikely given higher thrust/rpm = higher motor torque loading with reduced ability of the propulsion system to respond as quickly to commanded speed changes resulting in delayed response and less precision in applying small adjustments to thrust). The increased brittleness at low temps consideration is probably irrelevant and to the extent it might come into play would likely favour the stock props. Nylon performs very well at low temps (certainly those within the range the Mavic could be flown) however we don't know what aftermarket props are composed of, particularly the FAUX CF ones.

MOSFETS could be said to be like a tube to the extent they are voltage drive and applied to a linear amplifier the circuit topology and operation is similar in many respects. That is where the similarity ends and it can't be said they might be preferable to bipolar transistors in audio although they often are but that is principally due to the overall design and circuit complexity. The fact remains, all MOSFETS regardless of efficiency experience conduction losses which generate waste heat proportionate to the current delivered to the load. Lower motor RPM for a given thrust = higher current, an inescapable fact and the observation I was making. I did not suggest you should expect ESC failure however higher operating temperature is a given with reduced reliability and efficiency.

Any consideration of efficiency and performance needs to be applied to the whole propulsion system, not just the rotors. What happens when you fit a wheel tyre combination to a vehicle with a larger rolling diameter? Your engine runs slower for a given speed, no question. Do you save fuel? Not usually.... What happens when you are climbing a steep grade? You often need to change down a gear as you are now operating outside the design parameters of the engine and driveline. The vehicle definitely won't be more responsive, this comes from operating the motor over a wider RPM range and at higher revs generally where more output power is available.