Aftermarket prop woes

[Jeffm912]

I can vouch for the quality of the MA props only as I have used their props for over 2 decades on planes and quadcopters. The almighty quietest prop question is subjective to each individual as is hearing. MA is much better quality than oem that is a fact. As for those of us that are getting older, I don't hear my wife jabbering away 4 feet from me and that's the way I prefer it.

Jeff

 

[Starz]

I’m well aware of the the lifespan of the company itself and have not questioned the quality of what they build. Many pilots will not attach anything other than MA props on their aircraft and rightfully so. My opinion of their advertising for the DJI products is apparently not in line with some of the crowd.

 

[Jeffm912]

I’m well aware of the the lifespan of the company itself and have not questioned the quality of what they build. Many pilots will not attach anything other than MA props on their aircraft and rightfully so. My opinion of their advertising for the DJI products is apparently not in line with some of the crowd.

We all can't agree on everything. That would be boring and we would never be better than we were! I concur...

Jeff

 

[Thomas B]

If you want the quietest prop between the two discussed, fly them yourself. Remember that dB is a measure of “sound pressure”, ie, energy. Every 3dB up doubles, while 3dB down halves this energy.... and usually the perceived volume. Remember, however, that volume may not be related to dB ratings, for instance, due to individual hearing loss at certain frequencies.

 

[FoxhallGH]

I’ve looked at the graph(a very well done piece of work that not many would be able to do) and I see a ton of information on rpm. I thought the discussion was addressing the claim being made of low noise and improved flight time. There are many here that believe those claims to be true and that there are reviews to substantiate that possibility. I’m not trying to rock the boat that carries a ton of passengers, and maybe my gray matter is missing something, but I’m not seeing an answer in what is presented in that work. If someone can point out what I’ve missed, please do. Thanks

From a practical point of view - I've found that the lower rpm can have a definite affect on the sound level from the prop's. Lower rpm translates into a slightly lower dB in regard to the 'loudness' of the sound, but more significantly, a lower rpm also gives a lower 'pitch' to the sound - so it's not so much 'swarm-of-bees' but more toward 'flock-of-birds' ... My experience has shown that both the Master Airscrew 'Stealth' prop's, and Carbon-Fibre [C-F] copies of the DJI 8331 'quiet' prop's exhibit this lower rpm and less intrusive noise ... However - there is a big difference between C-F 8331 prop's and Master Airscrew 'Stealth' [MAS] ...
The MAS prop's DO extend the flight duration, where the C-F 8331 prop's don't! Now that means the lower rpm's of the MAS prop's are due to efficiency of the prop' design, where-as the lower rpm's of the C-F prop's are not. The C-F 8331 prop's are very rigid and therefore it's like the Mavic's motors are pushing a barn door though the air. These C-F prop's take more 'energy' to swing, and therefore, are not as efficient as the MAS prop's - and from my tests, not as efficient as the DJI 'quiet' prop's either ...

 

[Gazmg]

This still going on,its good we are getting information , it does give it a slight different noise and it does seem quieter but that maybe the different pitch its giving off rather then db.I have been flying with them for a while and i have know problems with the blades, i check the security of the joints before every flight and have marked them to see if the screws are coming loose which secure the blades in place , no movement there.No weare on the locating lugs neither.I have no problems with gimble shake and have turned the gain down to 96%.

So from my experience i do not have a problem with them,or battery life or temp etc........

 

[old man mavic]

hi fellow flyers there have been many threads on the subject of which props to use on our UAVs,and as i have said before,it is really down to the individual person to decide what they are most happy with,you need to be careful,with none genuine DJI type props,advertised as suitable for your UAV as there can be some questionable build quality with them,but with regards to MAS props they are well made and do impart a different flight envelope to the UAV,because of their different design and material.i myself prefer to use the original props supplied by DJI but that is my choice as the PIC

 

[MavicFT1P]

I can understand pimping everything possible on RC, (anodising, lockwiring every bolt) but theres somethings Mavic just got right imho. Only time i ever had a prop issue was was when i slammed Mavic down so hard the propellor flexed into the arm and a section sheared off.

I didn't even realise until i got back to Landing Pad as Mavic had just compensated RPM's with its unending cleverness.

The carbon Fibre ones suck as y'all know. And the Platinum ones make you tumble in Extreme flying situations *cough*

 

[Antonf]

I'm away at the moment and don't have sophisticated equipment to do the relevant tests, but I'm sure the various phone apps that measure noise levels will give some indication, even if it is only relative. Will do some measurements when I'm back in May

 

[FoxhallGH]

I'm away at the moment and don't have sophisticated equipment to do the relevant tests, but I'm sure the various phone apps that measure noise levels will give some indication, even if it is only relative. Will do some measurements when I'm back in May

This is a good video with some 'sound test' comparisons ...

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[Theo111103]

Weight vs RPM: Characterization and Comparison of MPP driven DJI 8331 propellers vs 3 others

As promised quite a while ago. When taken a close look at the differences it clearly shows where the props would find their applications. The 3blade Carbon props give high-wind alarms for a reason: RPM's are low from front to back of their Characteristics. The material of the cheap chinese...

mavicpilots.com

@FoxhallGH

Were you able to read the post? Just checking!

 

[FoxhallGH]

@FoxhallGH

Were you able to read the post? Just checking!

I was able to thanks Theo ... Very interesting ... Just so I'm sure of what you were doing there - you were hanging some weights under the Mavic and recording rpm? Yes??

 

[Theo111103]

I was able to thanks Theo ... Very interesting ... Just so I'm sure of what you were doing there - you were hanging some weights under the Mavic and recording rpm? Yes??

Basicly yes, i just mounted a lightweight box on top of the mavic to stay close to it's original COG, and put in sets of 4 grams of wheights in order to gradually increase load as you can see in the Exel sheet.

All the other initial base/dat is just combinations of Tares from MPP, the basket, various Batteries and various props... I had to take all that in account io to stay neutral to the final data.

The RPM was recorded by both stroboscope and Remote Control

Front and backside propellors generate different response as a reaction on load. I just took all three of these read-out datapoints and put them in a graph to enable easy comparison.