Props noise levels

[Soledamcer]

M2P props, am I imagining it, or do they get louder as they get older? How many hours should these last?

 

[Rattydude77]

Many say 200 flights

 

[TheWolfen]

I have not noticed this at all. This kind of thing really would take actual measurements to determine, as it is almost impossible to be objective enough to evaluate it from day to day under varying conditions.

If you suspect they are getting louder buy a new set, find a quiet, open place with no wind and measure the decibels at specific distances while hovering with the old set, then repeat with the new set immediately. I honestly don't know why the sound would change barring any damage, but check it out!

 

[johnmeyer]

I have one of the old Radio Shack sound meters that lots of people (including me) purchased to help calibrate home theaters back in the early 1990s. It is great for determining whether this sort of thing is happening. My M2Pro is almost brand new (about eight charges on each of the two batteries) so perhaps I should take some reference measurements. It should be pretty easy: I'll measure some distance from the takeoff pad; I'll takeoff and then hover (which should give me a repeatable rpm for the blades); I'll get it at exactly eye level; and then I'll take the measurement.

I think I need to do this with no wind in an open area (to avoid sound reinforcement from echos off nearby buildings), but other than that, it should be a pretty repeatable experiment.

I won't be able to provide results any time soon, but if I ever do discover something, I'll let you know.

The only two things I can think of that would cause more noise would be splits or chips on the props, or some sort of warpage that changed the pitch. Given the material, I don't think these blades can warp, although I haven't subjected them to any heat (like the trunk of the car in summer Arizona sun).

 

[TheWolfen]

If you are going for real accuracy, you might consider recording barometric pressure and elevation at testing time too. Perhaps there wouldn't be enough difference to measure at different pressure levels but you never know!