I have seen several threads in these forums that go something like this:
The DJI engineers who designed the OEM props were given a set of requirements around performance, durability, noise, manufacturability, variability, and most importantly (my guess), safety and cost. When it comes to performance, the engineers were also told (likely by the product lead) to optimize for a specific flight mode, i.e. ONE of the following: climb, hover, cruise, or max forward speed. Production cost at scale was likely a top requirement. And the most impactful decision, which throws some requirements under the bus in favor of others, was likely the choice of propeller pitch.
So, it's entirely possible that someone else could design propellers that optimize one requirement over the other. Examples:
- Use a more expensive material to make harder or thinner blades, throwing cost and safety out the window in favor of general performance.
- Steepen the propeller pitch, increasing maximum speeds but requiring more power to hover.
- Flatten the propeller pitch, making lower noise and lower power requirements at hover but killing maximum speed.
- Use an exotic material, harder to mass-produce but OK for a kickstarter person to make each one by hand.
- Adding a third-blade in combination with any of the above, also produces similar trade-offs.
So there it is. When another OP reports good results with third-party props, don't be so skeptical.
OP: Should I use third-party propellers on my Phantom for better <X>?
Overwhelming Response: No, the DJI engineers know best and already gave you the best possible propeller design!
I am writing this post to dispell a myth that bothers me, as an engineer. The DJI engineers are amazing, I do not question that. The myth here is that there is such thing as a "best design" for anything other than a stated set of requirements, or, more precisely, that the engineers magically optimized their design for the OP's specific set of requirements. That is simply not possible. The conventional wisdom is dead wrong.Overwhelming Response: No, the DJI engineers know best and already gave you the best possible propeller design!
The DJI engineers who designed the OEM props were given a set of requirements around performance, durability, noise, manufacturability, variability, and most importantly (my guess), safety and cost. When it comes to performance, the engineers were also told (likely by the product lead) to optimize for a specific flight mode, i.e. ONE of the following: climb, hover, cruise, or max forward speed. Production cost at scale was likely a top requirement. And the most impactful decision, which throws some requirements under the bus in favor of others, was likely the choice of propeller pitch.
So, it's entirely possible that someone else could design propellers that optimize one requirement over the other. Examples:
- Use a more expensive material to make harder or thinner blades, throwing cost and safety out the window in favor of general performance.
- Steepen the propeller pitch, increasing maximum speeds but requiring more power to hover.
- Flatten the propeller pitch, making lower noise and lower power requirements at hover but killing maximum speed.
- Use an exotic material, harder to mass-produce but OK for a kickstarter person to make each one by hand.
- Adding a third-blade in combination with any of the above, also produces similar trade-offs.
So there it is. When another OP reports good results with third-party props, don't be so skeptical.