Propeller Nicks

[Bluesog]

How much of a propeller nick is too much and should be replaced. When packing my mini 4 away for the day I noticed a small nick. While flying everything seemed fine. New to drone flying.

 

[old man mavic]

@Bluesog ,compared to the cost of having the drone come down, and sustain damage to itself ,or something else, due to a damaged prop failing during flight
it is always sensible,to me anyway ,if a prop shows any sign of damage ,then in the case of the Mini 4 pro i would without hesitation to replace the pair of props on that particular motor

 

[Yorkshire_Pud]

Post a photo, the risk and detrimental effect of a nick depends on where it is located and its shape but in general I'd go with @OMM's advice.
One thing you might find interesting to do is hover the drone in front of your, touch the mounting point of the nearest motor with a finger tip and feel the vibration of that arm end. Spin the drone through 90deg or so and repeat, repeat, repeat.

Assuming you decide to replace damaged blades then replace BOTH blades on each affected motor with a pair of blades taken from a sealed DJI pack. The blades are supplied in weight matched pairs, for centrifugal balance, and should be fitted as such to ONE motor.
If you mix-and-match old-and-new you risk having unbalanced blades on one or more motors and that will cause vibration.
Assuming you follow those instructions repeat the above touch and feel tests and 'see' if the vibrations felt are reduced.

 

[old man mavic]

@Yorkshire_Pud ,with the greatest of respect to your goodself,it doesn't matter how many pics of said damaged props ,that we see on this forum
none of us are really qualified to advice another flyer, on whether or not a particular propellor is fit for flight
your advice about checking for vibrations,is also fine, if you are confident and have the expertise to put your hands close to a fast spinning blade,and on a Mini drone, although the results of a contact might not cause much of an issue ,that would not be the case with a larger drone

 

[Yorkshire_Pud]

@Yorkshire_Pud ,with the greatest of respect to your goodself,it doesn't matter how many pics of said damaged props ,that we see on this forum

But the location of a nick can be seen in a photo, a nick near the blade root may lead to the loss of a significant portion of the blade and the possible loss of the drone. Whereas a nick near a blade tip that leads to loss of the tip is likely to be survivable long enough to get the drone home.
I also suspect a nick on the thicker leading edge will not be as 'dangerous' as a nick in the thinner trailing edge, I suspect a crack stemming from the latter will grow more quickly than a crack stemming from the leading edge.
From memory the cracks I have found in mavic mini blades ran from the trailing edge inwards/forwards.

That's the reason I asked for the photo.

Of course all this is moot if the OP follows your advice.