Due to the composite material from which the propellers are made, the composition of this composite is reserved by DJI, they may differ in weight. Therefore, they are matched in pairs and marked. In addition to the numbers 4726, which are no longer a secret, there is an additional designation consisting of a capital letter and a number, e.g. M4, Q1 and others. This means the weight tolerance in which the propeller is located. The differences are very small, reaching 0.01 g and less. Therefore, the selection of the propeller in pairs is very important. New propellers are already selected by the manufacturer, but there may be a mistake and confusion of the propellers after dismantling them. It is also important that at the slightest abrasion of the edge of one propeller or even a small damage, replace it with a new one. The mini 2's motor speeds exceed 20,000 rpm, and vibrations that occur can not only degrade the recorded video, but also significantly shorten the life of the motor bearings. I know this from my own experience, which I wanted to share here. I'd love to know your experiences.

Good post but I think you maximum speed is high, how did you come by that  number?
Remember that balance also depends on how the blades' masses are distributed.
I think the fastest I have seen in a Mavic Mini DAT is 14,000rpm, my assumption is that Mini 2 rpm's are similar to the Mavic Mini's.
I might have seen 16,000+rpm in an FPV DAT, whatever it was it was faster than any Mini DAT that I have looked at.

"The differences are very small, reaching 0.01 g and less."

How accurate is the scale you used? And as Sean points out you balance a propeller other than by weighing it.

What is the source of M4 Q1? would it not be the production series that corresponds to a mould. I mean, the inscription is done during the molding, not after a post-manufacturing measurement.

Sean-bumble-bee Posted at 4-12 01:06
Good post but I think you maximum speed is high, how did you come by that  number?
Remember that balance also depends on how the blades' masses are distributed.
I think the fastest I have seen in a Mavic Mini DAT is 14,000rpm, my assumption is that Mini 2 rpm's are similar to the Mavic Mini's.

I was measuring the rotation by sticking a marker on the propeller. however, the measurement was unstable. At times the result exceeded 20,000 rpm. However, there may have been a measurement error. I think that the differences in the weight distribution in the propeller is due to the uneven distribution of the composite. Please note that Master Airscrew propellers are not paired due to the homogeneous material, probably plastic.

Here is an enlarged photo of the propeller. This shows that the propeller weight designation was, I believe, given by a different process. The K2 designation is clearly a different font and is not compatible with other designations. So my conclusion is that the propellers are weighed after the mold injection process. I didn't have access to the 0.05g scale today. They sent her for legalization and she'll be back next week. I weighed the propellers on a scale with an accuracy of 0.1 g. Even with this accuracy, the results oscillated around 0.6-0.7 g. I checked the markings of all the propellers I have, including the damaged ones, and there were: C1, C2, E4, K1, K2, K4, L2, L3, M4, N1, N2, 01, 03, 04, Q1. Curiosities also include slight corrosion of the mounting screws, which may occur when flying in fog or over the sea.

Always replace the props in pairs not just the one with damage.  DJI match the props to the mold so they should not be mixed up.

Finally managed to weigh the propellers. I had a scale with an accuracy of 0.01g at my disposal. Measurements have shown that the differences between the propellers reach 0.05g. However, when combined in pairs and marked with the same symbol, their weights are practically identical.