Anyone use NON OEM props?

[Syphen]

I am a mechanical inspector, I am in China right now and know the system here when it comes to manufacturing. I have compared the non and original parts closely, and I can see no difference at all. The probable fact is that the non oem parts are 99% made by the same company that make the props for DJI, sure the same molds and plastics, but just different colours. Of course, if you buy the oem parts made for direct supply to DJI you will pay the top dollar price. But look at how much money can be made by using the same molds to knock out many different colours on the side. Sometimes, Chinese quality is in fact good. Just look where the DJI range are made!!
I can't believe that the differences being found are so dramatic as to affect flying characteristics, these props are identical in every way. I think it is just that because they have not come in a DJI box, they cannot be good.This is why I asked for more evidence or disaster stories.

I took some photos of the oem and non oem I will post up as soon as I can.

Well, I can see one quick difference: The OEM props seem to have 4x cap-head allen machine screws holding the blades to the hub assembly. 2 from each direction. The non-OEM seem to only have 2 longer ones that are threaded from one direction.
Also, I'd be curious if the blades were sorted based on weight for OEM QC and paired up within a certain deviation for a completed blade assembly for balance purposes. And just because a part is made in the same plant with the same materials doesn't mean that they hadn't reached end of life on the mold for OEM parts - refurbished it on their own dime and started up a knock-off production run on a worn out mold.

 

[steve.r]

Thanks for your feedback Syphen, but there are not four screws holding the blades in place. Just two pins, that have been pushed into undersized holes. The indentation you have compared to a cap head screw is just a round mark in the end of the pin where the machine in manufacture locates to insert the pin. As for weight, I don't have accurate scales here to compare, but looking at the blade in my hand, I can feel no rough edges or see any flash from the mold. These are well made

 

[rambisetr]

I'm new to drones and inadvertently broke one of these on "quality" oem blades by accidentally grabbing the drone wrong. So I went.on Amazon and read some reviews and found two different companies making blades that fit and had good reviews. The first set I have opened are red and white. All the blades went on perfectly except one. Appears the connectors are just a tad off spec and won't turn in. The others all fit fine and I got 8 blades for less than 4 oem so I'm not going to cry about 1 bad one. As far as performance goes, I have seen no difference in sound or hovering or speed. Works like the oem. Haven't tried the other set yet but am optimistic since they came in a very nice case. Just my 2 cents.

 

[John Harvey]

Non OEM blade looks good!!,, if it clips into the motor with no issues or physical force then I would accept it as good. Interesting to get some feedback from people who are using these..

 

[LotusFan]

I tried some orange aftermarket props purely for style...they were so stiff at the joints they would close up during flight and down came spark, near a crowd of people! I got a refund and never again! I have a video of the crash, but not sure how to post it here.

 

[steve.r]

Can I ask how being stiff at the joints with centrifugal forces when turning, did they close up? sort of goes against physics..

 

[Ron_Dog]

I found the after market props gave a more unstable flight in hovering as well as they are louder and made with a thin plastic so they break very easy. Getting ready to try carbon fiber next.

I replaced them with OEM props yesterday, and they indeed seemed to help with stability, and overall flight performance.

 

[Ron_Dog]

I wonder if DJI is ever gonna make some "quiet type" props for the Spark,like the one's for the Mavic Pro?

 

[Syphen]

I replaced them with OEM props yesterday, and they indeed seemed to help with stability, and overall flight performance.

Instability (and loudness) screams blade imbalance to me.

 

[Ron_Dog]

Instability (and loudness) screams blade imbalance to me.

It could be?

 

[Ron_Dog]

Thanks for your feedback Syphen, but there are not four screws holding the blades in place. Just two pins, that have been pushed into undersized holes. The indentation you have compared to a cap head screw is just a round mark in the end of the pin where the machine in manufacture locates to insert the pin. As for weight, I don't have accurate scales here to compare, but looking at the blade in my hand, I can feel no rough edges or see any flash from the mold. These are well made
That is a "peen" to expand the ends of the pin! This keeps it in place.

 

[netfolks2000]

I am a mechanical inspector, I am in China right now and know the system here when it comes to manufacturing. I have compared the non and original parts closely, and I can see no difference at all. The probable fact is that the non oem parts are 99% made by the same company that make the props for DJI, sure the same molds and plastics, but just different colours. Of course, if you buy the oem parts made for direct supply to DJI you will pay the top dollar price. But look at how much money can be made by using the same molds to knock out many different colours on the side. Sometimes, Chinese quality is in fact good. Just look where the DJI range are made!!
I can't believe that the differences being found are so dramatic as to affect flying characteristics, these props are identical in every way. I think it is just that because they have not come in a DJI box, they cannot be good.This is why I asked for more evidence or disaster stories.

I took some photos of the oem and non oem I will post up as soon as I can.

It comes down to the particular quality inspection control within the company making the aftermarket props. The Chinese how their own internal issues with companies trying to copy other company's products, not always maintaining the same quality. I'm sure some do. But how do you know which products are of high quality? I suppose by just trying them. THAT, I think, is the risk other posts are referring to. Some may really be fine, but it depends on the quality control of any particular company. It is similar with auto parts here in the U.S. Some aftermarket parts are very good. Some aren't.

 

[steve.r]

netfolks, I agree, it does all come down to quality control, and your reference to auto parts is true enough for sure. But with any non-oem part, until they are really tried and tested we do not know with any confidence. For us that are using them and have had no negative flying characteristics it can only boost the camp that says 'yes' it is ok to use them. It's like people who decide to put a rubber strap on a Rolex watch, the purists will always cry blasphemy, but if it works, it works

 

[Syphen]

netfolks, I agree, it does all come down to quality control, and your reference to auto parts is true enough for sure. But with any non-oem part, until they are really tried and tested we do not know with any confidence. For us that are using them and have had no negative flying characteristics it can only boost the camp that says 'yes' it is ok to use them. It's like people who decide to put a rubber strap on a Rolex watch, the purists will always cry blasphemy, but if it works, it works

I sort of disagree with the blind "requires testing" statement when it comes to airfoils and propellers. This field has been intensively studied over the past 100 years... Fluid Dynamic simulations on airfoils and such are available at reasonable prices for airfoil/blade design so almost any company can start designing this stuff and getting reasonable pre-prototype results. We also know the results of having a propeller out of balance and the requirement for them to be balanced. Because the aftermarket blades are being made as cheap as possible - I doubt that the companies are weighing the blades individually and sorting that weight so that completed propeller assemblies are within spec of each other. Also, batches from the mold should be measured for tolerance. As I mentioned, due to the short length of these blades, a very small fraction of an inch difference in length (QC!) can result in poor blade performance.

 

[steve.r]

Sorry Syphen, but do you honestly believe that each set of blades are individually weighed and assembled in this way? The Chinese are kings of mass production, i am here I have seen it. They can mass produce a product so cheaply it is amazing that they don't give them away. You can spend £10 for original props with the DJI logo on the box, or you can buy a non oem for a fraction of the price (to suit personal individuality) These props are most likely made in the very same factory, but labeled differently. It is just a licence to make the purist spend a lot, and say 'i don't want to risk it' to everyone else.

Took my Spark up to 250 meters today, and it RTH within 1 meter

 

[Syphen]

Of course I don't! Even making an assembly to do that automatically would slow production down a little. I'm just throwing out things that would result in a higher quality prop. I get that you say they are made in the same factory but I can see in your pictures that they use different molds (markings are different) and the assembly technique is a little different with the pins.

Once I get a Spark, I'll order up some of the non oem blades and do a proper comparison - measurements, weights and balance. I'll come to my own conclusions about them.

 

[steve.r]

Sure, this is what a forum is all about, differences of opinion. Good discussion, we can all add to the mix. Now go get yourself a Spark as soon as possible, you will love it...

 

[Denny]

Sorry, brand new here but am contemplating a Spark soon.
I saw some vids of a Master Air Screw prop change on a Hubsan 109. It performed better and, more significantly, lowered the tone of the prop sound to a more pleasing, non-bee swarm, level. Hearing the Spark sound, has this been a note of concern or of interest?
Just curious.
Thanks for your patience...

 

[steve.r]

lol, mine sound like an angry Wasp no matter the props, but i use in sport mode mostly. I find it quieter in normal mode. Not something that worries me, when it is, say 10 meters up and climbing the sound start to fade anyway. hth

 

[s2 Web Parrot]

I am not asking you to 'risk' anything, but boldly announcing that you would not 'risk' it immediately puts fears in other people's minds. I see no fear and experience no issues.

Lighten.... There was no "boldly" tone in his post. Geez... A simple statement that the poster feels there is risk in using non-OEM parts is a reasonable presumption. Without quantifiable, objective measures that a knock-off product is equal to, or superior to an OEM products is wrong. Period.

If you fly with non-OEM parts, and flight failure occurs, causing damage to your aircraft there will be no warranty or DJI Care coverage. That's a "risk" you take.