S800 alternative props

[DennyR]

A few weeks ago I made ten sets of conversion adapters to fit non dedicated props to the S800. Mainly because spares were like gold dust. As the wind was really ripping today I thought lets try em. when I got to the beach I thought no way. The model was swaying about on the ground and the motors were not even running.

I used 14x4.7 APC's and the results were extremely good. It flew for 27 mins on a 11 amp maxamps and the most noticeable thing was that awful ringing noise from the carbon props was gone. A massive saving over the standard carbon props and I think they may even be more efficient. Todays test were without doubt the most extreme conditions that I have ever flown a MR in. I doubt that I will ever use the standard props. again. Its no secret that I am testing the **** out of the S800 to try and find if a fault is still lurking somewhere. So far so good.

 

[R_Lefebvre]

27 minutes! Wow, I totally missed the bus on this one, I had no idea those things could fly that long. What's the secret, in a nutshell?

Edit: Oh, 6S and 320kV motors is a good start. Still, that's incredible. Their claim is only 16 minutes? I assume you had no load?

 

[DennyR]

No load at all, I took off the Zen just in case. I only discharged the battery to 3.7 volts per cell so I could have gone a lot longer. The model was working overtime in the high turbulence but it could still hold a GPS lock hands off for that time. The ESC's were barely warm. I am still hearing about the Flip of Death but not able to replicate it....YET.

None of my small quads would fly in that wind, thats for sure!

WKM settings Basic 240 240 100 160
Atti. 130 130

ADVANCED V.Damp 140 Dist. 160

APC 14.4.7 slow flight

 

[ChrisViperM]

Denny, could you show a pic of your adapters please ?

What also would be interesting if the arm flexing (maybe in more normal conditions than your test) would change with different props. Not very important with a Zen, but still interesting

Thanks

Chris

 

[david.scarbrow]

Denny, with those results for APC (presumably balanced) props has got to be a big leap forward. What you have just achieved I would guess is how to overcome a large and high hurdle for many...ie...the cost of replacement props and of a type that are also easier to source. It will be interesting to see how the S800 now performs with APCs and fully loaded with a Zenmuse attached. I see that you had 10 sets made up...by that do you mean 60 individual conversion adaptesr ? If this is the case would you be willing to sell on a set ?

 

[FerdinandK]

The Graupner 14x8 also could be a good choice.

best regards

Ferdinand

 

[DennyR]

David
Yes I will sell some, but they were made in Cyp. not China so each set is in the order of 50 euro (set of six.) High grade aircraft alum. View attachment 6387

I wont be upset if anyone copies the idea.

 

[ChrisViperM]

Thank you for the pic....I guess you will not make friends with DJI :tennis:

Chris

 

[DennyR]

Denny, could you show a pic of your adapters please ?

What also would be interesting if the arm flexing (maybe in more normal conditions than your test) would change with different props. Not very important with a Zen, but still interesting

Thanks

Chris

I did not have time to check prop balance today so they are straight from the packet. I did not see any movement in the arms like I saw with the carbon blades. I am starting to think that although the carbon are lighter by almost 10 grams I think they are flexing too much or too little and this goes into the arms. You need a day like today to really see what is going on. Noticeably very much quieter. I just ran a pitch check along the blades and the APC is very similar to the DJI carbon but with a little less dia. My guess is that the APC is probably a little more accurate in blade section. I think amongst the heavy lift fraternity there has been some work done to find a better prop than the APC but my findings seem to indicate that it is one of the best.

@ FerdinandK 8 " pitch seems to me to be too high. Maybe with a lot less dia....

 

[FerdinandK]

They will work fine, I promise (much better than the 14x4).

best regards

Ferdinand

 

[ChrisViperM]

I am starting to think that although the carbon are lighter by almost 10 grams I think they are flexing too much and this goes into the arms.

That was exactly what I was thinking, because the arms are not flexing for no reason. Another thing I was just thinking (but never checked) is blade tracking. On a sigle rotor heli blade tracking can be adjusted, but not on the blades of a Multirotor. So even if the Multirotor blades are balenced (left and right weight) perfectly, someone could have serious vibrations due to bad blade tracking. For all those non-single-rotor-heli-guys :

Chris

 

[DennyR]

Thank you for the pic....I guess you will not make friends with DJI :tennis:

Chris

Thats very true. I know that they don't like me talking about how the zen works. They have kept me waiting for six weeks for the return of my Zen brackets so I don't figure too highly in the order of things.

 

[BorisS]

Denny whenever you have some ready to sell, please announce it I will take two sets right away !

Boris

 

[DennyR]

That was exactly what I was thinking, because the arms are not flexing for no reason. Another thing I was just thinking (but never checked) is blade tracking. On a sigle rotor heli blade tracking can be adjusted, but not on the blades of a Multirotor. So even if the Multirotor blades are balenced (left and right weight) perfectly, someone could have serious vibrations due to bad blade tracking. For all those non-single-rotor-heli-guys :

Chris

Sr blades for a flybarless head do have some flexibility built into the design which is adjusted with some different softness O rings. I am starting to think that maybe the DJI carbon blades are too stiff and too thin in section. That noise is coming from somewhere.

 

[DennyR]

Denny whenever you have some ready to sell, please announce it I will take two sets right away !

Boris

First come first served PM me with your details Chris.

 

[BorisS]

First come first served PM me with your details Chris.

want my intention to jump in front of chris. If you'll some additionally for sale at some point please announce it

Thanks

Boris

 

[DennyR]

That was exactly what I was thinking, because the arms are not flexing for no reason. Another thing I was just thinking (but never checked) is blade tracking. On a sigle rotor heli blade tracking can be adjusted, but not on the blades of a Multirotor. So even if the Multirotor blades are balenced (left and right weight) perfectly, someone could have serious vibrations due to bad blade tracking. For all those non-single-rotor-heli-guys :

Chris

That is a good point, I checked some just now and the tracking is not good. The problem with wet layup carbon blades is that the resin is not stable. Heat from the motors will cause em to bend..... Autoclaved carbon is the way to go but its just far too expensive.

 

[DennyR]

View attachment 6408View attachment 6409

Only two sets left now so guess I must make a few more.
As you can see the set comes with a nice fitting washer and nylock nut plus proper cap head HT screws and not those crappy DJI ones that you can use once if you are lucky. Hi grade aircraft grade alum. but don't forget a little light grease on the thread. Don't overtighten. The reason I made ten sets in the first place is because the cost is about the same as making one set.:tennis:

 

[DennyR]

The Graupner 14x8 also could be a good choice.

best regards

Ferdinand

I only have one so I cant fly it, It seems very noisy which is not a good sign. I have always found the high aspect ratio blades are not as good as low aspect ratio blades with less pitch angle. I guess you will have to be the one to go try them on a S800 and be the first.... Those props are not cheap.

 

[FerdinandK]

I already fly the 14x8 on most of my copters, on the hex with the Z15, and on the "fly long, fly far"-quad.

14x8 for hex with Z15:
https://vimeo.com/44931159

14x8 for long flight times (65min):
https://vimeo.com/38908434

14x8 for long distance (6,5km):
https://vimeo.com/47275644

I know that they will work great on the S800, I also have all the parts here to mount them, but until now I was just to lazy to do so and make a video. I might have some time over the weekend. There are not many props out there which can compete with the Graupners.

best regards

Ferdinand