S800 alternative props
- Thread starter DennyR
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AddictiveRC
Member
T-Motor CF 15 x 5.5 Props tested on T-Motor MN4014 Motors
We had a chance Saturday to test some of the new T-Motor CF 15 x 5.5 Props on our new Vulcan UAV 900mm Quad Frame.
We are very pleased with the smooth results!
Our Quad Has T-Motor MN4014 Motors and they love these props.
They behave nicely in wind and are very quiet with little to no Motor wine.
Our Qaud has an AUW of 12 Pounds RTF with 6S 8000mah Lipo.
Flight time was just about 15 min.
Very impressed with these props.
Please note attached photo is with our original props.
Cheers, John W.
AddictiveRC, LLC
View attachment 9045
We had a chance Saturday to test some of the new T-Motor CF 15 x 5.5 Props on our new Vulcan UAV 900mm Quad Frame.
We are very pleased with the smooth results!
Our Quad Has T-Motor MN4014 Motors and they love these props.
They behave nicely in wind and are very quiet with little to no Motor wine.
Our Qaud has an AUW of 12 Pounds RTF with 6S 8000mah Lipo.
Flight time was just about 15 min.
Very impressed with these props.
Please note attached photo is with our original props.
Cheers, John W.
AddictiveRC, LLC
View attachment 9045
Attachments
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AddictiveRC
Member
This is a New Photo of our Quad with the T-Motor 15 x 5.5 CF props we tested.
Cheers, John W.
View attachment 9070
Cheers, John W.
View attachment 9070
Attachments
I also want to know how they perform in coax setup. But I thought maybe the top and bottom props being closer together may not be ideal, and are better being further apart?? Has anyone tried this?
Thanks
RancherPete
Member
John: I am flying my S800 at an elevation of 7,000 ft. MSL. So, I lose quite a bit of lift due to density altitude. It's a little better in the winter with cold air but the summer time is not good and I have to strip down my S800, lose the full-size DSLR, use one lipo and go with a Sony NEX5N to save on weight. Its killing me. I have been using the stock DJI CF props and have also tried the APC 14 X 4.7 with Denny's prop adapters. The APCs are definitely smoother (less vibes to the video) but the lift is not any better than the CF DJIs. Will the props that you have mentioned here possibly have greater lift due the higher pitch of 5.5? Any info or experience you (or others) can share would be greatly appreciated as I am still trying for the very best results possible out of my S800 at this high elevation and Spring is just around the corner.
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I think the Gemfan 15x4 is the best, so long as you balance it in the vertical and horizontal plain. Don't forget that using adapters will increase the overall C of G of the motor so if you have ANY imbalance it will be magnified into a torsional vibration along the arm, that once exited will only get worse to the point of self destruction. It is a good way to find if you have any problems with balance, motor bearings or ESC timing etc.:tennis:
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MombasaFlash
Heli's & Tele's bloke
The recent trip to the Rift Valley in Kenya found the S800 had to work hard with the altitude and heat on standard DJI props. I don't really like them much and I agree about the nasty whistle they make. Does anyone have any idea what pitch they are?
Anyway, they will have to be changed for steeper pitched props if it flies there again but there is not a huge choice of easily obtainable alternatives. APC 15's and Graupner 14's are about all there is - other than Zoar wooden props.
What is the feeling with wooden props? Do folks like them?
I have been happy enough with the nylon APC's on the AD8. They are robust, easy to balance and generally fuss-free. I have never had one break.
Anyway, they will have to be changed for steeper pitched props if it flies there again but there is not a huge choice of easily obtainable alternatives. APC 15's and Graupner 14's are about all there is - other than Zoar wooden props.
What is the feeling with wooden props? Do folks like them?
I have been happy enough with the nylon APC's on the AD8. They are robust, easy to balance and generally fuss-free. I have never had one break.
Hi
Have you watched this video with Xoar Wood ?
http://vimeo.com/64453610
I feel I want to buy Carbon T-Motor now.
No more heavy adapter.
Have you watched this video with Xoar Wood ?
I feel I want to buy Carbon T-Motor now.
No more heavy adapter.
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MombasaFlash
Heli's & Tele's bloke
I bought some Gemfan 15x5 wooden props on the strength of Denny's recommendation and took them off again because there appeared to be no change in the degree of vibration and wobble of the skids (due to the loose play in the Secraft retracts). This not to say I will not try the Gemfans again someday, the next time I fly at a bit of an altitude, for example, but for now the stock DJI items are back on. I don't really like them much. They are noisy as HELL.
Main issue to overcome at the moment is the intermittent height loss. Whether this indeed is due to vibrations affecting the IMU remains to be seen but I am eager to try out the IMU.v2 that is claimed to eradicate the problem.
Has anybody (other than Krleas and Additive RC) tried these T-Motor props? They do not look a million miles different to the standard DJI S800 items but Addictive RC seems to think they are quieter.
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The most important factor to consider is that adapters raise the center of mass inside the motor so any imbalance is magnified. Imbalance does not just come from the props. It can be the result of differing resistance across each winding phase. The best use of these adapters is so that you can use smaller props such as the 14x4.75 Slow flights because they will deliver better performance in high winds. The optimum lift efficiency is not the best for stability because rpms. get to low in the descent and yaw. That is one area where SR's are much better because the idle up function keeps head speed at a constant high throughout the flight.
If you run the head speed too low on a SR you will see MR type instability as partial blade stalls occur.
As with Full size heli ops. you can get a natural frequency harmonic that will create vibrations out of nowhere, these will often go away just by a slight change in head speed. With MR's it can also occur but you can't simply change the pitch angle without changing the prop.
If you run the head speed too low on a SR you will see MR type instability as partial blade stalls occur.
As with Full size heli ops. you can get a natural frequency harmonic that will create vibrations out of nowhere, these will often go away just by a slight change in head speed. With MR's it can also occur but you can't simply change the pitch angle without changing the prop.
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RancherPete
Member
Hi Denny: While I have had a good experience with your prop adapters and the APC 14 X 4.7 I still deal with issues when flying at this high elevation that I live at of 7K ft MLS and greater. As I have mentioned before I must strip my S800 down to one lipo and very light camera in order to have a reliable hover and lateral flight without dropping like a rock. I am still using WKM by the way. Do you have any updated suggestions for a prop that may suit my needs as I still have these issues and the photo season is rapidly approaching around here. I can go with ones that fit on your adapters or mount straight onto the S800 motors. I just need something that works better up here and can allow for a heavier load. Any tips?
In a rarified atmosphere the envelope for finding the best all round prop. will be smaller. It could be that your motors don't have enough KV to allow for the higher rpm that is needed. Adding pitch is not the answer as it will induce a blade stall, That sounds like what is happening now. you need less pitch, more blade area and higher rpm but I don't know where you can find it.
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RancherPete
Member
Thanks Denny. I appreciate your comments.
RancherPete
Member
Denny: I see that there is now an APC 15 X 4 prop in both orientations. Did you happen to get a chance to test these? At the time I bought your prop adapters for the S800 I think there were only the 14 X 4.7 available so I wonder if these would give me any abetter lift at this high elevation that I am at. I was also thinking of trying the Foxtech 15 X 7.5 but then I recalled what you said about the probability of a steep pitch contributing to a potential stall.
http://www.rcdude.com/servlet/the-2320/APC-Thin-Electric-Pusher/Detail
http://www.foxtechfpv.com/1575-carbon-fiber-propeller-cwccw-p-543.html
Pete
RancherPete
Member
Denny, thanks for your reply. I will order a set of them and give them a spin. I'll let you know how they work. Have a great weekend. (oops, I actually thought it was Friday already!)
Pete
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