Prop loading affecting Video quality ?

[CopterCam]

Whilst waiting for some new APC 1047's to arrive I could not resist the good flying weather so I decided to use try the Gaui stock props. I think they are GWS 0845, I was conscious of the limitations with regard to lifting capabilities so I exercised some caution and stripped the self built camera mount.

What I discovered was surprising............. the APC's had been exhibiting a wobble on fast descent, while the GWS props had no wobble on fast descent but had, as expected on fast ascent. It was apparent that the GWS has a louder sound, it was almost like a rumbling exhaust ?

Confident that the GWS's where up to the the job I decided to mount a GoPro HD with velcro from the bottom plate and was very surprised with the video results. I fully expected to see a lot of vibration but the video image was excellent, no jello and smooth.

I reverted to the APC's and detected a slight vibration and occasional jitter. I am happy that the props are true and balanced and if anything the GWS props are worse for wear. I am of the opinion that the APC props are affecting the frame with their more powerful loading ?

I am considering trying 9in. GWS props or perhaps a 3 Blade ?

Any thoughts or opinions ?

Sid

 

[RTRyder]

Whilst waiting for some new APC 1047's to arrive I could not resist the good flying weather so I decided to use try the Gaui stock props. I think they are GWS 0845, I was conscious of the limitations with regard to lifting capabilities so I exercised some caution and stripped the self built camera mount.

What I discovered was surprising............. the APC's had been exhibiting a wobble on fast descent, while the GWS props had no wobble on fast descent but had, as expected on fast ascent. It was apparent that the GWS has a louder sound, it was almost like a rumbling exhaust ?

Confident that the GWS's where up to the the job I decided to mount a GoPro HD with velcro from the bottom plate and was very surprised with the video results. I fully expected to see a lot of vibration but the video image was excellent, no jello and smooth.

I reverted to the APC's and detected a slight vibration and occasional jitter. I am happy that the props are true and balanced and if anything the GWS props are worse for wear. I am of the opinion that the APC props are affecting the frame with their more powerful loading ?

I am considering trying 9in. GWS props or perhaps a 3 Blade ?

Any thoughts or opinions ?

Sid

I don't know how APC got the reputation they have because quite honestly I find them to be pretty much crap, they don't track well, the overall fit of their adaptor bushings is poor, and the balancing is terrible. Unfortunately for some sizes of props, especially pushers, they're the only game in town so its deal with problems or don't fly.

I use Graupners on every multi that I can, only available in 10 and 11 inch sizes though, so for the smaller quads that need 8 inch props I use EPP which have proven to be decent enough. Graupners are made from very stiff material and have their own unique effect on how a multi flys, if you look at one next to just about any other prop you'll see a very different profile on the blade, there isn't much flex to them and the control response I find to be a lot sharper than with other props.

So to me the experience you had with APC is not unusual but more like very typical, they tend to cause more problems than they solve and while I know there are a lot of people that swear by them, I swear at them whenever I have to use them

Ken

 

[CopterCam]

I don't know how APC got the reputation they have because quite honestly I find them to be pretty much crap, they don't track well, the overall fit of their adaptor bushings is poor, and the balancing is terrible. Unfortunately for some sizes of props, especially pushers, they're the only game in town so its deal with problems or don't fly.

I use Graupners on every multi that I can, only available in 10 and 11 inch sizes though, so for the smaller quads that need 8 inch props I use EPP which have proven to be decent enough. Graupners are made from very stiff material and have their own unique effect on how a multi flys, if you look at one next to just about any other prop you'll see a very different profile on the blade, there isn't much flex to them and the control response I find to be a lot sharper than with other props.

So to me the experience you had with APC is not unusual but more like very typical, they tend to cause more problems than they solve and while I know there are a lot of people that swear by them, I swear at them whenever I have to use them

Ken

They certainly command some popularity, they were recommended to me by another user as being the MRC props of choice but I share your reservations. I found them to be extremely brittle and if a blade of grass as much as looked at it oftentimes it would result in a chip. I am going to try others now without the feeling of betrayal. The end justifies the means and if the video quality shows a marked improvement for this particular platform, enough said.......

Sid

 

[Bartman]

were the apc props the same size as the ones you had on order? maybe we're seeing a trend toward more highly loaded smaller props?
i pulled 12" props from my X650 and replaced them with 11" Graupners. so far it flies much better.
lastly, i've got wood Xoar props on order and should have a pirep by the first week of april. i'm hopeful they'll be another step up in terms of performance and smoothness from the graupners. ken is also getting a set from my order so he'll be able to comment as well.
bart

 

[DennyR]

Vibration is the number one killer of good aerial footage. We can put that into 5 main areas of disturbance.
1 Imbalance caused by motor torsional vibration . Caused mainly by esc timeing over advanced
2. Motor mechanical imbalance.
3. Prop imbalance (mechanical)
4. Aerodynamic shudder caused by the angle of attack on the blades exeeding the stall angle, mainly in the descent.
5. Torsional vibration amplified due to insufficient rigidity in the motor arms.
The use of very high sensitivity gyros is the first step to achieving proper image stabilisation but they can only operate in a vibraion free environment.

Stuff is on the way to do this but needs to have the vibration issue fixed in the first instance.

 

[CopterCam]

Bart,...........the props on order are the same APC 1047 as used. The difference in video quality only became apparent when I used the GWS 0845 props. I feel the reason is point number 5 that DennyR posted in his excellent reply.

The extra oomph ! of the APC 1047's is transmitting a vibration to the arms of the Quadframe that is not present when using the GWS 0845's. The reason for the wobbles is beyond me but is likely to be any one or combination of the other factors listed by DennyR . The only flight criticism when using the GWS 0845's was the wobble on fast ascent, although on reflection it was more of a pendulum effect possibly caused by the rough mount of the GoPro HD under the bottom plate ?

Sid

 

[Emowillcox]

Props

Wondered if anyone had recommendations where to buy spare props?
Thanks

 

[Bartman]

emo,
what sort of props are you looking for and where do you live? what are you flying and what size props are you using?
thanks and welcome to the forums!
bart

 

[Droider]

Graupners for me.. Ive tried um all but the wooden ones. There are some new carbon fibre ones out in Australia but I think they are only available in 12'.. Ill do some more digging

Graupners you can get um here and they do supply in to the states

http://www.electricwingman.com/propellers/graupner/elektro-prop.aspx

 

[Bartman]

i'll have a report on the wood ones sometime next week. just from the look and feel of them, i like them a lot so far.
bart

 

[Emowillcox]

HI Bartman... I live near Houston, Texas now... but funny you should reply to me I saw some of your post and noticed you live in Milford. I lived there the first 7 years of my life spent alot of time with my father flying RC planes and control line there, but now been in Texas for a long time. Miss fishing in those creeks for trout and the farm ponds for bass ;-)
I have a small Gaui-330 and a little bigger kind of home made machine that a guy in Florida made. I am looking for replacement props. IT came with 10x4.5. The places I use to deal with don’t carry the counter rotating props. I think for now I need some cheap props until I get a little better with the quad, but then maybe there is a recommendation for upgrading to higher quality prop for smoother flying and video. My back ground is in TV production and photography so my goal is to get video footage with my quad eventually. Right now I am using helicopters to get aerial photos and have done some video with a friend, but the cost to get smooth footage on a heli was just too much. Once I saw some of the results from the mutlicopters I decided to start playing with them. Thanks for all the time and tips.
Emo

 

[1001 Copters]

Hi there,

I will recieve on april ( expected time is 10 april) a batch of 13x6.5" XOAR wooden prop.
I also asked for other references ( in 12,13 and 14 size) to make some tests.
I have finished my customer machine and I will attack my motor/prop bench test this week end.

If you have particular demand on prop: size, pitch, ask for it, I will place it in my next order to XOAR.

I have to make a video about quality difference between APC and XOAR props, one point is mentioned in this topic: the poor quality of the centered hole in the prop: on APC it's crappy, on XOAR it fits perfectly.
I will of course publish the results