S800 alternative props

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DennyR

Active Member
jes1111 said:
I like this arm mod more than the applied tube idea - but if I was doing it myself I'd try it Rob's way - some 0.7mm CF plate bonded to top and bottom, or even perhaps 1-1.5mm strips bonded to the central rib and the edges so the truss openings remained clear.

Tabb said something interesting in another thread - that the Zenmuse suffers from losing the horizon level under certain accelerations, just as all the other solutions do. Yet I've never heard any mention of this. So what's your finding Denny?
Click to expand...

You can tell Tabb from me that is an absolute load of old bollocks, Good bloke Tabb so he wont mind me saying it. The Zen never looses it's horizon. I set it and forget it. I can only report good things about the entire S800 package that I am now using. I was called in at short notice to shoot some of the footage for the new pop video sponsored by SHARK, about thirty five people on set and shot on a Red Epic. The Next-7 footage will cut in OK. A director will always push you to your limits to find what you can really do. When you show up highly recommended it is time to deliver or else.... The S800 performed all day long flying high, flying low, over the sea, through the trees and after a few briefs with the street runners some extremely close-in action around and over the talent. These guys can jump out of the way of anything. I would not have done that without total confidence in the model. Many,Many hours of testing over the last few weeks. A pro shooter cant ask for more. Sure I have a few mods. most of which I am happy to share. Every modeler that I have ever known will always put some kind of personalized mods. on their models. (Tip) blunt your blade tips incase you have an accident, the loss of performance is secondary. Use APC's not Graupners in this situation.
One of the things that I miss about SR helis is the ease of orientation. some MR's are difficult to see but the S800 I fly far out and can always see it's orientation.

When the director pats you on the back and says I never saw footage like this except from a Cineflex I am satisfied with my days work. And my equipment.

Another useful tip is to have your camera roll function on a different stick to pan and tilt and if you have the tilt to work in the same way as a crane or jib. i.e. pull the stick back to look down then a director or assistant will be able to use it also....

We should start a new thread PIMP MY HEXA...
 
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D

DennyR

Active Member
R_Lefebvre said:
Sorry, I guess yeah, all I see are the complaints. Looks like you have nailed the design problem. The truss design was chosen for ease of manufacturing, not performance. It needs reinforcement of the top and bottom skin. I think something similar could be achieved by simply bonding a thin layer of fiberglass or carbon fiber to create a tube.

I just don't think people should have to do this on such an expensive airframe.
Click to expand...

I don't think it needs the bottom as well. If someone does a CFD analysis on this I think you will find that the torsional stresses are focussed at the middle waisted part and the substrate needs to spread in thickness working away from this point. It doesn't need much and using stuff like silicone to bond other material will be very heavy and not effective. You need a bonding material with good hard compression properties applied in the right place to the existing structure.

http://www.fibermaxcomposites.com/shop/-c-65.html

I was able to buy smaller quantities by request.
 
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ChrisViperM

ChrisViperM

Active Member
DennyR said:
One of the things that I miss about SR helis is the ease of orientation. some MR's are difficult to see but the S800 I fly far out and can always see it's orientation.
Click to expand...

Did you mod something on your S800 to make the LED's of the arms more visible....? To me they seem not to be the brightest LED's on the market, I was trying to replace them with that kind of LED from DJI's WooKong status LED, but couldn't figure out what LED it is, It looks like it's a RGB Led.....but no specs avalible anywhere....

Chris
 

D

DennyR

Active Member
I'm just running standard lights on mine, I did have a few extra ones for night shooting but I found the the two red arms to the rear is good enough so I took em off.
Sorting the 1.3 Digital aerials for the video link was a big improvement and also having the monitor on a stand instead of the shoulder mounting helps me work better with the team. Setting up the model to get a perfect forward and reverse tracking without any unwanted yaw is the key to flying it on the limit of visual range. IMHO. My bailout would be switching to FPV and flying it back on the screen. RTH would be my last choice....
 
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R

RancherPete

Member
S800 - still too much vibration... Props?

DennyR said:
Today I really put The s800 through some tough work. I had to shoot part of a new commercial for SHARK soft drinks with a team over from Greece. Very windy but the S800 delivered all day long. in some tight situations. Smooth as silk. As a low level platform working around dancers etc. it just doesn't get any better than this. When I saw what the director wanted, the speeds and proximity of a lot of big palm trees I almost walked away.


Jeff sorry about that long screw I guess you will have to cut in down to 8mm
2500 screws gone out the door so it's hard to see when one is 2mm too long, they are measure out by weight.
D.
Click to expand...

Denny: Its encouraging to hear you speak so highly of the S800 and results you are getting. I only wish my experience was the same. I still have the original S800 props and although I have balanced them as best as humanly possible, and have supported the arms as I explained the other day (with 16MM CF tubes from beneath), the vibration is still terrible... although better than before for what that's worth. I still don't have a DJI Zenmuse but rather the AV200 with a silicone dampening system that has worked very well in the past on my other Hexas and Quads.
Is it really the props that are causing all of this shake at this point and if so what would you recommend to deal with it once and for all?

I would love to buy your prop adapters if you feel that this is the answer. I would also like to know what props you would recommend after all of your extensive testing. I am at 7,000 ft MSL and I believe that this has been a real problem for me with the S800 so I may need to consider this when choosing a prop. Also, I find that my S800 is absolutely terrible in any sort of breeze. It gets very noising and jerky in the air. Could it be that the density altitude is effecting the S800s ability to correct itself? This seems to make sense because when I fly my fixed-wing aircraft the control surface response and all other forms of performance are compromised greatly, so why not the S800? My useable load is terrible on the S800 at 7,000 ft. I have it stripped down to nothing just to get it to hover. I am pretty much at the end of my rope with the S800 so I am looking for one more shot at making this right, if at all possible. If you think that props and adapters are the answer i will certainly give it a try.
 
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A

anyvision

Member
Me i tried 1,3 Video downlink what is a great stable videosignal but noticed that it disturbe my 2.4 ghz tx after about 200 meters. Danger of signal breakdown on the tx. anyone has the same experience and may be a clou ?
 

D

DennyR

Active Member
Pete
In my experience the carbon props are rubbish for a number of aerodynamic reasons as well as the safety aspect and cost of replacement. I would suggest the APC 14x4.7 and slightly blunt the tips then give them a good balance. My arms have only just been modified as I did not feel it was required to stop the vibration. However it wont do any harm and may even improve things still further. It is in the torsional direction that you need to stiffen them So placing materials under the arm will reduce the flex in the vertical plain but it will do very little to stop the torsional movement. This is the critical area as movements in that direction will start an oscillation if the vibration is high enough to create an off-axis movement at the motor shaft. (Likely if you hit turbulence) I would naturally recommend these adapters with those props. The Zen shows no vibration artifacts at all with this set-up. I love this combination and I'm sticking with it. I did some fast descents yesterday and no wobbles even with rudder inputs.

You may see a slight improvement with the graupners but I cant use them on a set as they are very dangerous around the tips.
 

D

DennyR

Active Member
anyvision said:
Me i tried 1,3 Video downlink what is a great stable videosignal but noticed that it disturbe my 2.4 ghz tx after about 200 meters. Danger of signal breakdown on the tx. anyone has the same experience and may be a clou ?
Click to expand...

Interesting, what Tx are you using?

I do have my Spectrum Rx's mounted high on the top plate and the 1.3 is below on the arms.
 
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C

cs8

Member
Today I tried Dennys adapters and Graupner 14x8 props. And I have problem.
I went flying, started slowly until s800 was hovering and than added little bit of throttle. I heard strange sound from one of the props and s800 almost crashed.

So I landed and I saw that one motor starts to vibrate heavy when throttle over half. I tried other prop and it was the same. It even vibrated the same at full throttle with a prop off! And I noticed the same behaviour on one other motor.

Anyone had the same problems? What could I do?
I balanced all the props. I thought it was a faulty prop.

video of the problem:
http://youtu.be/dKziC9w9hBw
 

A

anyvision

Member
same position but insteed of spektrum i use graupner. under testconditions walking by feet after 200meters tx signal goes down to almost zero. my 1,3 has 200mw - may be too much mw causes interference???
 

D

DennyR

Active Member
cs8 said:
Today I tried Dennys adapters and Graupner 14x8 props. And I have problem.
I went flying, started slowly until s800 was hovering and than added little bit of throttle. I heard strange sound from one of the props and s800 almost crashed.

So I landed and I saw that one motor starts to vibrate heavy when throttle over half. I tried other prop and it was the same. It even vibrated the same at full throttle with a prop off! And I noticed the same behaviour on one other motor.

Anyone had the same problems? What could I do?
I balanced all the props. I thought it was a faulty prop.

video of the problem:
http://youtu.be/dKziC9w9hBw
Click to expand...

It sounds like you have a damaged motor.
 



T

Tabb Firchau

Member
Come on now Denny, the Zenmuse is great for short term stabilization I won't argue that, but it gets loads of drift long term. Maybe in very simple moves with minimal acceleration it is fine, but with more complex moves with lots of lateral acceleration the horizon is all over the place.

You can literally see the roll axis drift in this video just from a simple pan input at :45 seconds.

Take a look at this video....it is all over the place

for the record NEX-7 footage will not cut in OK with EPIC, that is just silly. The zenmuse is great for what it is, but you are going a bit overboard.







DennyR said:
You can tell Tabb from me that is an absolute load of old bollocks, Good bloke Tabb so he wont mind me saying it. The Zen never looses it's horizon. I set it and forget it. I can only report good things about the entire S800 package that I am now using. I was called in at short notice to shoot some of the footage for the new pop video sponsored by SHARK, about thirty five people on set and shot on a Red Epic. The Next-7 footage will cut in OK. A director will always push you to your limits to find what you can really do. When you show up highly recommended it is time to deliver or else.... The S800 performed all day long flying high, flying low, over the sea, through the trees and after a few briefs with the street runners some extremely close-in action around and over the talent. These guys can jump out of the way of anything. I would not have done that without total confidence in the model. Many,Many hours of testing over the last few weeks. A pro shooter cant ask for more. Sure I have a few mods. most of which I am happy to share. Every modeler that I have ever known will always put some kind of personalized mods. on their models. (Tip) blunt your blade tips incase you have an accident, the loss of performance is secondary. Use APC's not Graupners in this situation.
One of the things that I miss about SR helis is the ease of orientation. some MR's are difficult to see but the S800 I fly far out and can always see it's orientation.

When the director pats you on the back and says I never saw footage like this except from a Cineflex I am satisfied with my days work. And my equipment.

Another useful tip is to have your camera roll function on a different stick to pan and tilt and if you have the tilt to work in the same way as a crane or jib. i.e. pull the stick back to look down then a director or assistant will be able to use it also....

We should start a new thread PIMP MY HEXA...
Click to expand...
 
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