S800 alternative props

DennyR

Active Member
I am using a standard Spectrum 2.4 with battery telemetry module. On the 1.3 I am using channel 7. The 1.3 is tucked away underneath the two carbon plates and the three spectrums are mounted high (2.5") on some insulation board. No line of sight contact.

As the subject of high priced zoom lenses used for high end TV and cinema production was touched on recently. They are actually not that special in terms of optical res. Some of the EOS zooms are actually better. What you pay all that money to correct is a phenomena known as breathing. When you make a large focus change as in a differential focus shot the lens makes a slight zoom at the same time. I don't think we need to worry ourselves too much about that. FWIW....

Done a bit more testing with the S800 on the stiff arms and all is well and building on the reliability aspect. I always still take the precaution of strapping the model down on a workmate, then snapping the throttle open a few times in different modes to check for any motor malfunction. I do this as a pre flight check before each days flying. If it's gona fail then that is probably when....

Also remember to do a range check at the same time.:tennis:

I also avoid the autonomous flight modes when shooting. Coming home etc. mostly I use manual and atti.

GPS will fight you sometimes when you want some freedom.
 
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3dheliguy

Member
Hey Denny,

Your doing a great job for the S800 owners out there. I just had a question, I can't seem to get the S800 to fly good in Manuel mode, and I really don't like attitude mode but for more hovering. Where would be a good starting point for the gains in Manuel mode. I'm not an owner of a S800 but I fly them with my friends, and I haven't had a ton of time to get the gains down for an up coming little trip so anything that could help guide would be great.

Thanks
 

DennyR

Active Member
My gains are usually around the 170 mark. If I am flying fast then it's better in Manual but when I slow down and want to move slower in the turns I switch to Atti and if I want to hover and do a slow slow pan or a stills Pano sequence I go to GPS. I think it's really down to personal choice and what your happy doing. I try to make my flying such that the camera operator has to do very little. Then I can let the Zen do it's job. FWIW....:tennis:
 
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BorisS

Drone Enthusiast
hit another person ;( I was actually building/setting up the bird together with him and he was testing it the last couple days. Really hurts to see this !



Boris
 
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DennyR

Active Member
Poor Guy. There's a lot of damage there. I did see some white flashes. But even so it should never happen. I guess it was all the latest stuff.
 

BorisS

Drone Enthusiast
Yeah ! Or at least a general call out keep the s800 on the ground until they find something ! Even if they replace it just a matter of time were something serious happens ! Not to be disrespectful but when you hear about it from other people you always think maybe they did something wrong, but we really setup this machine checking it all better than mine and than this happens. This makes you think that you don't have it in your hands its just random at the moment ! Im just a bored guy buying these copters and building them for fun ! But in Marown case he wanted to work with this machine and get his investment back, which hurts double !

Boris
 

BorisS

Drone Enthusiast
Japp its was all purchased about 2 weeks ago. V4 ESCs V2 or whatever MC etc. The centerplate was actually different than mine. The lock downs for the arms were more robust and had little fins on them.
 

DennyR

Active Member
Boris

I hope you can help me with this theory. I think what happened then was that the pwm signal wire shorted into the carbon reinforced plastic arm. With any luck that arm is not broken so we can check it. I cant think of any other reason why this is occurring after a period of time. It must be the way in which some arms are rubbing through the shellac coating. Never did like that idea. It is also very strange why the main power lines are such small gauge. How can they not get hot. It has to be said that the FOD has not been happening to other DJI frames on such a regular basis. so that must tell us that it is in the frame somewhere. If not the arms then the Power board. When my S800 came back from DJI repair they rebuilt the arms so I guess they took some time over them. They also replaced the top plate.

I would be much happier seeing all of these arms being rewired with silicon coated wires. And then reinforced to make them more rigid. If I were redesigning them I would also reduce that dihedral angle. :upset:
 

R_Lefebvre

Arducopter Developer
I wonder if it is as you say, one motor slowing/stopping, and then the rest is just an avalanche from there. We looked at this closely because we saw that hexas flipped really badly when a motor failed, even though the theory is that they should be able to sort of fly. The problem is a complicated control interaction. Hopefully DJI solves it before somebody gets hurt. That was a really close call.
 





dolby

Needs more bacon!
Wow thats horrible!!! great video of it happening though. You can see that the fod wasn't due to a motor stopping. It was because other motor(s) went full bore. Has any one tested what happens if the PWM wire is shorted out? does it make the ESC open up full speed? Simple fix if thats the case.
 

DennyR

Active Member
It looks like motor No.4 lost power, it sank and then the opposite motors opened up to arrest the descent. It would be really useful if you could check the following. Are the capacitors still attached properly on motor 4 or 5 ESC's. Do you have a short to ground on the PWM or red wire. Check that on the top plate above the socket header. Just pull the wires from the MC and check them at that point. I think I am satisfied that the problem was not in the MC. In fact the response time to open up the opposite motors would suggest that it was working very well. It is in the arm or the ESC. Could even be that the power wires are getting hot enough to melt the solder. They are too small.

It would be very useful to know if the motors and the ESC's on 4 and 5 are still working.

I expect that right now you are too upset to even look at it but this information could be useful in the quest to find the truth.
 
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R_Lefebvre

Arducopter Developer
The flight controllers should never open up all the motors to stop the descent, or control the yaw. #1 priority has to be maintaining attitude. Let it fall straight down, but come down straight. There's a pretty good chance that nobody is standing directly under it, but if you allow the attitude to get that bad, then open it up to stop the fall, it shoots off in some unknown direction.

There's also a really bad yaw right at the end too. I wonder what it was doing there...
 

dolby

Needs more bacon!
If one of the motors stopped shouldn't the copter start spinning instead as shown in the new 5.14 firmware video? Unless hes not running 5.14.


  • Attitude is controllable when one power output of X6 multi-motor is failed

http://www.youtube.com/watch?v=cNdzBRNNkAw
 
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jffry7

aka TruckBasher
Japp its was all purchased about 2 weeks ago. V4 ESCs V2 or whatever MC etc. The centerplate was actually different than mine. The lock downs for the arms were more robust and had little fins on them.


My S800 was bought about the same time well close to 4 weeks ago but this will mean its the latest batch. V4 ESC. I noticed when I opened up the motor mounting that the power/signal wires has been twisted or squeezed in side. Meaning the wires are only protected by wiring insulation. Thin coating, if this is true then heat + vibs might really cause short. Borris if you can ask your fried about what Denny was asking it will be good. I know it must be send to DJI immediately but if we can check ourselves what happen on those 6 motors/esc it might give a slight idea what happen. I doubt DJI will give the reason behind unless they already know it. I am not saying DJI is ignoring it, its just how it is I guess.

Edit: But then again, motors have close to same wire om windings and they are abused to same heat and vibes but they survive...unless they are loose inside the arms
 
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