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Old Sep 17, 2012, 02:53 PM
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Please Help!!
I am having a problem with the idle speed.
3 of the motors marked with X start faster than the oder 3 marked with O.
I already tried all idle speed positions and i always have the same problem.
Everything was working fine before, no changes were made to the setup.
I only tried this on atti and gps mode and watt happens is wen i am at middle throttle and hovering, i have sudden changes in motors speed and the s-800 loses altitude. It looks like is losing power.
I have tried with new and old batteries.
I also noticed that i started to have 2 and 3 withe flashes when i am flying, never had them before. Props and motors are calibrated.
Can any one help me solving this problem.
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Old Sep 17, 2012, 02:59 PM
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@Infante

Tell us about your set up. How far is your receiver from the IMU? Have you tried to swap arms? Just a few questions.
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Old Sep 17, 2012, 03:38 PM
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Quote:
Originally Posted by Tahoe Ed View Post
@Infante

Tell us about your set up. How far is your receiver from the IMU? Have you tried to swap arms? Just a few questions.
Hi.
I didnīt swap the arms, i mean, the problem is from the diference of speed from clock and counter clock rotation motors.
The IMU is far from the transmitter, i never had this issue before.
I am using 2x6s 4000mah and sometimes 2x6s 4500mah.
The radio is the Graupner MX-20.
Here are some pics.
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Old Sep 17, 2012, 03:48 PM
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Austria, Wien, Vienna
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Quote:
Originally Posted by Infante View Post
Hi.
I didnīt swap the arms, i mean, the problem is from the diference of speed from clock and counter clock rotation motors.
The IMU is far from the transmitter, i never had this issue before.
I am using 2x6s 4000mah and sometimes 2x6s 4500mah.
The radio is the Graupner MX-20.
Here are some pics.
I wouldn't worry to much about the different idle speed at start up. Mine does that occasionally but once at take off or holding height there are no problems. If there would be a speed difference between the O and X arms things would result in a uncontrollable yaw etc. Don't think that the idle speed has anything to do with your setup not holding the altitude.

How many times has this happened now ? Once with one lipo, several times on the same day with different lipos ?
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Old Sep 17, 2012, 03:53 PM
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The little hole in the IMU that lets the air in for the Baro sensor lie to the inside of the IMU when mounted forward facing on the S800. Could it be that you have something blocking that hole ? A cable some component etc.

Boris
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Old Sep 17, 2012, 03:53 PM
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Moscow
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Originally Posted by Infante View Post
Please Help!!
I am having a problem with the idle speed.
3 of the motors marked with X start faster than the oder 3 marked with O.
this is wkm problem, not s800.
idle pulses are different for cw and ccw outputs.
long story short, recalibrate esc's with some digital servo tester, play with low pulse value.

Quote:
Originally Posted by BorisSA View Post
Mine does that occasionally but once at take off or holding height there are no problems.
thats also true

cheers
dimitri
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Old Sep 17, 2012, 03:58 PM
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has similar problems once with an older build CS8 WKM. In my case the problem was that the outer pressure influenced the inner climate of my apartment and the heating was on full blast etc.

In this video i never changed the throttle input but the CS8 just landed.

WKM Alt Hold no working at all anymore. (1 min 3 sec)


You don't have a data link by any chance and can readout if the height drops while having the bird stading on the ground ? Could indicate that there is a problem with the baro sensor
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Old Sep 17, 2012, 04:00 PM
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Quote:
Originally Posted by mitmit View Post
this is wkm problem, not s800.
idle pulses are different for cw and ccw outputs.
long story short, recalibrate esc's with some digital servo tester, play with low pulse value.


thats also true

cheers
dimitri
Hmmm can you calibrate the S800 ESCs ? Never tried it ! Shouldn't they have a fixed range ?

Boris
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Old Sep 17, 2012, 04:10 PM
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Quote:
Originally Posted by BorisSA View Post
I wouldn't worry to much about the different idle speed at start up. Mine does that occasionally but once at take off or holding height there are no problems. If there would be a speed difference between the O and X arms things would result in a uncontrollable yaw etc. Don't think that the idle speed has anything to do with your setup not holding the altitude.

How many times has this happened now ? Once with one lipo, several times on the same day with different lipos ?
Hi Boris!
This normally happens when i use my 2X6S 4500mah 35-70c Nanotech
I dont remember having this problem when i am flying with 2X6s 4000mah 30c turnigy.
The nano are a little bit heavier but they are new, and i also have withe flashes, never had them before.
I must also say that the last time i tried to fly it was windy.
The IMU is free from dust or any thing that could block the barometric sensor.
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Last edited by Infante; Sep 17, 2012 at 04:17 PM.
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Old Sep 17, 2012, 04:17 PM
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Portugal, Lisboa, Sintra
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Quote:
Originally Posted by mitmit View Post
this is wkm problem, not s800.
idle pulses are different for cw and ccw outputs.
long story short, recalibrate esc's with some digital servo tester, play with low pulse value.


thats also true

cheers
dimitri
Hi.
I dont have a servo tester, but even if i had i didn't knew how to do it.
is that really necessary?
cheers
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Old Sep 17, 2012, 04:17 PM
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Quote:
Originally Posted by BorisSA View Post
Hmmm can you calibrate the S800 ESCs ? Never tried it ! Shouldn't they have a fixed range ?

Boris
They are preprogramed as are the rest of the DJI escs. No programing necessary.
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Old Sep 17, 2012, 04:21 PM
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Originally Posted by Infante View Post
Hi.
I dont have a servo tester, but even if i had i didn't knew how to do it.
is that really necessary?
cheers
Infante don't worry about it like Tahoe Ed just stated the s800 escs are just like the DJI ESCs you can't calibrate them !
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Old Sep 17, 2012, 04:22 PM
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What changed when the white flashes started?
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Old Sep 17, 2012, 04:31 PM
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Quote:
Originally Posted by BorisSA View Post
Hmmm can you calibrate the S800 ESCs ? Never tried it ! Shouldn't they have a fixed range ?
hmm, probably you are right Boris)
did not try that with s800.
it happened once with wkm on other frame, but in my case it behaved a bit different - cw motors did not start at all while ссw were ok at idle. playing with low pulse width did helped..

cheers
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Last edited by mitmit; Sep 17, 2012 at 04:37 PM.
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Old Sep 17, 2012, 04:34 PM
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Quote:
Originally Posted by Tahoe Ed View Post
What changed when the white flashes started?
Very unstable beaver and lost of power, losing altitude.
This normally happens when the throttle stick is near the center position.
This might be a dum question but, with the graupner MX-20, the traveling of channel 1, which is throttle, goes from -100 to 100, shouldn't it be 0 to 100?
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