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Old Jan 04, 2012, 08:49 PM
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Originally Posted by Z06 Tony View Post
Took my Y6 out for the maiden flight and after 1-2 mins it just pitched back and I could not land it. It was low so only prop damage. I only had a single 3300mAh batt so figured it was low bat but never checked it. Just put 2 fresh 3300mAh batts in it the 2nd time. Then I flew it 1-2 mins and it seemed fine so I took it higher and used GPS lock and in less than a min it pitched back and crashed. I built this Y6 with a diff Wookong-M on it and flew like 20 flights flawlessly and then put this new Wookong on it so I dont think it is motors/ESC. Plus if u watch vid it is not like any of the motors stop or it would just flip back. Checked batts and they were not low at all. Anyone have any ideas?

http://www.youtube.com/watch?v=wmDlzOiJvb0
Tony I did not see one but did you have a VTX onboard? I have found that my 900mhz 500mw VTX was screwing up my Position Hold even though I had NO blinking RED light indicating a GPS Lock. I wonder if that could be your issue?
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Old Jan 04, 2012, 09:02 PM
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Canada, ON, Toronto
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About to Maiden, need some reassurance

Hey there, I finally finished my build - Jakub's 450 frame with some slight modifications to fit the DJI WKm. I'll upload pics and specifics later.

Please tell me if I missed anything obvious:

Motors spin the right way.
ESCs are programmed NiMh, low cutoff, no brake, high timing and throttle limits set.
Found approximate CoG and entered values as per manual.
3 pos switch set to GPS / Atti / Failsafe (FS- RTH)
DJI software was configured and written to FC.
I haven't calibrated the compass yet - too cold today so that is to be done.
Props are balanced, but not the motors.
Put it in window and it acquired Sats in 3-5 minutes. Single blue flash in GPS mode.

Anything else? - so many wires, configuration, balancing that my brain is now full.

My plan is now to get to an open space, wait for sat acq, and give some throttle to make sure it isn't going to flip. If it looks good get her in the air and have fun. So if anyone has some last minute pointers or recommendations please speak up!


Jason
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Old Jan 04, 2012, 09:08 PM
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Originally Posted by Tahoe Ed View Post
I have the 900mHz DJI Data Link that is 1W. I have not had a chance to fly it yet. I wouldn't think that DJI would have a piece that interferes with its own systems. I wonder if it is the nature of the vTx signal. You can also try 5.8gHz. That is what I am using.
This problem is very weird, I would think if I had a Lock with NO Blinking Light it would hold position.
I turned the VTX off and the problem went away, then I tunned the Disturb Gain and she just sits there with no toilet bowling.
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Old Jan 04, 2012, 09:10 PM
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Quote:
Originally Posted by schnellschnell View Post
Hey there, I finally finished my build - Jakub's 450 frame with some slight modifications to fit the DJI WKm. I'll upload pics and specifics later.

Please tell me if I missed anything obvious:

Motors spin the right way.
ESCs are programmed NiMh, low cutoff, no brake, high timing and throttle limits set.
Found approximate CoG and entered values as per manual.
3 pos switch set to GPS / Atti / Failsafe (FS- RTH)
DJI software was configured and written to FC.
I haven't calibrated the compass yet - too cold today so that is to be done.
Props are balanced, but not the motors.
Put it in window and it acquired Sats in 3-5 minutes. Single blue flash in GPS mode.

Anything else? - so many wires, configuration, balancing that my brain is now full.

My plan is now to get to an open space, wait for sat acq, and give some throttle to make sure it isn't going to flip. If it looks good get her in the air and have fun. So if anyone has some last minute pointers or recommendations please speak up!


Jason
You want Manual Mode instead of Fail Safe on the 3 position switch. I use a Programmable mix with another switch to trigger RTH.
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Old Jan 04, 2012, 09:23 PM
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Calgary Canada
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you can either separate the two, put a filter on the video TX or go with 1.3 ghz.

Quote:
Originally Posted by Tarro View Post
I found the problem I was having with the GPS Position Hold. I have a 500mw 900mhz VTX onboard and it was messing up the Position Hold badly. I could get a GPS Lock with NO blinking Red light, but when I engadged the Position Hold the copter would wander all over the place. I disconnected the VTX and she holds nicely but still toilet bowled a bit. I adjusted the Disturb Gain and found the sweet spot at 80%, now she just sits there. It is 9:30pm 27 degrees F and no wind so I am going to have to see how she behaves in the wind. Tomorrow it is suppose to blow about 14mph, that should be a good test.
Now I have to figure out away to get a video feed without it messing with the GPS. Any ideas?
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Old Jan 04, 2012, 09:26 PM
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data and video streams are quite differnt I have found.... data does not tend to mess with gps as much... small quick packets are sent and received.

I have had to unplug my 900mhz data modems so that I can get gps lock on my other uav systems... then plug it in again once lock is attained but I never lose lock again...

900mhz and gps = bad news no matter how you look at it.... if you don't want long range flying I would stick with the 2.4 data modem... however this may cause issue with your radio depending on type... FASST seems to be the most immune to other 2.4 devices including 2.4 video...

all just my humble opinion of course

Steve


Quote:
Originally Posted by Tahoe Ed View Post
I have the 900mHz DJI Data Link that is 1W. I have not had a chance to fly it yet. I wouldn't think that DJI would have a piece that interferes with its own systems. I wonder if it is the nature of the vTx signal. You can also try 5.8gHz. That is what I am using.
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Old Jan 04, 2012, 09:34 PM
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I know I am not supposed to compare to MK but if there is no wind then the gps gains need to be reduced to stop toilet bowling with the MK... more wind meant more gps gains...

so what you are saying here rings true for sure.. but I really wish someone would listen over there and give us the ability to remotly adjust ALL PARAMETERS from the RC TX... then I can leave the gps gains on a slider just like I do with MK.

Good you have it mostly sorted now!

Quote:
Originally Posted by Tarro View Post
This problem is very weird, I would think if I had a Lock with NO Blinking Light it would hold position.
I turned the VTX off and the problem went away, then I tunned the Disturb Gain and she just sits there with no toilet bowling.
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Old Jan 04, 2012, 09:50 PM
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Originally Posted by saabguyspg View Post
you can either separate the two, put a filter on the video TX or go with 1.3 ghz.
I have a Low Pass filter on it now, there is not alot of room to separate the 2. I am going to try a 1.3ghz VTX I have tomorrow. This is very strange, isn't it?
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Old Jan 04, 2012, 09:54 PM
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Originally Posted by saabguyspg View Post
I know I am not supposed to compare to MK but if there is no wind then the gps gains need to be reduced to stop toilet bowling with the MK... more wind meant more gps gains...

so what you are saying here rings true for sure.. but I really wish someone would listen over there and give us the ability to remotly adjust ALL PARAMETERS from the RC TX... then I can leave the gps gains on a slider just like I do with MK.

Good you have it mostly sorted now!
I agree, if I had a choice of which Gain to control from the ground I think it would be the Disturb Gain. The Basic and Atti gains can be constant in the wind but the Disturb Gain would best stop the Toilet bowling when needed.
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Old Jan 04, 2012, 10:00 PM
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yes and no... if it gets the required number of sats to stop blinking after that it could possibly be dropping and picking up sat's but you don't ever see that... this could have an effect... also the signal strenth makes a big difference too... if you add a ground plane you will increase your signal strength 30% easily and shield out all other RF at the same time....

I found with MK if I had poor signal strength I would have poor position hold.... with my ground plane I had rock solid hold and instant sat fix.

have you tried a different channel on your 900mhz video TX? it's not a good fix however but it may produce some interesting tests.... 1.3 is pretty good at keeping away from the gps band... 2.4 is better.... I guess you could also go 5.8

Good luck and thanks for the tests with the disturb gain.

Steve

Quote:
Originally Posted by Tarro View Post
I have a Low Pass filter on it now, there is not alot of room to separate the 2. I am going to try a 1.3ghz VTX I have tomorrow. This is very strange, isn't it?
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Old Jan 04, 2012, 10:06 PM
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Originally Posted by saabguyspg View Post
yes and no... if it gets the required number of sats to stop blinking after that it could possibly be dropping and picking up sat's but you don't ever see that... this could have an effect... also the signal strenth makes a big difference too... if you add a ground plane you will increase your signal strength 30% easily and shield out all other RF at the same time....

I found with MK if I had poor signal strength I would have poor position hold.... with my ground plane I had rock solid hold and instant sat fix.

have you tried a different channel on your 900mhz video TX? it's not a good fix however but it may produce some interesting tests.... 1.3 is pretty good at keeping away from the gps band... 2.4 is better.... I guess you could also go 5.8

Good luck and thanks for the tests with the disturb gain.

Steve
Can I make a Ground Plane for the WKM GPS?
I am going to do more testing tomorrow in 10 plus MPH winds.
Thanks
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Old Jan 04, 2012, 10:22 PM
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Originally Posted by milo12 View Post
That is the best stability performance I have seen.

I hope the price isn't $2500, but I would pay half of that today. $1250 is very reasonable for what I see on those videos. It performs far better than systems that cost almost $1,000.
From this link,it only cost $1099 Free Shipping

http://www.goodluckbuy.com/dji-wooko...opter-fpv.html
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Old Jan 04, 2012, 10:35 PM
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even just putting a thin sheet of copper under the gps will act as a ground plane... yes theroetically it should be connected to the ground on the gps.. but it's not worth opening up the compass / gps for that.... make it about 4" square and see what happens.

also make sure you don't have any high power lines running near your compass (lines from the esc's to the motors don't seem to cause issue from my experiance but the power lines to the esc will)...

Steve

Quote:
Originally Posted by Tarro View Post
Can I make a Ground Plane for the WKM GPS?
I am going to do more testing tomorrow in 10 plus MPH winds.
Thanks
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Old Jan 04, 2012, 10:36 PM
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buy from a reputable dealer near where you live... there are lots posting on here... you are going to want the support if something goes wrong.

Steve

Quote:
Originally Posted by Chris Delfino View Post
From this link,it only cost $1099 including shipping

http://www.goodluckbuy.com/dji-wooko...opter-fpv.html
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Old Jan 04, 2012, 11:09 PM
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Originally Posted by saabguyspg View Post
buy from a reputable dealer near where you live... there are lots posting on here... you are going to want the support if something goes wrong.

Steve
If you are in the states I recommend Gary Travis at http://aerialtechsystems.com/ He knows the system inside and out -

MM
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