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Old Dec 14, 2011, 01:47 AM
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Another thought: The DJI drawing should be sketched as in the Math world (with Z- axis pointing UP = Positive values above the [0,00] point) BUT... this X, Y, Z drawing should have its center ([0,00]) in the IMU and a second X, Y, Z drawing with its center point ([0,00]) in the center of the GPS...

Only then, if the IMU or GPS are (as in most of our Multis, I guess) are ABOVE he CoG, the values for the Z- axis are NEGATIVE, as DJI proposes.

My point is that their drawing in the Assitant is confusing and mathematical NOT logical...
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Old Dec 14, 2011, 03:12 AM
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Martinski, just watch out. My first WMK build had the IMU pretty high over the CG. At the beginning I understood the CG IMU being over as a positive and not negative number. Resulting in me adding a positive number for the z-axis. This resulted in a take off flip due to the combination of wrong gains also. I don't want to get into a discussion whats wrong or right, just telling you if you have some expensive props on and start testing just watch out.

Boris
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Old Dec 14, 2011, 03:17 AM
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I fully agree with you - will also be very careful and start again with a NEGATIVE Z - value but my point of discussion was simply the confusing layout of the drawing!

Also in their text they state your point! Just check my answer above... this discussion should be unnecessary if the X-, Y-, Z- axis should have their starting point ([0,0,0]) respectively in the IMU and in the GPS (also one such drawing for each).
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Old Dec 14, 2011, 03:39 AM
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Originally Posted by Martinski View Post
I fully agree with you - will also be very careful and start again with a NEGATIVE Z - value but my point of discussion was simply the confusing layout of the drawing!

Also in their text they state your point! Just check my answer above... this discussion should be unnecessary if the X-, Y-, Z- axis should have their starting point ([0,0,0]) respectively in the IMU and in the GPS (also one such drawing for each).
japp i agree it is confusing and it might be the typical situation were developers were involved in manual and trying to explain something that is clear to them from the beginning. Resulting in a complex confusing explanation. Have seen this several times in my past IT times
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Old Dec 14, 2011, 03:47 AM
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Does somebody else has tested the datalink yet ? I would like to see if he has the same problem on the google earth map localisation...
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Old Dec 14, 2011, 04:15 AM
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Does somebody else has tested the datalink yet ? I would like to see if he has the same problem on the google earth map localisation...


Are you talking about this image .... bird to Red X location?

The 1M is altitude .... did you use altitude offset? click Set altitude offset, "ok" recommended off set ...... try this.
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Old Dec 14, 2011, 05:15 AM
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Are you talking about this image .... bird to Red X location?

The 1M is altitude .... did you use altitude offset? click Set altitude offset, "ok" recommended off set ...... try this.
The Red Arrow is right above the Red Cross, but not in front of it. The arrow is in the air as the offset was not done.
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Old Dec 14, 2011, 05:30 AM
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Originally Posted by sidneyw View Post

Are you talking about this image .... bird to Red X location?

The 1M is altitude .... did you use altitude offset? click Set altitude offset, "ok" recommended off set ...... try this.
Thanks... I will try !
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Old Dec 14, 2011, 08:46 AM
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I think I'm doing it correctly but the way I thought about the Z was how I would move the unit to the COG.

For example, the GPS is above the COG so I would have to 'bring it down' (subtract) to get it on the COG...therefore I have a negative number.

If the unit were below the COG then I would have to 'push it up' (add) to get it on the COG...therefore I would have a positive number.
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Old Dec 14, 2011, 08:57 AM
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Sydney,
Is progress being made on the camera mount servo twitches issue? If so, can you elaborate? Thanks.
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Old Dec 14, 2011, 11:22 AM
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Originally Posted by 500Driver View Post
I think I'm doing it correctly but the way I thought about the Z was how I would move the unit to the COG.

For example, the GPS is above the COG so I would have to 'bring it down' (subtract) to get it on the COG...therefore I have a negative number.

If the unit were below the COG then I would have to 'push it up' (add) to get it on the COG...therefore I would have a positive number.
Alright! May agree wih your point of view... BUT please, in the same spirit of thought, explain when the IMU and/or GPS are to the LEFT or to the RIGHT of the CoG... Substract or add...!!!????

Here they rely on the classical X-Y mathematical scheme where LEFT and BELOW the initial point ([0,0,0]) = NEGATIVE while to the RIGHT and ABOVE the initial point ([0,0,0]) = POSITIVE...

I guess somebody just missed the Z- axis and reversed here the classical order!

Anyway - many thanks for the idea! M
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Old Dec 14, 2011, 11:38 AM
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Good news coming for MR specific ESCs:
http://www.diydrones.com/profiles/bl...uad-esc32-v1r5

40A or more and 5S capable, that should fit the bill for almost every MR, just wish it was 6S capable but baby steps...
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Old Dec 14, 2011, 11:54 AM
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Originally Posted by TimIndy View Post
Sydney,
Is progress being made on the camera mount servo twitches issue? If so, can you elaborate? Thanks.
I had to face this problem, too.
Got the white flashes and the twiching roll servo for the first time after using 4.2 for some time. The copter also acts very strange as if there was a problem with the gyro. That made me think if the unit has a defect that appears now&then?
One lipo it flies fine, next lipo (same as first one, properly loaded and balanced) it acts like mad: wants to flip right after taking off.

After flashing the latest 4.22 the problem seems to be gone ... for now ... but have only 1 flight so far - until white LED flashed again.

Unfortunately there's now way to check what the gyro is doing since there's no artificial horizon in the GUI or another output to control the values.

I guess the gyro for some reason thinks it's moving - thus the gimbal twitching.
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Old Dec 14, 2011, 01:36 PM
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Trenton, NJ
Joined May 2008
789 Posts
ESC Question for WK-M

Hello,

Can someone tell me if the ESC at this link is one of the modified ones with the higher refresh rate that will work well with the WK-M. http://www.quadroufo.com/product_inf...vus2fc9ek3acr0 .

If not, then can someone please post a link to ones in the 20 to 30 amp range that are modified with a higher refresh rate that will work well.

I sent an email to HobbyWing about this subject, specifically inquiring about a report that someone there by the name of Ken may load the fast PWM SimonK firmware into the ESCís to make them perform much quicker, but have received no response as of yet.

Thank you,
Tom
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Old Dec 14, 2011, 02:09 PM
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Just joined the Wookong M Craze - Thanks Gary at Aerial Tech Services - His knowledge on the DJI Wookong is just amazing -

MM
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