3D Robotics Comment by Chris Anderson on December 28, 2011 at 5:58pm

I think the boards have changed since those instructions. Might be worth trying to swap the front and back motors. I've pinged the 3DR team to see if the instructions need to be updated. 

3D Robotics Comment by Alan Sanchez on December 28, 2011 at 6:16pm

Hey Jon! Glad to see you got it flying. About the reversed pitch, I usually have to flip both my pitch and yaw in the stock settings for my spektrum radio. So if you flip the pitch you should be all good. Instructions for the PDB should not have changed, but ill look them over.

It seems that its doing some agressive recovering, tuning can help but not sure if maybe it was pilot error like you said and you were correcting strongly. Flying the quad is all tiny smooth inputs.

About it flipping, I have never had anything like that happen on hard landings. But if you bring it by when you come visit we can take it for a spin. A tip for tomorrow when youre flying over grass, careful when the quad bounces on the ground (if it does), the legs sometimes get caught in the grass and will flip over the quad. If you feel that happening, just kill the throttle. Good luck tomorrow :)

Comment by BoBo Flight on December 28, 2011 at 7:35pm

You will have less vibrations with your motor prop setup which is good for video and some other things ... But I have seen those wobbles before ... It could be the pilot or partly the setup. You might want to try smaller props and change the pitch if this decrease in size gives you too little power. However you always give up something. Going smaller on the props will have its adverse affects as well on motor RPMs, reserve thrust, etc.

Safe crashing ... Er, I mean flying :).

Comment by Jeff Taylor on December 28, 2011 at 9:54pm

I second Alan's suggestion. Your PDB sounds fine or else it would be rolling constantly. Just reverse the RC channel and it will fly as you expect.

Comment by Jonathan M on December 29, 2011 at 12:07am

Thanks for the suggestions guys.  I will first try reversing the channel and seeing what happens.

I probably will try smaller props if I can't tune out the wobble, but I lose my efficiency and T/W advantages if I do.

Will report back tomorrow :)

Comment by Martin on December 29, 2011 at 5:09am

I have hexa with same motors.http://www.rcalbum.com/index.php?action=dtl&amode=&id=6313 First I used 10x4.7APC props with good results. A also flew with 12x3.8 APC and I had same problem with wobbling,  I think these props are too heavy and there is problem with fast reaction.One this prop is cca 17g heavy, instead of 11g for 10x4.7. My fried has on DT750 these props http://www.mejzlik.eu/multicopter-propellers/, he is very satisfied.

Comment by AS on December 29, 2011 at 6:01am

Hi Jonathan!!

About those flips after hard landings, I also have experienced something like that and damaged some motor shafts :\  I am also a noob in this quad flying stuff :D but I am learning..

I talked with a friend and he told me to not use the ESC's 5V, instead use a 5V BEC and to check my trim values. It worked for me!

How are you powering your APM?

Regards AS

Comment by Martin on December 31, 2011 at 4:07am

What's new? Have you managed woobling?

Comment by Jonathan M on December 31, 2011 at 10:57am

Martin,

I have had a few more tests since with varying success. Quad has completely flipped while trying to pitch or roll. I think this was a combo of bent motor mounts from previous crashes. Spent a few hours fixing and modifying after this including chopping my props to 11" to test the difference out. Quad flies well like this with some wobbles because of funky I believe. Last flight tested alt hold which works well and tried to tune pitch rate with ch6. This quad definitely like low values because as I incremented up the quad became unstable and flipped. Broke a prop and some spacers. Need to get more prior to my next test

Comment by Jonathan M on January 8, 2012 at 11:06pm

Update:

After some frustrating issues that I troubleshooted with help from a few of the guys at 3DR, I got a bit more flying/tuning time in with my quad.

****  SIDEBAR ****

The guys are 3DR rock!  Alan gave me a quick tour and showed me some of the new products they are working on (looking forward to 2012!).  Jordi helped my troubleshoot my APM, which turns out may have been a battery or soldering issue on the PDB (my fault).  Great visit and I get to add one more reason why I love living in San Diego :)

**** END SIDEBAR****

  I have tried a few different prop combinations since my first effort, and I believe that I have settled (at least for now) on 12x3.8 SF props "chopped" to 11" with the thought of unloading the motors a bit. I will most likely go back to 12x3.8 once i break my current setup.

I also added some foam to the bottom of the APM to damp some of the vibes.  Not really sure if it's helping at the moment.

Lowered the roll and pitch rates, which definitely seemed to ride some of the wobbles.  Still have wobbles in descent (up the Stab Pitch I term?)

Didn't get to try much of alt hold, but when I did use it, it seemed to work for a little while then would start to oscillate up and down.

Also, my quad tends to drift in stabilize mode, and it seems as if I am always trying to provide corrections.  Any suggestions to improve this or is this the norm?  You can kind of see this exhibited in the video.

(Don't mind the kids.. I corrected them earlier when they thought it was a plane :))

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