Replies to This Discussion

DeveloperPermalink Reply by jasonshort on January 22, 2012 at 12:52pm

Did you run the level command? Does it stabilize correctly in your hand when you give it throttle?

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Permalink Reply by Serplat on January 22, 2012 at 12:54pm

Yes, I ran the level command.

How exactly am I supposed to do that in my hand?  With the propellers on?

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Permalink Reply by James on January 23, 2012 at 1:12am

its a bit hairy at first, but you get used to it :D

put the transmitter down on the ground close to the quad/hexa/whatever, make sure youre in STABILIZE flight mode, get a firm grip on the top of it and apply enough throttle to _almost_ take off.  now you can lift it slightly off the ground and feel if it is stabilizing correctly - you should feel it resist any attempt to tilt forward/backward or left/right.

its also a good way to ensure all RC channels are in the correct orientation, just a slight touch on the roll and pitch stick will be felt - and should be in the same direction as the command from the transmitter.

its worth doing this before every flight, just to make sure everything is working.

james

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Permalink Reply by Jan Schermer on January 23, 2012 at 2:34pm

And always wear sunglasses when doing that, or get plastic protective glasses - sooner or later you'll forget to fasten a prop adapter or give full throttle for the first time and it will fly off in random direction...

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Permalink Reply by Serplat on January 23, 2012 at 5:44pm

I've run the hand test and it tries to stabilize correctly in my hand when I increase the throttle.  However, it still takes off in a not-so-straight direction.

Is it unreasonable of me to be expecting a fairly straight-up takeoff?  It keeps shooting out in one direction or the other, before it is even a foot off of the ground.

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Permalink Reply by Jan Schermer on January 23, 2012 at 10:29pm

are you taking of in Stabilise mode? This is what current ACRO does to me (but in my case it tilts about 10 degs front). It wants to stay there no matter how I correct, but may be cause by my setup...

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Permalink Reply by wraith on January 22, 2012 at 4:20pm

u could try the auto level feature, ive become a fan of that feature

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Permalink Reply by Grips on January 23, 2012 at 6:07pm

Do you have a photo of your setup? Is it horrible out of balance somehow? Do you have anything added extra?

Have you checked the trims and sub-trims on your radio to ensure they are all in the middle?

Have you tested your compass in the terminal screen to ensure it is working properly?

Is there a chance a landing gear leg may be hooked in the ground/grass and causing it to pitch backwards?

Is there some sort of a mix setup in your radio that is applying elevon while you push the throttle up? And a sub-note, are you possibly using a heli mode where cyclic and throttle are operating in unison?

How much wind are you flying in?

If you correct the pitch by applying forward elevon, will it hover?

It should take off going straight up from my experience. Don't expect it to take off straight up like a rocket though,  in a perpendicular line from the launch site.

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DistributorPermalink Reply by Dany Thivierge on January 23, 2012 at 6:01pm

did you do basic things such as making sure the battery weight is not changing the center of gravity? 

Put some velcro on the battery and frame battery holder once you find you perfect COG point that way the battery will not move and it will not affect the quad. But I really think a nice in flight auto level is the way to go... something must not be perfectly square in your frame/motor so this will teach the APM to know what is "straight and level" and it will fly way better. 

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Permalink Reply by Ellison Chan on January 23, 2012 at 6:11pm

Heh.  Have look at the blogI just posted. "

Due to ground effect from the backwash, it's always a little squirely on lift off.  You have to correct for that.  Also if you're not flying the 3DR frame, the P values may have to be adjusted.  As mention in my block my frame is smaller than the 3DR frame, so I dialed back the P values to 80%.

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