Hey all,

 

I'm having some real problems getting my new guy to take off.  This is everything from the jDrones kit (except in the Xaircraft hexa frame), 850Kv motors, 20 Amp ESC's, hexa PDB, 10x45 props, APM1.0.  On takeoff, the copter wants to move to the right, and will not lift (at least at the throttle percentage I'm willing to give it).  At higher throttle, the motors start to vibrate to what seems like a dangerous extent.  This is what I believe is the main problem, but I'm having a lot of trouble figuring out what is going on.  I was hoping the community might be able to chip in on the issue and help me get off the ground.  

 

Here is a link to the above video of the problem:

http://youtu.be/_nj9vihERHU

 

Thanks in advance for any help!

 

Blaine Hoyt

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Brain, 

Make sure your orientation is set correctly, + or X, 

Make sure your motors are setup correctly and do the calibration routine form the wiki.

Then do hand test to make sure it is all working ok. Hold it, give mid throttle and try to tip the copter. It should want to stay horizontal.

Also, turn the I terms stabilize_I and rate_I to 0.

Jason

Ok, I'm about to try to change the I settings, I went through the troubleshooting guide in the wiki and covered everything in the section on wobbling on takeoff (everything checked out).

edit: stabilize and rate I terms were already set to 0.

I was messing around with the settings, and I changed the copter from + to X...  It still has wacky results, but seems to get much more thrust and feels like it wants to take off more.  The problem is, my board is aligned with the front motor (which I believe is the '+' configuration)...  Not sure what this means, but maybe it could help someone else.

OK, so I switched modes to hexa x, and rotated my APM so 3 and 7 are at my front left and front right respectively.  It actually wants to lift off the ground, and does a little bit, but not before it wobbles to the point where it crashes.  Motors command has been run, all motors are in proper locations, have the correct rotation, and the right pushers/pullers.  I'ts a step in the right direction I can tell, but still not fixed.

Blaine

If your motors are vibrating badly, this can upset the gyros.  It's a bit hard to tell from the video, but if the spinners are a blur when the motor is running, then there's probably a need for balancing.  You can also tell by holding the quad as you raise the throttle. 

Check your prop and motor balance.  Also check you have the right diameter inserts in the props (if they have them) and that the props are centred on the spinners.

Dave,

The inserts are the right size for the props, and a hand test does show some vibration (that I don't think should be there).  Visually you can tell that something seems unbalanced, but these are new props, new motors, everything is tightened down, etc.  I'm just not sure what the next step is in getting this thing working.

Blaine

 

Here are two videos of it in X mode:

 

I didn't want to lift it any more or it would have gone completely out of control.  Just hoping this might help someone help me out!

 

Blaine

Hmm, doesn't really look like there's a real problem to me...  While in flight the hexa seems reasonably stable considering it's in ground effect all the time.  It only flips over after you let it hit the ground.

Try doing some more hopping and getting a bit more confident to let it rise a little higher and/or fly a little longer.  Try not to be too stressy on the sticks.

Also, do it outside where you have plenty of room.

The issue is, my MK Hexa on take-off goes straight up, no wobbles.  This feels completely different (and might I add dangerous).  I fly the MikroKopter indoors in the same room, with no problems or worries so far.  Should I just not expect the same level of quality from this product?

I am also not ruling out dumb user error :)

Maybe something with the PID values?

Blaine

Just saw this now - take a look at my other post. You need to tune it a little, and it might never be as "perfect" (every controller is different, some regard for example Multiwii as superstable, for me it's unflyable, YMMV :-)). Hopping on the ground does no good...

Not sure if this helps or not (newbie here) but I have heard that vibrations can sometimes be sorted out by taking off all the motors (or maybe just the props) and spinning up each motor or motor/prop assembly individually.  One site shows an iphone or Android phone with a seismometer used to balance motors by themselves using tie wraps and tape.  It is a time consuming process but once you are done you can be assured that at least the motors/props are out of the vibration equation.

Best of luck

Paul

You can achieve the same watching Sensor data in Planner - also by using a different sensor (phone placed somewhere) you can see completely different vibrations than those that reach the real sensors.

But yeah, checking props and motors for balance is not a bad idea - but I went through a bunch of very different prop/motor combinations and never had to balance anything - and those were $8 motors and $4 props from china we're talking about...

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