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sriramgbhagwat / arducopter

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One servo turning slower than the others #390

Closed GoogleCodeExporter closed 8 years ago

GoogleCodeExporter commented 8 years ago 
Arducoper ACM
What steps will reproduce the problem?
1. Open the Mission Planner software and connect to the board. In the Flight 
Data view go to the Status tab.
2. Throttle up on radio (stays level for a little bit)

What is the expected output? What do you see instead?

All motors should be turning at about the same speed (channel out 1-4 should be 
relatively close in numbers).  Instead channel 1 and 3 are close but channel 2 
is significantly lower than 4 (back right wing dips with my X frame).  

*NTOE* When I talk about channel in this context I am referring to the variable 
name ch#out which describes the servo speed.

What version of the product are you using? On what operating system?

Latest version on Windows 7.

Please provide any additional information below.

The ESC controlling this motor is also powering the Arduino boards on the 
copter.

Original issue reported on code.google.com by MRP2...@gmail.com on 14 Mar 2012 at 1:07

GoogleCodeExporter commented 8 years ago 
MRP,
     thanks for reporting this.

     I guess you've run the level command from the mission planner?

     is the HUD display on the flight data screen in the mission planner also level or does it show you leaning forward?

Original comment by rmackay...@gmail.com on 14 Mar 2012 at 1:44

GoogleCodeExporter commented 8 years ago 
I have run the level command on the Mission Planner, I will try again this 
evening though. 

When paying attention to the HUD display it usually shows that it is not 
completely level. Our flight is maybe only 5 to 10 degrees off from level so 
its hard to tell on the Hudd when it bounces around. 

Other information, the servos will all spin at the same speed till I hit about 
80% throttle which is about when the Quadcopter takes off.

Original comment by MRP2...@gmail.com on 14 Mar 2012 at 2:44

GoogleCodeExporter commented 8 years ago 
MRP2189,
    ok, so it sounds like your quad knows that it's not level which is good.  That rules out vibration problems and means it's either a hardware problem or a control logic problem.
    Needing to put the throttle to 80% just to take off makes me think your quad is under powered for all you're trying to lift.  I suspect if you increase your stabilize I and IMAX values the problem might go away.  If that works though it's not really a great solution because it means that some motors are much weaker than others.  Can you give that a try?

Original comment by rmackay...@gmail.com on 15 Mar 2012 at 11:47

GoogleCodeExporter commented 8 years ago 
it is normal for motors to not be spinning in sync. That's how quads turn or 
Yaw. Your yaw error may be large and you aren't away of it, even if the quad 
has not been turned.
Jason

Original comment by jasonshort on 15 Mar 2012 at 3:58

GoogleCodeExporter commented 8 years ago 
I did some more testing this evening. The reason it is about 80% throttle is 
because i have a 5000mah battery on it which is really heavy. I tried to 
increase the I and the IMAX stabilization for both pitch and roll and it didn't 
look like it changed anything.

I looked at some of the voltages, the signal going into the ESC's from the 
board are about the same on all the wings. The voltage between the ESC and the 
motor on the wing that is dipped is about 7.56 V while the voltage on the other 
wings is about 8.11 volts? Does this mean that my ESC is not working correctly? 

I have the Quadcopter tethered to a table so that it can only lift off about 5 
inches off the ground. The Quadcopter bounces/wobbles around quite a bit and it 
moves around the center point in a circular fashion. 

I also removed the blades and wanted to see how bad the vibration was on each 
wing. On one of the wings (not the bad one) there is no vibration but on all 
the other three have a medium vibration. I am not sure if there is suppose to 
be absolutely no vibration in the wings. 

Thanks for all your help on this.

Original comment by MRP2...@gmail.com on 16 Mar 2012 at 1:41

GoogleCodeExporter commented 8 years ago 
I guess you can't try a lighter battery?  I think you're just reaching the 
limits of what the engines can carry, in this bigger isn't better!

Original comment by rmackay...@gmail.com on 16 Mar 2012 at 11:28

GoogleCodeExporter commented 8 years ago

Original comment by rmackay...@gmail.com on 10 Apr 2012 at 2:31