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Old Nov 13, 2012, 08:45 AM
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United Kingdom
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Quote:
Originally Posted by Steveis View Post
@Nexus21214 is the distance between each motor the same? They need to be and the centre of thrust needs to be the same as the centre of gravity. Check out this thread for a perfectly symmetrical and balanced T copter. With no self level it takes off like a rocket, flat as a pancake, when full throttle is instantly applied.

http://www.rcgroups.com/forums/showthread.php?t=1730781
Hi Steveis,
Yes the distance between the motors is the same. I seem to have pretty much solved that problem now by going into mixer settings and dropping the throttle value on Ch3 from 105 (default) to 30. I cant get the c of g perfect as itis part way down the tail boom, and cant put heavy lipos there in my design.

I now have a new problem with firming up the tail so it stays locked, but I think that will be down to careful Pi adjustments

Thanks for responding

Best Regards
Nex
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Old Nov 13, 2012, 08:48 AM
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Australia, NSW
Joined Sep 2006
138 Posts
I wonder if it's just a matter of trimming on the TX? Without SL mode it doesn't try to go forward that's all, but then the pitch is fully controlled by you so i guess it's not a good test. I'll try 1.2 as a test.

This is the output from the flash:

Flash the firmware from repository.
Flashing firmware from file.: C:\ft\tmp\KK2_1V5\kk2.hex

C:\ft\lib\avrdude\windows\avrdude.exe -C C:\ft\lib\avrdude\windows\avrdude.conf -p m324pa -P usb -c usbasp -B 8 -e -U flash:w:C:\ft\tmp\KK2_1V5\kk2.hex:i

avrdude.exe: set SCK frequency to 93750 Hz
avrdude.exe: warning: cannot set sck period. please check for usbasp firmware update.
avrdude.exe: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude.exe: Device signature = 0x1e9511
avrdude.exe: erasing chip
avrdude.exe: set SCK frequency to 93750 Hz
avrdude.exe: warning: cannot set sck period. please check for usbasp firmware update.
avrdude.exe: reading input file "C:\ft\tmp\KK2_1V5\kk2.hex"
avrdude.exe: writing flash (32112 bytes):

Writing | ################################################## | 100% 22.16s

avrdude.exe: 32112 bytes of flash written
avrdude.exe: verifying flash memory against C:\ft\tmp\KK2_1V5\kk2.hex:
avrdude.exe: load data flash data from input file C:\ft\tmp\KK2_1V5\kk2.hex:
avrdude.exe: input file C:\ft\tmp\KK2_1V5\kk2.hex contains 32112 bytes
avrdude.exe: reading on-chip flash data:

Reading | ################################################## | 100% 18.04s

avrdude.exe: verifying ...
avrdude.exe: 32112 bytes of flash verified

avrdude.exe done. Thank you.
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Old Nov 13, 2012, 09:38 AM
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Plainfield, IN
Joined Jun 2009
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Quote:
Originally Posted by stevenharting View Post
When on "stick":
a) If you arm the board with aileron all the way to the right it will turn SL on, and will remain on until b)

b) If you arm the board with aileron all the way left it will turn SL off, and will remain off until a)

When on "Aux" you use the fifth input on the board, the one closest to the buttons, and connect it to any available channel on the RX you choose (for example the one setup to the gear switch on the TX). Note that inputs are the pins connections on the left of the LCD, not the six pin connection at the bottom left which if for flashing firmwares

Great explanation, thank you!
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Old Nov 13, 2012, 11:05 AM
HeliHarry
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United States, OK, Tulsa
Joined Dec 2006
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Quote:
Originally Posted by harrym View Post
Why is it normal? One motor is faster than the others!
Could lead to abnormal attitude. Motors should be pretty close to being in synch.

<subaru4wd>
You forget that the KK2 is in control, not you.
If the board is not PERFECTLY level, it will try to compensate.
Control is relative Mr Spock!

If I calibrate the KK2 sitting on the table which is level, then raise the throttle just enough to get the motors spinning, all motors should maintain the same rpm because the KK2 thinks this is level. Am I wrong in my assumption?
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Old Nov 13, 2012, 11:23 AM
we dont NEED roads!
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United States, CA, Rocklin
Joined Aug 2012
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Yes you are wrong.

My V-tail does the same thing as your quad... if I lift the throttle just enough to get all 4 motors to spin, then don't touch the throttle. After a second, one motor always starts to spin faster than the others. Until it lifts off the ground, then all the motors catch up.

Just fly your quad, you will see, everything is just fine.
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Old Nov 13, 2012, 12:03 PM
HeliHarry
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United States, OK, Tulsa
Joined Dec 2006
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Quote:
Originally Posted by harrym View Post
Control is relative Mr Spock!
Ok! I'll take your word on that. Just seems odd that only the motor on M1 does this.
I'm a few days from the maiden flight. Will try with default settings then do some tweaking. With all the different setups it's hard to figure out what would be good to start with so I figure the 1.5 defaults is a good starting point.

Thanks!
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Old Nov 13, 2012, 12:06 PM
we dont NEED roads!
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United States, CA, Rocklin
Joined Aug 2012
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Quote:
Originally Posted by harrym View Post
Ok! I'll take your word on that. Just seems odd that only the motor on M1 does this.
I'm a few days from the maiden flight. Will try with default settings then do some tweaking. With all the different setups it's hard to figure out what would be good to start with so I figure the 1.5 defaults is a good starting point.

Thanks!
I have flown my 450mm quad, and my 710mm v-tail with factory default settings just fine. You will notice some oscillation and need to fine tune it... but it should fly.
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Old Nov 13, 2012, 02:03 PM
...just an earth bound misfit
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Joined Mar 2010
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Quote:
Originally Posted by brontide View Post
Does landing and rearming solve the problem and are you operating Nicole temperatures?
Temp was 13C (55F), rearming seemed to fix it. Winds were fairly steady 12 knots, so some forward pitch control input would be expected (to maintain position) if the KK was fighting to self-level, however the required input was slowly increasing to the point that it was almost full forward to land while not backing up.

When I let off the stick it would not stop at level, it was pitching fairly hard backwards.
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Old Nov 13, 2012, 02:10 PM
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Lynden, WA
Joined Nov 2000
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Quote:
Originally Posted by LegendLength View Post
I've read all of the thread since the 1.2 firmware release but still I can't fix my issue with self leveling, it drifts hard forward.

I did esc calibration, tried different PI values than the defaults, and just now I tried changing the accelerometer offset for both pitch and roll (under self level menu). That helped but after a few seconds it would want to go forward at 10 miles an hour.

This is all with 1.5 firmware and it flys great without self-level, but I really want self level to work for me.
Mine had a little side drift, watch this video about 3.5 min in it talks about how he cured it, and it worked for me, takes a few tries, but pretty simple.

Hobbyking KK2 board setup for gain and auto level with flight video (11 min 30 sec)
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Old Nov 13, 2012, 02:17 PM
Stop me before I build again!
United States, NY, Albany
Joined Sep 2012
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Yes, this is gyro bias from thermal changes.

The gyro return a value of how much turn in each plane, but the value is actually an analog reading. When you arm the KK samples the values to create a "0" reading from which all others are compared to. Greater than "0" is rotation in one direction, less than "0" is rotation in the other. The problem is that during temperature change ( and this affects some boards more than others ) the "0" point changes causing the board to think that it is constantly rotating ( vertigo ) and the KK tries to compensate.

Landing and rearming will create a new "0" point and correct the problem.
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Old Nov 13, 2012, 02:39 PM
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United States, FL, Palm Beach
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I've been hunting KK2.0 buddycodes for weeks now, but nothing, are they not eligible anymore?
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Old Nov 13, 2012, 02:46 PM
we dont NEED roads!
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United States, CA, Rocklin
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Originally Posted by viper522 View Post
I've been hunting KK2.0 buddycodes for weeks now, but nothing, are they not eligible anymore?
http://rcsearch.info/hobbyking/buddy...id=501#catalog

I dont see any either, unless you order one from the AUS warehouse. Not sure why they get buddy codes but we dont??
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Old Nov 13, 2012, 03:12 PM
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Quote:
Originally Posted by brontide View Post
Yes, this is gyro bias from thermal changes.

The gyro return a value of how much turn in each plane, but the value is actually an analog reading. When you arm the KK samples the values to create a "0" reading from which all others are compared to. Greater than "0" is rotation in one direction, less than "0" is rotation in the other. The problem is that during temperature change ( and this affects some boards more than others ) the "0" point changes causing the board to think that it is constantly rotating ( vertigo ) and the KK tries to compensate.

Landing and rearming will create a new "0" point and correct the problem.
Doesn't 1.5 use the sensor fusion/filtering proposed by scolton? high-pass filter gyros to eliminate slow angular drift terms, low-pass filter the accelerometers to remove the high-frequency noise bias.
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Old Nov 13, 2012, 03:14 PM
HeliHarry
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United States, OK, Tulsa
Joined Dec 2006
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Quote:
Originally Posted by viper522 View Post
I've been hunting KK2.0 buddycodes for weeks now, but nothing, are they not eligible anymore?
I just got my KK2. Where do I find the Buddy Code. If I find It I'll post it.
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Old Nov 13, 2012, 03:20 PM
Stop me before I build again!
United States, NY, Albany
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Quote:
Originally Posted by Dirt-Torpedo View Post
Doesn't 1.5 use the sensor fusion/filtering proposed by scolton? high-pass filter gyros to eliminate slow angular drift terms, low-pass filter the accelerometers to remove the high-frequency noise bias.
Yes, but it doesn't help because the underlying sensor is changing during flight. I am working on a way to feedback the error to correct for bias, but I have not gotten a chance to work on it lately. It's not as simple as it sounds.
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