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Old Jan 12, 2012, 04:47 PM
jesolins is offline
Find More Posts by jesolins
United States, TX, San Antonio
Joined Feb 2007
15,134 Posts
FF PID adjustments 101

First set the 500 mm as your defaults using the PID utility. Is your yaw holding with good resistance? If not then increase the yaw P. Increase your yaw stick if you want more yaw stick authority.

I suggest only changing one value at a time until you are sure you understand the effects of your changes.

Using the PID "Debug" utility
1. Make sure your adapter is in the normal not boot mode.
2. Connect the adapter to your PC and FF.
3. Power on the FF.
4. Open up the PID utility. Make sure it is the same version as your FF firmware.
5. Set the com port to the one your PC is using for the adapter and click open.
6. Click on one of the appropriate/close default frame sizes to your model at the top left portion of the PID window. You can make changes if needed as well. A suggested method is one axis at a time one value at a time to see the effects of your change. When satisfied then duplicate the values on the other axis. See below for PID tuning recommendations.
7. Click Send to write to the FF. It will respond with a small window with ?????! to let you know it has sent the data to the FF.

--The PID utility unfortunately does not read the current settings so do a screen capture or write down your changes and PID values.
--The save data seems to do the same as send.
--The Cal IMU will also work. Just wait as normal about 30 seconds for the green LED to go out on the FF.
--I do not know what the factory defaults button does.

PID tuning recommendations:

*Start with the defaults from the PID utility version that matches your FF firmware!

Rol*Pit_P: Increase one point at a time until you get the pitch and roll axis resistance and only one bounce to recover when the arm is test struck/upset. If you are seeing oscillations, then back off until they are gone.
Rol*Pit_I: Increase until amount and strength of self-leveling is achieved. You might have to lower P if you have this set too high. It is a balance decision between the two.
Rol*Pit_D: Adjust after the "P & I" to decrease repeat bounce or oscillations after a test strike/upset.
R_P_Stick_P: Increase value for more pitch and roll stick speed/sensitivity.
R_P_Stick_D: Like exponential. Decrease value for less pitch and roll stick sensitivity around the center.
Yaw_Stick: Increase 1-2 points at a time for more yaw stick speed/sensitivity
Yaw_P: Increase 1-2 points at a time for more yaw authority/hold.
Yaw_D: Increase or decrease 1-2 points at a time to eliminate heading lock searching.

After making PID changes, it is recommended for safety to first test your controls while the model is safely tied down. After that confidence check is satisfactory, then go fly low over soft grass to determine if the changes made a positive stability difference.

Hope that helps.
@ Snapper,
Thanks for the English v1.24 PID app.
Quadrocopter and Tricopter Mega Link Index
Originally Posted by alek3d View Post
I do not think so. I am flying HK boards in quad and tri and it flies great. The point with KK boards is to calibrate ESCs via the board - it is not enough to calibrate them separately, and then it is absolutely essential to make the stick calibration to set mid points. Then it flies great. Check out my tricopter, this was shot about a month ago or so.

I also flew MultiWii with my T9X and I also did not have any problems, you just need to know how to set everything up and also do some fine tuning.

Another update on FF setup. I changed PID settings and now I do not need expos on ail and ele, but rudder is still very weak, it works though. So I believe I also need to tune up PID settings.

Can someone explain what are those abbreviations R_P_Stick etc?
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Last edited by jesolins; Apr 17, 2012 at 10:21 AM.
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