PID Settings for Tradi-Heli

Hello Everyone,

I have been searching for info on how to to set the PID for Traditional Heli. Most of the information i find is based for the quads, as i have been testing and playing around alot with the PID in my Trexx 600 Heli. I have the Heli set to where it actually hover on its own on stable mode, but when i switch it to Alt_Hld, Loiter, position hold  or others it wont stay as the command is spcified to do. 

on Alt hold, it will either shoot higher to where i almost loose sight of the the heli.

on position hold. it will wonder off way far from its position.

on loiter it does the same as Alt-hold but it will descend to land as well sometimes.

on circle it does what it is commanded to do but it circles once or twice and then it will start descending as its getting ready to land.

on RTL. it does well. no complaint on this one.

One more thing, why is it that on Mission planner in the flight data screen the the first 2 modes work find and on the third it doesn't correspond to the the switch settings. I've tried ticking on the simple box next to the modes setting and it doesn't do much.

for example

if I set the switch to stable on switch 1 it will correspond correctly

if i set the switch to loiter on switch 2 it will correspond,..

if i set the switch to RTL, Circle, Position Loiter or others,on switch 3, it will not correspond... it will show stable or sometimes...sometimes it will show unknown...

i can provide videos on all command modes as a demonstration to my questions and problems.

BUt basically i am looking for some kind of basic literature on Setting PID, I have tried to understand the ones for the Quad and kind of integrated that with the Traditional Heli but its not as good as for the quads though.. Any info might help at this point.. I think we need to get together on this and make a small basic manual. I have seen many people asking similar question  and problems.

Hope i am not asking for  too much....

Thx and Happy New Years.


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  • Developer


         One thing you should do is "arm the motors" just like on a quad by holding throttle down and rudder fully right for about 5~6 seconds.  This re-initialises the barometer and in the case of a quad would also allow the motors to spin..this second function isn't relevant for a heli but that's the price of piggy-backing off the quad code.

         It would be great if you could post some logs of the altitude hold problem.  Also are you using a sonar or barometer?  presumably it's going high enough that it's the barometer that should be being used but still, some logs would be very helpful.  It sounds very much like your alt hold isn't doing anything.  I've had a number of hardware issues (barometer broke on my oilpan and it's too cold in japan for the sonar to work) so I have been unable to test alt-hold in >1month.

         Are you saying that RTL's altitude hold works?! that's very surprising if it's not working for loiter.

         Re the mission planner issues, you've got the latest version of course?  i.e. you've pushed the help screen and then the download button?

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