AC3.3 TradHeli Release Discussion

WARNING to TradHeli users:

Do not attempt to fly AC3.3 until you hear otherwise from me.  I have not even bench tested it yet, let alone test flown it.  There are quite a lot of changes that have gone in that could be crash-o-matic for helicopters.

AC3.3 release for Tradheli is likely to be delayed.

This post will serve as the official release progress thread for TradHeli.

Warning: DO NOT FLY RC6!  It has a critical bug that will likely end in a crash.

Warning for RC5:

RATE_YAW_FILT_HZ param will change defaults from 5Hz to 20Hz to be more suitable for helicopters.  If you have never changed this parameter from 5 before, then it will automatically update the value to 20 without warning.  This much faster filter will probably require reduction in your P and D terms, and the yaw may oscillate badly.  Be prepared to retune these.  As a safety measure, probably cut them in half for your first take-off.

Warning #2 for RC5:

I accidentally broke the Landing Detector.  It will probably never trigger.  You should land in Stabilize mode, or be prepared to shut down the motor as soon as it touches the ground in Alt_Hold, Loiter, Auto, etc.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • My 450 crashed yesterday. It was very weird. I had a successful first flight and then on the second flight on its way to waypoint 3 it started to pitch for and aft violently and then I believe a linkage broke and it went down. During the preflight if the heli sat in one spot for more than 5 min I would get a "Bad Accel" warning. I would then need to shut it down wait about 5 min and restart. It would than go away. 

    I have posted the log file on the 3.3 Traditional heli blog. Any help you could provide on this would be greatly appreciated. Also, when I look at the log it never states that it was in Auto, but it was following Waypoints and my switch was in Auto. 

    Very weird if you ask me. 

    2016-04-03 11-20-16.log.xml

    2016-04-03 11-18-55.tlog

    • UAS,  I just looked at your logs and you're IMU vibrations go crazy for 15 seconds or so.  I wonder if the Flight Controller came lose off the frame.  Just my thoughts.  I'm still using 3.2.1


      David R. Boulanger

  • I see the test version of the firmware on the MP has been updated to Heli AC3.3.3-rc2, compared AC3.3.3-rc1 has been updated, what does? Fixed 3.3.3-rc1 tail swing slow "golden fish" problem?

    • I just tested the new version last week and I was able to tune the tail wag out. Super stable. I did have it complete a full mission and when it yawed to land at RTL it suddenly got into a pitch oscillation. I will lower the P on pitch a little for the next flight and it should fix that. I might have it a tad to high.

      Great work Rob... Thanks for all the support.


      • Are you saying that the latest beta firmware AC3.3.3rc2 solve the problem of the tail swing?

        • No not exactly. I had to increase the P on the Yaw. It was to low so the tail was not keeping up with the wind and torq. Now the tail is rock solid in wind. 

          • I have experienced a lot of debugging, to stabilize the state


          • Thank you for the reminder!

            I replaced the ALIGN Trex 500 DFC swashplate servos to replace the somewhat curved tail pipe, and then, carefully re-adjustment of the pitch, at AC3.3.3 FW, again raised a number of Yaw rate P value and D value now, basically we have been quite satisfactory rear locking effect appears to be AC3.3.3 firmware and change the magnitude of the contribution Rate P values.

          • Nothing actually changed in the control loops for this release.  I think the improvement you are seeing might be due to improvements (noise tolerance and filtering) on the EKF which leads to a better, more stable, rate feedback into the rate control loop.

      • Can you give a description of what happens in a pitch oscillation. Thank you
This reply was deleted.


sam liked Jimmy Oliver's profile
Aug 25
Mike Whitney liked Mike Whitney's profile
Jul 19
Abdulatif Tlaib liked Ryan's profile
Jun 24