Heli tail feels 'loose' but log yaw data is good

ArduCopter Traditional Helicopter
1

My TRex550 in a scale JetRanger fuselage feels a bit ‘loose’ in the tail. I’ve followed the Manual Tuning Instructions Yaw Axis section but am unable to understand the first paragraph about the required feedforward: I’ve checked a log file and see that the average RATE.Yout is 0.12 and the mean RATE.Y is -7.66. Dividing Yout by Y (as per the instructions) gives me a value of -0.01567, but where to I apply that value?

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If I look at the ATT.DesYaw and ATT.Yaw data the two graphs seem to be an excellent match, which I thought meant that the tail is responding well.

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Attached is the param file for the heli. Any suggestions about what I should be looking at and/or what corrections to make would be appreciated.

Jet Ranger after MagFit (COMPASS_OFS_Y still out of less than -400).param (21.3 KB)

2

Hi @abenn1 ,

any particular reason behind these settings:

ATC_RAT_YAW_FLTE,2
ATC_RAT_YAW_FLTT,23

If not, raise FLTE to 20.

Then share a flight log.

3

I can’t remember why those values, so I’ll do as you suggest. Thank you Ferrosan.

Next flight will be next weekend, weather permitting, so I’ll post a flight log then.

4

I’ve corrected ATC_RAT_YAW_FLTE and the tail feels much better. Thank you.

Here’s a link to one of today’s flights, as requested.

5

Hi @abenn1 ,

looking good. You could get better (and more “locked in”) feeling by tuning a little more the controller. You can increase ATC_ACCEL_Y_MAX to 60000 and use an aux channel for inflight tuning through a potentiometer (P and then D gains).

6

Thanks Ferrosan. The heli felt good yesterday but I’ll check out ATC_ACCEL_Y_MAX and see how much difference it makes. I’ll also read up on in-flight tuning, though I’m quite happy with the way it’s flying now.