Trex 600 stretched (700) Pixhawk 3DR tuning

update;

I re-calibrated the compass outside and get much better reading!!

here is pic of the calibration results (offsets)

I see no bird eating here heheheh :slight_smile:

hope this time is getting me better !!

Thank you
Ozzy

Ozzy,
I’m surprised that your mag cal had that effect on your loiter performance. I think you can start doing some high speed flying in stabilize, ALTHOLD and LOITER. Just build up in speed and if you see anything suspicious slow down and pull the logs so we can look at it. If your flight at high speed is good then you can move to AUTO missions.

I appreciate your help Bill!

I have a video recorded the loiter flight

Please look at it and see what do you think ?

Thanks again
Ozzy

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Looks good to me. I think you are ready to move on to forward flight.

Boy you fly in a very confined space. You are very trusting of these systems. If you had any type of failure that caused you to lose control of the aircraft, you’d have no where to go. You really need to consider what could happen and take precautions to protect yourself. I’ve done some testing of some experimental rotor configurations and I’ve placed trees between me and the helicopter. Even with my reliable helicopters, I still have a bigger area where I can get away from the aircraft if there is some type of failure. Please be more careful.

Agreed, very very dangerous. Especially with all those walls around you in loiter mode. The GPS signal can be getting multipathing causing jumps in measured position.

Somebody in my hometown was killed by a model helicopter slightly smaller than this. You cannot ever feel this comfortable around a helicopter while in flight. Everyone needs a healthy fear of them.

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Your guys right! I never did that till the recent build,
I am a member of a realy nice flying club and we have big runway.

Its becaue tnere is a lot of tests and so many changes, was unable to go to the flying site 5 times aday between my work.

I had somw work during the day and I had to stay wake overnight to test flight the system!

But yes, I am going back to the club this week:)

Just wanted to ask queastion;
Do your guys like the old pixhawk 1 (3dr pix4) better than the new 2.1 one and why?

I am lookinng to buy another one for my other orange costum made heli, but I run through a good deal; sombody want to sale me 2 new pixhawk 1 (3dr pix4) for $100

So I was wendering if there is a reson behind choosing the old one over the new one …

Thank you so much!

That looks really dangerous.

It is very dangerous,
But I always fly and there is something between me and the heli, like Columns, big tree or I stand behind the door…

Incase if something happen will hit the walls and fail down…

I had one accident 15 years a go at the flying site, was flying hard 3D cross the runway and on blades came of about 50 feet hit the car window !!

So sometime it’s even more dangerous in the flying club than behind wall since there are more people around! Specially if the flying club is closed not open !
But anyway thank you for the comment
Ozzy

Edit: post deleted due to Some changes in FC mounting.
Auto flight was tested, and the helicopter heading between waypoints not quite good!

Heli was very fast and turn on its side instead of straight, same old problem before tuning!

Thank you to all people here who tried to help
And I appreciate all inputs and comments
Ozzy

Ozzy,
I saw that you had a version that had L1 Nav. Did you use L1 Nav or regular copter navigation for your auto mission?

I’m not sure what you mean by this. do you have a log I can look at?

I think I am suing the regular copter navigation
because my L1 is set to 0

when the heli reach the way point 1 and turn to waypoint 2 it will go back flying reverse on the tail just like when you back up the car then turn left or right to complete to the next waypoint

so I must turn the L1 to 1 to activate the speed control?
I copied your parameters from other post and listing them down here, any changes to the current parameters ?

thank you very much

from Bill’s other post copied: -
WPNAV_USE_L1_NAV - enables/disables L1 navigation
WPNAV_L1_LTR_RAD - radius used in loiter mode. aircraft always flys clockwise around loiter point
WPNAV_ACCEL - set max acceleration in x axis. Initially use 100. it will provide smooth accel/decel.
WPNAV_SPEED - sets default speed for wp navigation
WPNAV_ACCEL_Z - set max vertical acceleration
WPNAV_SPEED_UP - max climb speed
WPNAV_SPEED_DN - max descent speed

L1 parameters
NAVL1_DAMPING - same as Plane L1 parameter
NAVL1_PERIOD - same as Plane L1 parameter
NAVL1_XTRACK_I - same as Plane L1 parameter
NAVL1_TURN_SF - scale factor for coordinating turns. The L1 nav includes an input to the pedal to coordinate the turn. If you think it is not enough or too little, this scale factor allows you to adjust it. Start with the default value of 1.0 and recommend only changing by 0.05 increments if you think you need more or less.

Speed control parameters which are standard PID parameters. Use the default values initially. The FF value is important for reducing transients when starting L1 nav with some speed on the heli.
SPDHGT_VEL_P
SPDHGT_VEL_I
SPDHGT_VEL_D
SPDHGT_VEL_IMAX
SPDHGT_VEL_FILT
SPDHGT_VEL_FF

Ozzy,
Don’t use L1 Nav. Only more experienced users should use L1. I was only asking because I wanted to be sure you were not using it.
Please post a log using the copter nav. I suspect that your waypoint radius is too small.

Oh great! You saved my heli :slight_smile:
I changed the L1 to 1 just two hours a go and went to the flying site to fly it but I forget my telemetry connector cable !!

So I returned back home and checked my email and found your post …
I changed back to 0

I will go back tomorrow morning to fly and upload the logs

I appreciate your time and help

Ozzy

when you fly tomorrow change your WP_RADIUS to 500 and see if you still experience the same problem.

That’s the default waypoint behaviour. Use spline waypoints instead, if you want smoother turns.

Use WPNAV_SPEED for controlling the speed (in m/s). Start at something slow (3-5m/s) and work your way up.

Hi everyone,
It’s been long time since my last flight with this setup
I did some change to the rotor head, I installed 3 blades rotor hub (AS350)
I never run the heli since 2019
I need to upgrade my pix hawk 2.1 firmware… also I need to set failsafe so that if I lost the radio connection, the helicopter will return back to the same starting spot and land safely…

Please;
1- do I need to redo all the PID all over again!?
Is there Auto tune I can use to make it easy?

2- how to program the failsafe?
I am still using my old 14SG futaba and Frsky TFR8SB RX
Note; I re-installed the pixhawk using floor carpet under !
Yes :rofl: I use it to lower vibration…
I appreciate any help

@flyingdragon Glad to see you are getting back to flying your helicopter.

I would say that it would be worth re-doing the tuning. There is now an Autotune feature for helicopters. It will take some time to read through the instructions and can take 6 or more flights to complete the tune. However, it will tune the gains for you. Here is the link to the wiki for the heli autotunehttps://ardupilot.org/copter/docs/traditional-helicopter-tuning.html
Follow the instructions for “preparing for tuning” then go to the section for autotune.

Follow the wiki instructions for the failsafe
https://ardupilot.org/copter/docs/radio-failsafe.html
but I wouldn’t allow it to use any auto modes until you have completed the tuning and checked that it flies well in loiter mode. Please only use stabilize or althold until you have tuned the heli.

I would be careful about the type of materials that you use as vibration dampers. This doesn’t sound like a good idea

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Than you Bill, yeah I am back to the hobby… wiped
the dust off my Helicopters and changing the rotor head to 3 blades ( ASYMMETRICAL shape) no old school align bead, I installed very nice scale looking as350 head

Now after installing the new swash and the rotor, I noticed the IM_STAB_col 1, 2,3 and 4 are reversed!

So 1 change the positive pitch value and 4 change is the minimum pitch stick!

In my radio the pitch is reversed but this don’t matter as I tried to make it normal in my radio but still same problem

Dose it really matter.
I can move up and down the stick and the pitch is great!
I set it 0 stick down med stick 0 and goes to high

Pitch degree low stick at 0 mid stick 0 then goes to +12
Thank you so much

This is difficult to diagnose like this. If the swashplate motion is reversed when moving your collective stick then you have a set up problem. I would suggest that you set your IM_STAB Params back to the default values. Then follow the swashplate set up exactly how it is laid out in the wiki. There is even a video. This should help you correct this problem.
https://ardupilot.org/copter/docs/traditional-helicopter-swashplate-setup.html

perfect, I am glad everything in the link and easy to follow…

do I need to update the unit firmware to be able to use the autotuning future?

my second Q, since I’M using 3 Asymmetrical blades ( flat from bottom) what is the recommended MID stick to be at?

the Wiki mention mid at - 2 and min at -5 with max at +12
another issue;
I have about 1mm play in my rotor grips caused by the Turnbuckle Rod Ends, they are not tight enough, the metal balls not tight inside the metal turnbuckle ends, this result 1mm free movement in all 3 blades… I am guessing that the airforce will lift all 3 blades with the same amount so that will not bring vibration issue!

thank you!
AS350 head rotor