Hello, I'm try to setup my Nex e6 550 FBL with apm 2.5. Already follow step by step on copter ardupilot (Traditional heli) wiki. It's almost complete, except my collective pitch. it's reverse. When i try to collective up, main blade is respond by push my heli down (swashplate up). I can control aileron, elevetor and rudder perfect. Then I try to test stabilize respond, it respond in wrong direction it should be.
Now, I push APM 2.5 in reverse direction (yaw180) but not change board orientation. it's work!!!. I can fly it in stabilize mode and alt mode. not yet in loiter, toilet bowl suddenly. HUD respond missing form it shoud be.
Some question!!! Does arducopter (tradional hel) support with jr nex e6 FBL? TREX450 swashplate drive main blade directly but nex e6 reverse drive.
Should i continue try to loiter or waypoint by current setup? i'm prepare to use external compass.
Can i compassmot Traditional Heli?
Thank you.
Replies
On APM2.5 and arducopter 3.2.1 Traditional Helicopter firmware.
From this period of last year, it's ending in crash my nex e6. I have funny and success with Arduplane.
Just few day ago I try to solve collective reverse problem and modify 1 line of source code. it's working well.
I can arm/disarm in normal stick position and tested in Stabilize mode and Altitude hold mode. it respond like it should be.
In Loiter not test yet due to lack GPS Module.
This's my modify on AP_MotorHeli.cpp (Brance: Copter 3.2.1 )
line 592 coll_out_scaled = _collective_out * _collective_scalar + _collective_min - 1000;
to
coll_out_scaled = 1000-_collective_out * _collective_scalar + 2000-_collective_max;
hope it help for some one.
Thanks.
This is my nex e6 pid at last before it's transform to rocket and hard landing. i'm not tuning I and D value and never tuning to reach Oscillation point in P value. i found that tail servo get more temperature than ever, tune Rate Yaw P and I lower. WPnav never test it.
My suggestion, Alway test with Training Gear it safe my main blade several time.
My pid value in the picture can fly in STABILIZE and ALT very well in my opinion (APM reverse front back).
I have the problem with respond of APM, If i set it following the wiki. Try to reverse ch3 on transmiter it must ARM APM at full collective.
When i reverse APM front back direction (not orient value) it CAN FLY in STABILIZE and ALT very well.
After I try to setup APM to TRUE direction from first step again. It can STABILIZE by same PID Value and transform to rocket in ALT MODE and crash by panic pilot error!!!! it wasted my budget. hope this help and sorry for my english language skill. GOOD LUCK!!!.
Hi Taweesak,
I am currently setting up an E6 with APM 2.5. Would you mind sharing your PID settings as it may save me some time?
Like you I was wondering if the APM needs to be mounted upside down in order to get the collective pitch going in the right direction when flying in alt hold mode.
I have external compass with mine since I needed one on another project that I was working on. I plan to mount it on the tail boom.
Richard
Taweesak,
Compassmot won't work with the tradheli so an external GPS+compass is a good idea.
I don't think turning the APM around is going to work. Instead it's best to reverse the direction of motion of the servos on the MP's tradheli setup page.
When doing the RC set-up on the MP's radio calibration page, the green bars on the screen should all move in the same direction as the physical sticks on the transmitter *except* for the collective pitch control (channel 3). So when you move the transmitter's physical collective pitch stick up, the green bar on the MP screen should move down. If it doesn't then you should reverse channel 3 in your transmitter.
Hi Randy/Taweesak,
I have just started to get an E6 converted to use the APM 2.5. One thing that I have been wondering about is how the APM would adjust the collective pitch based when in altitude hold mode. From what I can tell the APM moves the swash plate up for positive pitch. On the E6 the swash plate needs to move down for positive pitch.
In Acro mode, I have been able to setup all the servo directions correctly. So adding positive pitch moves the swash plate down. This means that I have reversed channel 3 in my transmitter as you have outlined. Where does the APM learn to move the swash plate down for positive pitch?
Thank you
Richard,
Just to be clear, when reversing ch3 in the transmitter, make sure the green bar in the MP's radio calibration page move in the opposite direction to the physical stick. If you've got that correct then your channel 3 is set-up like everyone else which is good.
So if the above is done and you're able to fly in ACRO or Stabilize then it should all be set-up correctly. You could confirm by switch the vehicle into AltHold mode and make sure the swash moves in the correct direction when you push the throttle stick up or down. You could also try just lifting the vehicle up and down quickly to ensure the swash moves up and down in the correct way.
Hi Randy,
Ok so channel 3 direction is now set to move in opposite direction to the stick. In MP's page for heli setup the Collective bar moves down for increase in pitch and up for decrease pitch. This will now allow the heli to fly in ACRO mode.
Now switch to AltHold mode. When I move the vehicle up the swash plate goes down which increases the collective pitch to the blades. This is opposite as to what should happen. I believe that the AltHold should have a reverse direction switch to change the swash plate collective movement direction. This when set would make the AltHold feature move the swash plate down (reduce collective) when the heli moves up. Does this make sense to you? Or am I missing how AltHold works?
I assume that it is not a good thing to change the H_COL_MIN to be higher than the H_COL_MID and H_COL_MAX to be less than the H_COL_MID. I tried to to see if it would change the direction of the AltHold Correction.
Thanks,
Richard
Richard,
So sounds like the transmitter's pitch stick is still set-up backwards. So I didn't say the MP's heli setup page but rather the MP's radio calibration page.
So I got it setup now.
What I had to do was switch the aileron servos, move my elevator servo so that I basically reversed the collective response for the ALThold. The pitch stick and cyclic reversers are then set to get those going in the right direction. Then the APM had to be rotated 180 degrees in order to get the gyros for the cyclic to work in the correct direction. Now all is good.
In ALThold:
- Swash plate now moves up when the heli moves up. This means that collective goes negative to counteract the upward motion of heli.
- Opposite is true for downward moving heli.
In the APM parameter list it sure would be nice if there was a byte or two that had bits that could be used to set the gyro etc correction direction for odd ball cyclic configurations like the E6.
Setup of the tail is next then it will soon be safety flight test :-) Hopefully it won't be a "rocket" as Taweesak experienced. I will take your advice and put some training sticks on the heli for safety.
Richard
Richard,
Ah, sounds like good progress. Rotating the board 180deg will cause trouble if you try to use Loiter eventually though. Instead of that I think you should be able to change the angle of the servos in the tradheli setup screen. I think changing each servo's angle by +180 or -180 will do it. So for example, if one servo's angle is now "60" make it "-120". if it's "180" make it "0". If it's "-60" make it "+120". In this way you should be able to reverse the servo's response to roll and pitch but it won't change how the servo responds to up-down changes.