9CHP Doesn't Mix Collective Evenly (Pos/Neg)

[jlr]

I spent about 3 hours trying to set up CCPM my new TREX and I could not get the pitch at full positive to come out anywhere near what I got at full negative. I have followed the procedure from the manual and Finless Bob's videos very carefully (great videos by the way).

Settings:
a. The pitch curve is the standard 0, 25, 50, 75, 100.
b. The end points are all at 100/100
c. The DR/Exp are all at 100%/0
d. All servo arms were positioned to require the smallest subtrim values to center. (The largest subtrim setting actually used is like -11).
e. All the mixing levers were set at horizontal.

Everything looked perfect at 0deg but no matter what I did I would get like +11/-14 with the swash pit setting at 50. :arggg: I finally measured the swash movement and sure enough the swash was moving significantly further down than up. It was moving about 5/16 up but like 3/8 or 7/16 down. Digging a little deeper I noticed that even if I went to the "Servo" display on the tx, you could see the bars for the 3 ccpm channels move further with the left stick all the way down than they did with the stick all the way up, yet they were all at 0 with the stick in the middle. I thought I might have some weird setting in the radio some where so I even tried a fresh model, set it to SR-3 and went to the servo display. SAME THING. If you actually count the pixels on the display, the bars are like 10 pixels tall for full negative, but only 7 pixels tall at full positive? :dontknow

Does anyone have any suggestions? Can anyone with a 9CHP verify or deny that their radio behaves this way?

TIA,

--Jeff

[DebianDog]

There is another menu where you can adjust it. Not in front of my radio right now.

[BarracudaHockey]

HOV-THR set to INH
HOV-PIT set to INH

High/Low pitch set to man and set the VR to null.

You have either a knob or VR not centered and one of the above mixes playing games with you.

[jlr]

HOV-THR set to INH
HOV-PIT set to INH

High/Low pitch set to man and set the VR to null.

You have either a knob or VR not centered and one of the above mixes playing games with you.

I don't think that is it. When I was setting up the TREX, I was in IDLE-UP 1 and the manual says that these functions are only in the NORMAL condition. I would have to double check, but I think the default is INH when I checked the "clean" model.

Thanks for the suggestions, I look tonight and let you know for sure.

--Jeff

[DebianDog]

The ratcheted switches on the side?

[jlr]

HOV-THR set to INH
HOV-PIT set to INH

High/Low pitch set to man and set the VR to null.

You have either a knob or VR not centered and one of the above mixes playing games with you.

I don't think that is it. When I was setting up the TREX, I was in IDLE-UP 1 and the manual says that these functions are only in the NORMAL condition. I would have to double check, but I think the default is INH when I checked the "clean" model.

Thanks for the suggestions, I look tonight and let you know for sure.

--Jeff

Okay, Barracuda and DebianDog were absolutely correct. I missed the reference to HI/LO-PIT in my first response. HI/LO-PIT applies to all conditions and the default is that LO-PIT is disabled (MAN), but HI-PIT is enabled and controlled by VR(e), the right-side ratcheted switch. I switched HI-PIT to MAN and now everything looks as I expected it. Thanks for the help guys!

My faith in Futaba is restored, at least as far as building stuff. Their manuals still leave a little to be desired.

[DebianDog]

Okay, Barracuda and DebianDog were absolutely correct.


:woot

Their manuals still leave a little to be desired.

WORD!

[BarracudaHockey]

:glasses2:

Dont ask me how I knew.

[franky92]

how did you knew? :tongue :happyd

[mcomet]

Hi!

So I just ran into this exact problem and fortunately found this thread, fixed it right up. Thanks!

My question is...what on earth are all these settings, how would one use them and why? Being a newbie, I mean what is HOV-THR HOV-PIT and High/Low and the VR stuff?

Thanks!
comet

[DebianDog]

Micro adjustments basically. I have never known any 3-Ders to use them... although Stator Gator does use the dials to adjust his idle on his gasser.

[jlr]

My question is...what on earth are all these settings, how would one use them and why? Being a newbie, I mean what is HOV-THR HOV-PIT and High/Low and the VR stuff?

Let's start with the VR question. Futaba uses VR to designate the knobs and sliders that you can assign to functions, similar to the way you assign switches except that the VR controls are proportional and switches are 2 or 3 discrete positions. If you look at the first couple of pages in the manual you can see the labels VR-A through VR-E. (Going from memory so the details may be off, but hopefully the concept is making it)

From what I've read and played with the HOV-THR and HOV-PIT allow you to assign VR inputs to "tweak" the throttle and pitch curves "around center" for the normal condition only (hence DebianDog's comment about 3D pilots not using them; they don't spend much time in normal mode).

HI/LO-PIT allows you to assign VR inputs to control the max positive (HI) and max negative (LO) collective pitch. I was surprised that the default is that HI-PIT is active and assigned VRe (Right-hand slider or ratchet). LO-PIT is disabled by default.

--Jeff

[mcomet]

Yeah after I posted I actually cracked open the manual and read this and realized what VR was etc... heh.. :)

I still don't get "around center". So basically it adjusts the curves while flying around center stick... I can see why people don't use it...

And yeah now I see why HiPIT was then throwing off my swash pitch so that I wasn't getting enough positive pitch...

cool thanks!

comet

[BarracudaHockey]

HOV PIT and HOV THR are fine adjustments to tweak your head speed in a hover in normal mode, besides not flying around in normal much, so many people go straight to 3/4 stick hover or set their normal curve up for it when they do start using idle up its useless because it only changes the center pitch and throttle point. An example would be flying on a very hot or cold day when your performence around hover changes but you dont want mess with your needle or normal curves.

High/Low PIT is for the contest guys that need very fine control over how thier heli behaves in flight w/o tinkering with pitch curves, say the weather changes and it gets windy and they need more pitch or whatever.

For most of us they are just a PITA during setup and another thing that can get changed by simply picking up the transmitter, hello we have digital trims to prevent that these days.

[sbmon]

I had the exact same problem with my 9chp super radio. I find it odd that futaba did not set these functions as inh by default. I am however having trouble figuring out how to turn the VR to null as Andy (BarracudaHockey) said. So how do you set the VR to null?
Thank you
shawn

[DavidH]

http://manuals.hobbico.com/fut/9c-super-series-manual.pdf

Page 93 of the manual will tell you have to Null the Hover Throttle and Hover Pitch
functions.
That is a link to the manual above.

Simple to do. Go the Hover Throttle and Hover Pitch menus. Make sure the knobs are centered before inhibiting the functions.
Highlight the Mix part of the screen, change it from ON to INH or Off.

David

David

[sbmon]

David
Thank you for the fast reply. I was able to turn the hover throttle and hover pitch functions to inh, and the hi/lo function I also set to manual but I do not know how to turn the VR to null(vr are the sliders on the side of the radio correct)l? Am I missing something?

[DavidH]

but I do not know how to turn the VR to null(vr are the sliders on the side of the radio correct)l? Am I missing something?
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What functions are the sliders controlling? All you have to do is go into the menu of the function that the sliders are controlling and Null or Inh that function.

http://www.futaba-rc.com/faq/faq-9c-q542.html

According to Page 94 of the manual. They have the left and right sliders are assigned to the Hi/Lo Pitch function. Page 94 of the manual will explain how to disable them. When all else fails Read the Manual.



David

[jlr]

For what its worth, I just set the HI/LO functions to INH. I left the VR assignments as they were and that worked fine. I think in the HI/LO menu you should be able to move the cursor to the switch assignment field (don't know the actual name on the screen) and use the dial to select Null.

--Jeff

[Pla]

Just make sure when you set HI/LO to INH, you do it for all modes (Norm,Idle1,2,3,Hold) and not just in Norm. Also make sure it is at 100%

I am glad I saw this thread - mine were also active (Hi in all modes).
I didn't notice any problems because my slider was at top (100%) by chance.

The Hover throttle/pitch can be enabled for Idle 1 also - it has 2 options Norm or Norm/Idle1

I guess they may be useful to field adjust all curves end points and middle points at once. Depending on air density.

Since I still learn to hover nose-in, I disabled HI/LO...

[nmrider]

What swash selection are you all using for CCPM on the 9CHP?

Thanks.

[mcomet]

For my TRex 450 it is SR-3.