Adjusting pitch

[dave26985]

O.K. guy's, what am I doing wrong ?
I am trying to set my pitch angles. Everything has been done per finless' vid's. It all looked good untill I went to check & adjust my pitch. I can get an easy 14 deg. pos.( I will set that to 11 deg.), but I cant seem to get more than 5-6 deg neg. And in normal mode the only way I can get 4 deg neg on low stick pos. is to adjust point 1 on my pitch curve all the way down to 25% !! I have plenty of room on the shaft to go down further, but I can't figure out what needs to be adjusted. Any Idea's ?
I am using a DX-7
Travel for all 3 servos is set at 100%
Swash mix Aile - 50%
Elev + 50%
Pit +65%
Pitch cv Nor 40-45-50-75-100

Pitch cv st-1 0-25-50-75-100
Thank's for your help. Dave

[mjdee14]

Have you set up your linkages per the Gaui Instructions? The front belcranks should be level and the pitch lever should be straightup and down...

Maybe if you could post some pictures we might be able to see something that is not as it should be.

Since the Gaui head linkages are non adjustable everything "should" work out OK..

having 14 deg pos seems like an awful lot.....if some of that was toward the negative you would be OK.

i am also using the DX7 and didn't have any problems, I set the heli per instructions and just used the basic DX7 settings.

You might try another model on the DX7 jsut to make sure you don;t have something turned on or off that shouldn't be....

Like I said...Pictures might help.

[xfaega]

Make sure that at center stick your pitch is 0. If not then you will need to redo the length on the push rods. You should get -11, 11 with the default setting of 0,25,50,75,100.

[mjdee14]

I forgot the one linkage that goes up to the head...mine is 82mm center to center of the screws....

Attached are a couple of pictures of my head set at zero...so you can see the linkages...

maybe you will see something different.

[dave26985]

Yea I know, if I could get some of that extreme positive pitch to go on the negitive side I would be all set.
Yes my bellcranks are level at half stick, as I set everthing up using the manual & finless' video's.
It does not make sense to me, but it seems like the whole swash needs to come down a bit to equalize the neg. to pos. pitch. How can I bring it down while still keeping the bellcranks level ?

[dave26985]

Yea, I will go measure that link that goes from the head to the swash and see what I have their.

[mjdee14]

You don't have a couple of the plastic rods swapped do you?

Starting from the bottom...my rod lenghts are 52mm bellcrank to swashplate....42mm mixing arms to flybar cage......37mm seesaw to bell-hiller arm...and as said before 82mm swash to bell-hiller arm....

my radio swash is currently set at 3 servos 120 deg, aile +60 elev +60 and pit +60


*** notice my first picture...are your mixing arms also level with the bellcranks level ?

[dave26985]

Thanks mjdee14, I will check all those meas. tomorrow. Have to get up at 6 am for work so I better get a couple hours of sleep tonight. Thanks again. Talk to you later.

[dave26985]

Yea the mixing arms are level with the bellcranks at mid-stick

[Pinecone]

I think that part of the problem is, a very small change from visual level on the bell cranks is a good bit of change on the head. I have the ReadyHeli Zero Alignment tool, and I had to do through the setup several times to get things right.

You could also do the iteration method of increasing swash travel until bind, then lower or raise to elminate, then repeat until it binds inboth directions at the same swash travel. But instead of adjusting the lower links, you would adjust subtrim. Or you could adjust the servo to bellcrank links.

On mine, I swaer I had it right, then it moved, then I did it again, and it "moved" again, and after several iterations, it finally was right.

And level the swash in mid travel BEFORE you adjust for 0 pitch.

[Mikej]

Dave,

If the Elevator lever is parallel to the main shaft (two red lines on piccie) then this MUST be half stick, the pitch / alieron levers should line up with lines on the frame also (yellow lines). If you set the half stick from the elevator arm and then level the swash, then connect the 45mm links, this is the correct position for the pitch and aileron arms, now connect your servo links (equal lengths) and adjust the servo arm so that it is parralel to the aileron and pitch arms (by repositioning arm / sub-trim)

Cheers,
Mike.

P.s. the elevator screws do all line up straight - they just look out due to the angle from which I took the photo

[mjdee14]

with everything at zero my the distance from the bottom of the swashplate to the heli frame is 15mm...

Post pics if you can....

[dave26985]

My camera takes crappy close-ups. But im starting over again, go threw bottom to top and find out were I screwed up. Thanks for all the help, Ideas, & measurments.
I will let you know were I messed up when I find out.

[dave26985]

I got it right ! I think what happened was that the first time I started my set up, somehow, I did not use a normal pitch curve that gave me 50% at mid stick. It was more like 45% instead, That made enough of an error to throe me way off.
Thanks for all your help and ideas. Should be ready for maiden hover in the next couple day's.

[mjdee14]

Dave...

Glad to hear you got it straightened out.....