Need help with my mini VBar

All,

I am trying to install a Mini-Vbar on my Dragonus II helicopter. This
is my first experience with a virtural flybar. It appears that my Mini-
Vbar module is defective. However, before sending it back to Mikado,
I want to be sure that it isn't just me doing something stupid.
Attached are my setup file and two photos of my helicopter.

I'm using a Futaba T8UHP transmitter (with the TM-7 FASST RF module)
and a Futaba R607FS receiver. The swash plate servos are Futaba S3154
and the tail servo is a Futaba S3156. The rotor head is a Mikado
MIK4310. The helicopter worked fine with its flybar, prior to this
Mini-Vbar upgrade attempt.

Here is a summary of my installation effort so far. (The ESC is
disconnected and an external battery is connected to the receiver
during the setup steps described below.)


* Step 1 - Load Preset

There is no preset for the Dragonus II, so I started with "Universal
Setup 120 Degrees Reversed".


* Step 2 - Calibration of Your Radio

No trouble here, except that I was unable to get any of the channels
to produce 100% range on the display. (I get about 93%.) However, I
am puzzled by the fact that the expert menu shows the collective as
coming from channel 3 of my receiver, when it actually comes from
channel 6. (Changing that 3 to a 6 caused the collector channel to no
longer function. So, I left it at 3.)


* Step 3 - Tail Rotor Settings

No problem with this.


* Step 4 - Setting Up the Swashplate

Here I am having a lot of trouble.

I cannot get the swash plate to move properly with any combination of
servo connections and direction reversals. The best I can do is a
case where the cyclic is correct, but the collective is in the wrong
direction. (This was achieved by connecting the rear, right and left
servos to channels 1, 2, and 3 respectively with no servo directions
reversed.) If that were the only problem, I could compensate by
turning over the blade grips so that a downward swashplate movement
causes an increase in collective pitch.

However, even with that setup, the servos do not move consistently.
The three servos do not move by the same amount when I change
collective. If I start with the throttle stick at mid position and
move the swash plate up or down, all three servos move in the same
direction, but not by equal amounts, causing the swash plate to tilt.
Sometimes a servo will start to move in the wrong direction before
changing to the right direction. When I apply right cyclic, the rear
servo moves slightly up. It moves slightly down with left cyclic.
Servo movement is erratic and not reproducible.


* Step 5 - Level Swash

The buttons in this panel do not have the expected effect. If I try
to move the swash plate up, two servos move up, while the other moves
down. I can fix that by changing the directions in the Step 4
panel, but that screws up the movement using the transmitter sticks!


Any suggestions?

Duane



Edited 1 time(s). Last edit at 02/25/2010 11:08PM by RV.

Hi.

Step two: you "must" increase servo throws in your tx to achieve 100 %.
Collective ... sure there is no mixer active in your tx? Really a clean, fresh H-1 model memory?

Step four: you "must" connect the servos the way the graphics show in VBar ... never-ever switch
servo wires to correct sth. Then, you use Servo reverse untils cyclics run correctly, then you may
either do a grip-flip OR check Collective Reverse in the Expert Menu (doctor's hat).

Those servo movements, are they in Setup Mode (would be a bad thing, but can be explained
by changing servo wires at VBar randomly ... the swash plate mixer won't notice that) or in
Flight Mode (what you see is what you never get, the control loop is active in Flight mode and
without the heli being able to react to the inputs, the servo movements look funny.

Those Servos, are they in perfect working order?

Step five: has to do with random servo connection I guess, too

For the Dragonus, I'd recommend starting with the T-Rex 450 Preset.

According to your setup-file, you could maybe use a slightly shorter tail servo horn.

Best regards

Eddi

Born to fly ...
forced to work.

Thanks Eddi.

As I suspected the problem was due to user stupidity. Following your suggestion, I checked my transmitter and found it set for ccpm. I know I changed that, but I must have forgotten to hit the "set" buttons after making that change. Fixing that setting made a huge difference and all the problems I was having went away.

I still haven't tried to fly it. But, at least the setup is working like it's supposed to.

Duane