mnwizard
04-07-2008, 11:00 PM
Thanks to Dierwolf, this is actually an older post of his -
Step 1. Remove Servo Arm links from swash (if you put them on the CNC Swash already)
Step 2. Turn ON your TX and make sure Throttle is to Zero as well as its Trim turned all
the way down.
Step 3. Set all the trims for Rudder/Aileron and Elevator to their midpoints
Step 4. Plug in your Helicopter and let the 4 in 1 initialize and servo's go to their neutral
position.
Step 5. After 4 in 1 shows green unplug the Helicopter and turn off the TX (if you have
servos that move very easily without power to them skip this step and keep TX away
from kids that might throttle up on it while your working)
Ok now all your servo's should be at their centers...
Check your Servo arms and make sure they are at 90 degrees to the Servo itself..
if they are not loosen the servo horn screw and adjust it as close to 90 degrees as
you can and screw back on tight.
Picture will follow next with more instructions below.
http://i32.tinypic.com/2enp4xc.jpg
At the center of this picture shows the 90 degree angle your swash plate should be
set at once it is set properly... Swash should be as close as possible to 90 degrees
from the main shaft looking both from the rear/front of the helicopter as well as from
the side... Once it is set this way it will hover with no drifting...
To get it at 90 degrees its very simple.... Looking from the back of the heli. Left servo
is your Elevator Servo...
A. Turn out (unscrew) to lengthen the rod making the swash plate tilt forward
or
B. Turn In (tighten) to shorten the rod making the swash plate tilt Backwards
Same goes for your Right servo (looking from the back) Which is your Aileron...
C. Turn out (unscrew) to length the rod making the swash plate tilt forward
(YES I SAID FORWARD)
or
D. Turn in (tighten) to shorten the rod making the swash tilt backwards
(YES I SAID BACKWARDS)
This is not your typical 3 servo swash where things are nice and neat
so yes each servo actually tilts the swash up and back from its position
in one corner at the ball.... which is why i said tilts foward/backwards so
you can grasp the movement better.
That being said, if the swash tilting backwards after the cnc upgrade
which it will because the CNC swash balls sit higher than the stock you
will need to adjust both links gradually at the same time, at equal turns.
I have found that 6 turns out on both servo arms brings it level, maybe
different on yours.. you dont have to keep clicking the ball ends onto the
swash balls each time, simply position them both against the balls with some
pressure and you will get a good view if you have to move them in or out more..
Do this until it looks pretty straight at 90 degrees..
Then click on the arms to the swash... turn on TX and do a test flight....
CNC Swash is much more sensative than the plastic low tollerance "Thing"
that was in there so dont go panicing if it vears a bit... in other words dont
take it slow and go up slowly get up there to 3 ft quick and see what it does
with no stick (Cyclic) movements....
If you eye balled it correctly it should hover just fine with very little
forward/backward or side to side movements... any movements that may
happen you cant just jump to the conclusion that the swash isnt set right.
1. is there a fan on in the room?
2. is there an a/c vent blowing in the room?
3. are you hovering over obsticles or too low??
if no to all 3 questions up there, then OK you can say its not set perfect yet...
try getting rid of the movement by using the servo trims.. once you get it
trimmed out.. leave trims as is and bring it down.
Now look at your trims....
Hmmmm aileron trim is to the right, meaning its compensating
for Left aileron...
This means swash is leaning too much to the left looking from back...
meaning the right servo (looking from back) needs its servo arm
shorted a tad bit (depending on how much you had to compensate
with the trim.. i find 1 turn for every 2 lines on the transmitter trim is correct)
Same for if trim was to the left just visa versa (lengthen right servo arm)
Same for Elevator, if trim is up means you need to lengthen servo arm on
left servo and if trim was down shorten the left servo arm.
once you made those adjustments the amount you think it should be set
the TX trims back to zero again and test...
And this is how it goes..
Step 1. Remove Servo Arm links from swash (if you put them on the CNC Swash already)
Step 2. Turn ON your TX and make sure Throttle is to Zero as well as its Trim turned all
the way down.
Step 3. Set all the trims for Rudder/Aileron and Elevator to their midpoints
Step 4. Plug in your Helicopter and let the 4 in 1 initialize and servo's go to their neutral
position.
Step 5. After 4 in 1 shows green unplug the Helicopter and turn off the TX (if you have
servos that move very easily without power to them skip this step and keep TX away
from kids that might throttle up on it while your working)
Ok now all your servo's should be at their centers...
Check your Servo arms and make sure they are at 90 degrees to the Servo itself..
if they are not loosen the servo horn screw and adjust it as close to 90 degrees as
you can and screw back on tight.
Picture will follow next with more instructions below.
http://i32.tinypic.com/2enp4xc.jpg
At the center of this picture shows the 90 degree angle your swash plate should be
set at once it is set properly... Swash should be as close as possible to 90 degrees
from the main shaft looking both from the rear/front of the helicopter as well as from
the side... Once it is set this way it will hover with no drifting...
To get it at 90 degrees its very simple.... Looking from the back of the heli. Left servo
is your Elevator Servo...
A. Turn out (unscrew) to lengthen the rod making the swash plate tilt forward
or
B. Turn In (tighten) to shorten the rod making the swash plate tilt Backwards
Same goes for your Right servo (looking from the back) Which is your Aileron...
C. Turn out (unscrew) to length the rod making the swash plate tilt forward
(YES I SAID FORWARD)
or
D. Turn in (tighten) to shorten the rod making the swash tilt backwards
(YES I SAID BACKWARDS)
This is not your typical 3 servo swash where things are nice and neat
so yes each servo actually tilts the swash up and back from its position
in one corner at the ball.... which is why i said tilts foward/backwards so
you can grasp the movement better.
That being said, if the swash tilting backwards after the cnc upgrade
which it will because the CNC swash balls sit higher than the stock you
will need to adjust both links gradually at the same time, at equal turns.
I have found that 6 turns out on both servo arms brings it level, maybe
different on yours.. you dont have to keep clicking the ball ends onto the
swash balls each time, simply position them both against the balls with some
pressure and you will get a good view if you have to move them in or out more..
Do this until it looks pretty straight at 90 degrees..
Then click on the arms to the swash... turn on TX and do a test flight....
CNC Swash is much more sensative than the plastic low tollerance "Thing"
that was in there so dont go panicing if it vears a bit... in other words dont
take it slow and go up slowly get up there to 3 ft quick and see what it does
with no stick (Cyclic) movements....
If you eye balled it correctly it should hover just fine with very little
forward/backward or side to side movements... any movements that may
happen you cant just jump to the conclusion that the swash isnt set right.
1. is there a fan on in the room?
2. is there an a/c vent blowing in the room?
3. are you hovering over obsticles or too low??
if no to all 3 questions up there, then OK you can say its not set perfect yet...
try getting rid of the movement by using the servo trims.. once you get it
trimmed out.. leave trims as is and bring it down.
Now look at your trims....
Hmmmm aileron trim is to the right, meaning its compensating
for Left aileron...
This means swash is leaning too much to the left looking from back...
meaning the right servo (looking from back) needs its servo arm
shorted a tad bit (depending on how much you had to compensate
with the trim.. i find 1 turn for every 2 lines on the transmitter trim is correct)
Same for if trim was to the left just visa versa (lengthen right servo arm)
Same for Elevator, if trim is up means you need to lengthen servo arm on
left servo and if trim was down shorten the left servo arm.
once you made those adjustments the amount you think it should be set
the TX trims back to zero again and test...
And this is how it goes..