Are
you grounded because of a stripped servo and hate to
have
purchase a
whole new "brick" for your ParkZone Servo on your Sukhoi, Vapor, Ember,
Ember2,
Citabria, Centurion or the E-Flite Blade mCX?
This repair applies to: a
stripped servo on the ParkZone Vapor, Sukhoi, Ember, Ember2, Citabria,
Centurion and the E-Flite Blade mCX.
These micro receivers have evolved some since they were first
introduced but the servos are now completely interchangeable.
That's right a
Vapor or Ember servo will work on an E-Flite Blade mCX and vice versa.
They may be made
from
black or white plastic but now they measure dimensionally exactly the
same.
Caution - These components are tiny and can be damaged easily (maybe
limit your coffee intake) but not to worry, if
you do need to replace the servo there's a replacement so you
won't need to purchase the whole receiver brick.
Work
Area
It's best to work over a soft white surface or disassemble inside of a
clear plastic bag. These small parts will bounce and disappear. They
can be lost very easily.
I've done this way too many times!
Even
though
the "brick" electronics are different on the ParkZone Vapor, Ember,
Ember2, Citabria, Centurion and the E-Flite Blade mCX.
The servo
repair
is the same.
First -
Remove the receiver from your plane or helicopter
then let's remove the servo.
Note
the 2 different size of screws, this is common with the
servos. After disassembling several hundred bricks there seems to be no
discernible pattern or consistent locations
(This makes me nuts!)
Next, if the servo motor works it is best
NOT to replace it. Actually
it is best not to get a standard soldering iron anywhere close to the
"brick". See the graphic below:
There
is a tiny diode between the rudder
servo leads. The heat from a standard soldering iron will soften the
solder
at both ends instantly. Then the surface tension of the liquid solder
on
your iron will suck the diode completely off the board and it will
become lost in the solder on your iron, even a very small amount of
solder!
Instead,
just remove the servo motor from the housing. Gentle here, the plastic
can break easily .
A
gentle
nudge should move it out of the housing.
Remove the
end retainers and unscrew the threaded rod from the the
servo "arm".
Note
the location of the two rubber O-rings used to cushion the
movement.
Careful here, the rod is soft and
easy to bend
(as
you can
see with this bent rod).
The gear is
only pressed on.
I
place a drop of thick Cyanoacrylate on a piece of wax paper. Just
touch the end in the glue then press back into the gear. Make sure not
to get any glue on the threads
Be
sure to let the glue set.
We've tried many coatings
for
the next step, like wax, mold release, light oils, vaseline etc. .
.and now we have many
permanently glued unusable parts.
We found that by far vasiline is the best.
Once the glue is completely cured, coat the entire shaft
and gear with a THIN
coat of vaseline.
Coat
the servo arm with vaseline, be sure not
to get
any inside of the threaded area.
Fill the whole we are rethreading with thick cyanoacrylate and insert
the vaseline coated all-thread rod.
Be sure it's aligned properly then set aside to cure.
Once cured, run the all thread its full length several times
to re-tap the threads.
Once it is threaded it should move
very freely.
That's
it - a
complete set of tough new Cyanoacrylate threads.
Reassembly
is simple. Here you can use a VERY small
amount of
lubricant, but on the rod only, not enough that it will drop onto
the board below, then be sure to replace the O-rings.
Note
the direction the arm is placed. If it is reversed it will work,
but it will not center at the same location on the board.
Snugly
press the two retainers in place. If you have lost a retainer
you can use insulation stripped from a small wire.
Be sure you have
free rotation but with very little linear movement.
Below is a
fix for nervous servos also!
The
next few
steps can be used to help if you have slow, jittering, unable to find
neutral or nervous
servos on your Parkzone Servo for the Sukhoi, Vapor, Ember, Ember2,
Citabria,
Centurion and the E-Flite Blade mCX.
The
servo measures resistance between these two bands with the
"fingers" on the arm to find it's
location. Since most lubricants have some conductivity this can result
in inoperative, sluggish (especially in cooler
weather) or nervous servos (it
is unable to
find the right
resistance for it's location). I recommend that
you clean these strips
and not allow any lubricant or anything else to drop onto these.
I
use denatured alcohol and a Q-Tip to remove any oil or dirt. I've
seen some use a rubber eraser although I would be cautious about
damaging or removing any material from these strips.
Next
carefully bend the "fingers" up to get a positive seat on the
bands.
OK, time to put it all back together.
Reassembly
is simple - just watch the servo screws, they can be stripped easily
- if that is the case the servo may lift off
the board and restrip the servo again.
Try a tiny drop of thick
CA in the screw holes, then when
partially cured use a needle (coated
in vaseline) to reopen
the holes so that the screws can
be rethread into them. Be sure to remove any cured CA from the bottom
of the
servo so it will seat down on the board properly.
Do
not
install until the CA is cured completely.
Very
Important - Do
a
visual check of the receiver wiring - the motor leads &
especially the battery leads, where they are soldered onto the
reciever will often wear from moving the wires while you
plug the battery in.
This will eventually break a few of the small copper strands in the
wire where the solder ends.
This board is so small sometimes a single small strand can make its way
over to the opposite lead causing a short circuit. This will damage the
circuit and the entire board will have to replaced.
Be sure to resolder or secure
those strands!
|
Everything
Good?
Great!
Go ahead and
power everything up. Check for free movement of the servo and watch for
excessive linear movement, snug up the retainers if the rod
moves too much!
Now it's time
to re-install the receiver into your plane and go fly!
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