Dual Elevator Servos - Servo Extension Question

[Gord Silver]

Hi Keith:
           Had the same problem when I started flying my
first Nova 2+2.
           I ask the JR rep. at Toledo, and he claimed he
used extensions up to 60" with no filter. Up to that point I
was having the extra long extensions made special.
           The one thing you do have to do, regardless, is
twist the wires, or you'll loose range. An easy way to do
this is, clamp one end on your bench, and twist the other. (
approx. 1 turn, per 3". ) Clamp the other end, and run a
heat gun over it to set the twists.
             Have a buddy who's very particular and neat,
who was having trouble with range in his first 30% ??????.
Checked his ext., and sure enough, straight as an arrow down
the inside of the fuse. Took them out ,twisted them, and he
went flying. ( something I would like to do right now, but
we got 5" of the white stuff last night.)
             Hope this helps,        Gord

Keith Black wrote:

> Regarding placing servos in the stab, the location I was
> planning on placing my RX (just behind the wing tube)
> would require about 44 inches of servo extension between
> the RX and each stab servo. What problems/risks does it
> present in having extensions this long? The only
> extensions longer than 36" that my local hobby shop sells
> are 48", but these have a built in filter. I really don't
> want to use a filter unless absolutely necessary, it will
> add weight. Is it really necessary to filter runs longer
> than 36"? What other considerations should be made with
> long runs? Any input would be appreciated. Thanks,Keith
>
>      ----- Original Message -----
>      From: Morton
>      To: discussion at nsrca.org
>      Sent: Friday, March 21, 2003 11:35 PM
>      Subject: Dual Elevator Servos
>       Keith,
>
>      I have been very happy with 2 digital
>      programmable MCV2 micro servos mounted on their
>      sides inside the stab of my Viper 202. I
>      originally had the MCV2 superflat (11 mm) servos
>      which worked fine, but I  liked the quicker
>      speed and power of the micros, and they were
>      still only about 1 oz each. I like the short
>      positive nearly frictionless connection to each
>      elevator half (MK ball bearing clevis). They
>      have held up very well and I had no problem
>      matching the throws. I didn't even use the
>      programming feature, I just plugged each servo
>      into a different channel and mechanically
>      matched them as close as possible. One possible
>      advantage could be that you could have each
>      servo work independently with ailerons if you
>      wanted to. I do that on my fun fly plane and it
>      works great (I am thinking for a multi-purpose
>      AA plane).
>      I mount the servos on their sides to a light ply
>      and balsa sandwiched rectangular plate. I use
>      the outer balsa layer to exactly match the curve
>      of the airfoil. I then cut a hollow plywood
>      rectangle that will support the servo in the
>      stab. The width of the plywood rectangle
>      (donut)  is such that 1/2 will be under the
>      balsa stab sheeting and 1/2 is used to support
>      the servo plate, the center is cut out for the
>      servo. I then use a router to create a box for
>      the servo and mounting plate into the foam core
>      before sheeting in the stab. Glue in the plywood
>      rectangle and sheet the stab normally. I then
>      drill a hole in each corner to attach the servo
>      plate. I later added an access hatch  in the
>      bottom of the fuselage to help fish the servo
>      wires and extensions. Send me a message and I
>      will e-mail pictures if you like.
>
>      Ray Morton
>
>      Keith Black wrote:
>
>     > putting servos in the stab halves
>     >
>      This is exactly what I had initially considered
>      on my Aries so my removable
>      stab would be easier to remove. Essentially they
>      would be like small main
>      wings.
>
>      However all the feedback that I received seemed
>      to indicate that this was a
>      bad idea due to extra weight, possible
>      differences in throw over time, etc.
>
>      I'd like to hear pros and cons from others that
>      use used this technique.
>
>      Thanks,
>      Keith
>
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