Spoilers in a Great Planes Spirit using wing servos


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Spoilers in a Great Planes Spirit using wing servos

Postby aeajr » Sun Sep 21, 2003 7:02 pm

This is about putting wing servos in a Great Planes Spirit to manage the

In July I purchased a Great Planes Spirit Select. The Spirit Select is
completely assembled with all the electronics installed. This is my first
sailplane. One of the reasons I selected it over the Gentle Lady, Aspire and
other good first gliders is because it can have spoilers.

Here is a link to the site where I purchased it for $139 complete!
http://www2.towerhobbies.com/cgi-bin/wt ... VK55**&P=7

The plane has spoilers built in the wings, but they are not opened and hooked
up when you get the RTF or the ARF versions. In fact many people never open
them up.

I finally started to set up the servos. The instructions say to put a servo
in the fuse and run strings to the spoilers. However I wanted to put servos
in the wings for more positive management of the spoilers.

I had been fighting with the spoiler tube of my Spirit for two days, trying
to figure out how to get three wires from the wing root, through that tube, to
the spoiler box where I want to mount the servo. I did not like going down
30ga wire, as one person suggested. There had to be another approach.

Here is what finally worked and here is the key.

I tried to put thorough three strands of 24 gauge telephone solid core, that I
took out of a larger 6 strand cable. The insulation is thinner on these
strands than if you buy 24 gauge wire. But they just wouldn't quite fit.

After trying all kinds of combos, I finally used two strands of the phone
wire. To that I added a strand of 22 ga. enamel-coated magnet wire that I got
from radio shack. The
enamel is the insulation and is very thin. These three strands fit into the
tube, but I just could not push them through. You have to go through two
turns in the tube inside the wing.

Then it hit me. Lubrication. Friction inside the tube was killing me.

I used saddle soap as the lube. I took one of the strands I was going to use
and built up some saddle soap on the first 6 inches of it than used it to
slide inside the wing tube to lubricate the tube. Then I did the same thing
with each strand. This got the tube well lubed and got the wires lubed as

Now, this bundle JUST FITS, but with the saddle soap I was able to push the
three wires through the tube working from the wing root to the spoiler tray.
It took two days to get the first wing wired as I was experimenting on how to
do it. Once figure out, it took about 10 minutes to wire the second one.

I have seen other methods used but they all involve undersized wire. This way
all the wires are at least 24 gauge, though I would have happily used 26 gauge
strands if I could have found them. I am sure they would have been safe.

Now I will cut an aileron extension cable to get the two ends I need and
solder them to the wire that runs through the tube. A Y cable will connect
the spoiler servos into the receiver.

I love it when a real head scratcher gets solved. There is a real feeling of

I hope this solution helps someone else.
Best regards,
Junior Member
Posts: 17
Joined: Mon Apr 07, 2003 8:05 pm
Location: LI, NY, USA

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