aeajr

My Feedback: (2)

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

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...I=LXVK55**&P=7
http://www.greatplanes.com/airplanes/gpma1045.html

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 to
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
well.

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
satisfaction.

I hope this solution helps someone else.

Shuttle RG

Do you happen to have any pics of this mod? Sounds like a great solution. Since this is an old thread, do you still have the plane and is your mod still in operation?

Thanks!

aeajr

My Feedback: (2)

These photos show the servo in the wing, the uncovered wing and the wires coming out of the bottom of the wing panels.

MinnFlyer

My Feedback: (4)

Ummmm....

You realize of course that you have severely compromised the strength of your wing tube by drilling a hole in it.

Now, I'll admit that I'm the first guy who will do something out of the ordinary and say, "No problem, it'll work" - But I would never drill a hole in the center of a wing tube. That is where ALL of the stress is.

Why didn't you just pull them out from under the sheeting line the Aileron servo wires?

johnboyrc

The tube is not a joiner but a outer tube for routing the string through for the stock setup of the spoilers.

The stock setup of the spoilers works fine once you set it up. Having the spoiler servo up front of the fuse helps cut down lead needed, unless you really want more ballast. Hooking the spoiler strings up is quick and easier than hooking up servo leads.

aeajr

My Feedback: (2)

The photos are of the uncovered wings of a Spirit Select. This is how they come from the factory. That plastic tube is installed when they make the wing and is there specifically for installation of the spoiler control.

As noted above, the instructions call for a string to be run. This works well. I have my Sagitta 600 set up this way. However on the Spirit I decided to do it with servos. That works too.

I think the strings are easier to set-up. The spoilers however can actually hold the spoilers closed. You can run them on a Y cable but it is more convenient to have each servo on its own channel, if your radio has this feature. It makes it simpler to trim them.

MinnFlyer

My Feedback: (4)

Ok, whew! You had me worried there. I THOUGHT you were smarter than that.