Printing with Light Weight PLA

Having decided to simply glues the seros onto the wing underside I ave included a simple fairing.
 
More than jst aerodynamic it also helps to secure the servo.
For simplicity the servo wire will be taped to the wing underside.

I have also tested the 1010 mm span wing with the likely flight loads. It did not break but flexed quite a bit.
I may 'chicken out' and add a thin PLA stiffener to the underside of at least to the centre & .inboard wing panel.
 

Nothing earth shattering but the first servo is working the close fitting printed aileron.

More for my own record as just another daft idea than anything particularly interesting! 

This 1st version looks very nice. Can't wait to see how it flies!  And the weight is super-low.  We are all hoping that you have quite a few hours in the air before you are forced to 2nd version.

The adding to the face of the wing is an interesting alternative to my attempt at forming in a depression for the servo. Where are you going to run the wiring?

Taped to the wing underside.

Here is the wing mounted on the Wing Dragon fuselage.
 
Of course not yet flown, much too windy!
I do not do taped! The servo wires are simply glued to the wing underside.
 
As they a 3.7g servo with 32AWG leads they are soft and flexible so easy to glue although they were taped until the glue set.
You may also note the thin, 0.5 mm, PLA 'flange' also glued on the underside. It provides a bit more bending resistance, just in case.
The servos are on a Y lead just as they are on the Blue Dragon XPS wing and fortunately I even mounted them the same way round.
 
A significant point on a 35 meg Tx with no model memories.
For simplicity all my planes on 35 meg are set up the same. 

  

But in post #61 you said "For simplicity the servo wire will be taped to the wing underside.". Pedantry strikes again.

Fair enough. I stand admonished.
I my defence I did add it was taped to the underside as the glue dried.

After doing some strength tests it appears the limit of such a printed structure is not tension but compression. The skin buckles before it tears.
To be expected as although there is adequate of cross section area in the wing skin it is basically wide and thin. Not good to resist compression.
It could be improved by giving the skin closer support but that rapidly adds weight.

Keen to keep the wing 'just printed' I looked at creating the equivalent of a spar as part of the skin and with a structural shear web between them but still all in LW-PLA.
The first step might be considered a bit of a cheat.
Adding a series of closely spaced lines to the CAD wing sketch
 
When printed it effectively creates a 4x4 mm solid 'spar' top and bottom in the wing without changing the outer wing profile. A square section should adequately resist compression. All the filaments in each spar run along the length of the span as they do in the skin.
Using the "modify setting for overlaps" feature in CURA it is possible to add a 'truss' type infill just between the spar flanges leaving the rest of the wing with a Gyroid 4% infill as before.
 
 
It makes a considerable difference with the skin showing no signs of buckling at bending forces much greater than with the simple printed wing.
It adds 2.7 g to the weight.
I doubt doing the same for the rear wing part will be necessary so the total weigh gain for a complete "spar" wing might be as little as 12g. 
However first I will flight test the simple printed wing.
Then I might have to buy some more LW-PLA!           
 

Sorry Simon, I just couldn't resist.

Following on from jon's "servo depression" I set about the same for the second wing if it ever gets built.
 
Sized to fit a 3,7 g servo so it lies exactly flush with the wing underside..
I printed just a small portion to check it actually fitted.
 
This servo is actually the one cut out of the Lippisch wing with stripped gears. 
 

Feeling particularly "nerdy" today so expended far too much time completing the design to install the aileron servos flush with the wing underside.
A CAD view of the assembled bits that relate to the servo installation.
 
The inner wing panel has a small hole in the right place to feed through the servo wire. The centre section has a matching hole and an underside centre exit.
Looks good in theory but how easy it will be to do in reality is another matter. 
Not shown are a pair of small 'infill' pieces so only the servo arm "slot" remains open on the underside.   
 

Nice lateral thinking to get some spar compression stiffness. 

The thing that is a bit tedious about an inset for the servo is to allow access to a screwdriver in case the arm needs some adjustment.  The number of times it would have been nice to have a short right-angle screwdriver to fit into tiny spaces....  

jon
With the 3.7 g plastic gear servos I have never had to replace a servo arm, the gears strip long before the arm breaks! 
I do agree if you ever want to change the position of the arm on the spline it can be a problem with a "fixed" servo.
With a foam plane I have in the past simply gouged out a suitable long slot to get at the screw and then glued a piece of foam back in. Crude but it works.

With modern radios you don't change the arm setting, just use sub trim.