How to build a double-tapered balsa wing (50" span, .45 size)

[Frank v B]

Finishing the bottom of the wing:

- added the blocking for the wing hold-down bolts at the trailing edge.
- added balsa behind the leading edge to add beef for the dowels.
- went over all the joints.  Any gaps I slipped in 1/16" balsa and added some glue.
- added the leading edge and trailing edge sheeting.
- added two shear webs at the end of the landing gear plate.  Just to make me feel better.

Cannot do the centre sheeting yet until after the servo installation.  Since this plane has elevons (no elevator) there will have to be two servos.  Plan to bury them in the wing....somewhere.

Frank

[Frank v B]

Installed the aileron servos.  Just epoxied them to the rib.  Then glued braces between them to add strength. 
In case you are wondering about the code: F=front R=rear P=port S=starboard.

Added the extra leading edge to make it to the proper 1/2".  Added 1/4" balsa to the front of the false leading edge.

Frank

[Frank v B]

Shaping the leading edge.

step 1- draw a line (red) down the leading edge of the wing where the high point should be. Red line on the wing photo 51  See plan outline shape. (photo 55)
step 2- plane and sand up to the line but leave it in place. See actual profile in photo 54.

Also photos:
- sheeted the centre section on the bottom around the aileron servos. Photo 52.
- the planing caused this dirt in the garbage can- from one leading edge.  Photo 56. Still one to go and two trailing edges.

Frank

[Frank v B]

Building ailerons and wingtips

Ailerons. 
I cheated.  Instead of sanding/planing an angle on the underside, I glued tri-stock to the aileron and pinned it in place for the glue to dry.  It was done in 5 minutes.  When the glue is dry, I will sand the the excess off the bottom (it sticks out) and sand the edges.

Wingtips
My preference is to have the ailerons protected on the outside by the wingtips.  The plans show the ailerons ending at the tip.  This can cause flutter.  Made the wingtip 2" longer than the chord of the tip rib.  Glued it in place with 5 minute epoxy.  Tomorrow I will finish the shape (teardrop) and handle the reinforcement.

Frank

[Frank v B]

Tips
- Added scrap aileron stock to make it stronger and thicker.

Cap strips
- added cap strips to all the exposed top ribs.

Ailerons
- installed the aileron hinges in matching slots in the aileron stock and trailing edge.  Used plastic Klett hinges.

Frank

[Frank v B]

Final touches:

1) make the ailerons thicker- the trailing edge of the wing was thicker than the leading edge of the aileron.  I added a piece of 3/32" balsa on the bottom of both ailerons.  Note that I pinned the aileron to the board first and aligned it with a steel ruler so it would remain straight while the glue dried.
The glue used was 15 minute epoxy.  Carpenter's glue would have soaked the wood and curled the aileron.

2) build up the wing tips.  Still needs a final sanding.

Frank

[Frank v B]

First peek. Attached the wing/wing dowels and screws, ailerons and sanded the wing.

The prop/spinner is put in place so you know where the nose is located.
This does not have an elevator/stab at all.  Just a fin/rudder to come.

Mark was aiming to build something that looked different.  He sure got it.

Frank

[Frank v B]

Fibreglassing the centre section.

Epoxy was watered down 50/50 with denatured alcohol and brushed on.  The consistency was like water.  Quick and easy.  The fibreglass is very light 2/3 oz. cloth.

First Coat:  Put on about a 4" ribbon around the wing, brushed on the epoxy with a 2" wide cheap brush and am letting it cure.  First two pictures.

Second coat- will be an 8" wide ribbon all the way around to stagger over the first coat.  3rd photo.

Note- covered up the wing bolt holes and the holes for the leading edge dowels (removed).  Easiest to cut the holes with an #11 blade after the glass has cured.

F.

[Frank v B]

The wing is now finished enough to set aside for the covering stage.

The aileron hinges are in their slots but will not be glued in until after covering.  A neater finish.
THE aileron control horns are installed after covering.

Now back to the fuse. https://temac.ca/smf/index.php?topic=8920.0

F.