KING ALTAIR

Building Details for a Plug in Wing

I found that a 80 inch wing was a big problem for me to safely carry it to the flying field in a Toyota Camry.
After thinking about it for awhile, I came up with what I believe is a reliable plug in wing system for the
King's 80" wing. The following photos depict the steps I used to create the plug-in system.

  

    

The above views show the landing gear block(s)- I used two blocks stacked to strengthen the gear box. The trial servo mount- Construction of the balsa wing receptacle. Preparing to cut the bottom side of the wing to accept the Receptacle.

   

In the foreground are the 1/32 plywood rib reinforcements that go around the receptacle box. (use scrap from the kit) The ribs W-1 through W-4 have been cut to accept the receptacle box. Next the 1/4 inch 5 ply plywood dihedral brace is cut. The length of the plywood dihedral brace is 16 inches long. The receptacle box inside surface must be free of cement and obstructions. Be sure that the brace fits snugly without binding before it's glued in place. Likely, you will have to sand the brace for a good snug but free fit.

 

Make a receptacle box using two each 1" X  1/4" hard balsa sticks and two (top & bottom) using 3/4 X 1/4" balsa strips as shown.
You will have an internal receptacle measuring (1/4" wide by 1" high) for the wing dihedral brace. Each wing half box is 8 inches long. Use 1/4"thick by 1" high (5 ply) plywood and the total length will be 16" long. See the photo above. Cut the plywood angle to reflect the desired dihedral . I used 2 1/2" inch under each wing tip. The original wing has 31/2" dihedral under each wing tip but I wanted a little less dihedral for my wing. I reasoned with newer proportional radio equipment (not reeds) less dihedral would provide enough lateral stability.

TheBOX (receptacle) extends from the root rib W-1 to W-5. W-5 is not cut, the box butts against W-5 rib. The landing gear hardwood mount also begins at rib W-4 and has 1/16 plywood doublers on the rib cutouts for additional strength in this area. This helps provide a good strong support area for the wing dihedral box.

Make sure that the Box is square with W-1 and is exactly the same on both wing halves. When I built the wing halves, I did not glue W-1 in place until one of the last steps. You can make the box cutouts on both W-1 ribs before gluing in place and that will help get the location of the dihedral box started correctly. Later, W-1 ribs will be glued in at an angle to reflect the dihedral of the wing when the two halves come together. I reccomend cutting 1/32 plywood braces that go around the dihedral box (W-1 to W-5 receptacle) for additional strength to the ribs W-1 through W-5. Also, use 1/4 balsa gussets from adjoining ribs to the box for additional strength. See photos.

   

This view shows the box installed in the bottom side of the wing panel. Note the 1/4 inch triangle braces to reinforce the "receptacle box".



    

Trial fit everything together. Rib W-1 on each wing panel can be cemented to reflect the dihedral angle. Assembled wing panels.

 

   

   

Optional: The root rib W-1 has a 1/32 plywood (scrap) cemented to the outside of the rib. This provides a smooth clean appearance with only the dowel hole and the dihedral brace cutout showing.

 

Both wing halves are mated together using the 1 inch by 1/4 inch plywood dihedral brace. After alignment is set up between the wing halves, use a 5/16 dowel at the trailing edge of W-1 rib for alignment (the hole already exists) and adds stability of the wing halves. See the photo above.
Next, make a copy of the root rib on drawing mylar or other transfer material, then trace W-1 rib and cut it out to be used as a pattern. (Add 3/32" to the outside of the rib pattern) From the pattern, cut a root rib using 1/32 plywood to cover the balsa W-1 rib. There is enough 1/32 scrap in the kit for all the various little parts described above.

Remember, add 3/32" to the rib perimeter to compensate the sheeting around W-1 rib.

   

This view shows the rear 5/16" alignment dowel that positions the wing joint to privent twisting between panels. Use existing holes in ribs for the dowel as well as the recptacle for the dowel.. Use 3/32 ply and 1/4 balsa for reinforcment around the dowel and the receptacle. Next, begin thinking about routing the servo wires and the exits for the finished wing.

 

   

   

Wing Chin

I made the wing "chin" using several 3/4" X 1/4" thick stock pieces glued together. First, get the airfoil (taken from the plans or root rib) to make a pattern for the other pieces. Since the wing has to be separated at the center, I found it much easier for me to make a good separation line using this method rather than try to cut a balsa block in half. See the photos above.

Of course it's important to transfer the hole location information from the fuselage former F-2 to locate the dowels in the wing. I made a wooden pattern with the hole location and placed it on the wing L.E to use as a drill guide. The dowels hold the front portion of the wing and the 1/4-20 threaded wing bolts at the trailing edge of the wing hold the wing securely in place.

 

    

   

 

FINISHING UP THE WING CONTRUCTION

AILERONS
Cutting the ailerons from the wing. This is a bit tricky, so care should be used when laying out the wing to "saw" out the ailerons. A mistake here can damage a good wing panel requiring repair later.

From the plans, I used the 2 1/2 inch measurement from the trailing edge on the inboard aileron section. The outboard aileron is also measured from the trailing edge of 1 5/8 inches. A line drawn from the inboard mark to the outboard mark defines the area to cut out. Note that this line which will be the aileron hinge line is perpendicular (square) in relation to rib W-3 so mark the other side of the wing the same way.

I used a straight edge taped to the wing panel along the line just defined. Start the saw from the wingtip (outboard) section providing you haven't glued the wing tip blocks on yet. Be sure that the saw is perpendicular and the cut follows the line on the the top and bottom of the wing panel. Go slowly, take care while cutting each rib.

Another method of cutting the aileron out using a razor or X-acto blade following the straight edge on both sides of the panel.. Cut through the wing sheeting on both sides of the wing. When you come to the ribs, go slowly and you can cut fairly deep into the ribs with the razor on each side of the wing. Remember, this isn't the final size of the aileron, it will be cut down even more preparing it for the leading edge of the aileron. However, this is the final size for the wing cut out, so take your time.

After the aileron is cut out, clean up the wing panel and add support where you will be gluing in the hinges. See photo. I used three (3) hinges on each aileron and glued in 1/4" X 3/4" scrap, this will support the aileron hinges. The 1/8" x 1 inch stock is then attached to fill in the aileron cut out.

I used a little different method to make the aileron leading edge. The kit suggest using 3/8" X 1" stock for the leading edge of the aileron. I don't have a router to accurately make the beveled cuts on the 3/8" X 1" stock so I tried something a little different and it seems to work well for me. The 1" X 3/8" leading edge can be sanded to a rounded shape rather than a beveled shape.

STANDARD METHOD After the aileron is cut from the wing panel, cut it down to accept the 3/8 X 1 inch leading edge stock supplied with the kit.

ALTERNATE METHOD An alternate method might work for you too. I cut the aileron to the following dimensions. The outboard panel of the aileron is cut to 7/8" measured from the trailing edge. The inboard section of the aileron is cut to 1 3/8" measured from the trailing edge of the aileron. Remove the excess material from the aileron leading edge and sand the surfaces so they are parallel and reasonably smooth. (The razor blade X-acto works best when cutting the aileron to these dimensions).

Note that the aileron is cut back more than it would be with the 3/8 X 1" stock.so a 1/4" thick X 3/4" wide piece of stock works well because the aileron leading edge is now 3/4" wide at this point (1 inch wide if you used the standard method)..

Add material (hard point) inside the aileron opening where the control horn will be located before gluing the 1/4 X 3/4" in place. After the 1/4 X 3/4 has been cemented in and dried, glue a 1/2" triangle the length of the aileron to the 1/4 X 3/4 inch stock. Note, the 1/2" X 1/2" :triangle stock is 3/4 inch at it's base and therefore fits perfectly to the 1/4 X 3/4" stock Sand and finish to your satisfaction then cut slots for the hinges in the center of the triangle and attach to the wing. The appearance of the finished aileron is good.

 

    

    

Completed Ailerons installed with hinges.
  
LeftTop and Bottom of left wing half.
Proposed paint scheme for the wings. This is a computer generated photo(s) that will be duplicated with dope pigment.

The following photos show the wing top and bottom paint design. Also, the Plug in Wing design. More photos are shown at the bottom of the fuselage building page.

 

  

 

Final results of the plug in wing. How it's done is shown in the instructions above.