The outboard (main) panels of the lower wing are built the same way as the upper wing, with two changes. The upper panels are swept back and have no ailerons, while the lower panels are straight with ailerons cut in. Just as with the upper wing, I spaced the front and rear spars off the building board with jigging blocks, and started construction by assembling all the ribs in position on the spars.
This is the lower right panel with all the ribs assembled to the front and rear spars and the balsa leading edge glued in place.
- This is the right wingtip bow that I laminated earlier and intentionally made oversize. I have trimmed the outer ends of the front and rear spruce spars to fit against the inside of the laminate after it is trimmed to exact length and assembled in place.
- I used the plan as a guide to trim the front and rear ends of the laminate to exact length and then glued the bow in place. On an assembly like this it’s important to make sure the bow is centered vertically on the leading edge as well as the trailing end of the tip rib. In some cases a bow will be angled up or down; on this airplane it lies flat.
The trailing edge consists of an upper and lower strip of 1/16" balsa sheet set into notches already cut into the ribs. Since I am building the "in the air" with the spars jigged up off the board, the trailing edge ends up "hanging in space". Rather than cut a large piece of balsa to serve as a full-span shim, I jigged the lower sheet in place and glued it one rib at a time.
The ailerons are going to be built in place, as part of the lower panel, then cut loose. I installed the lower trailing edge sheet "full span" to provide a location reference and attachment point for the aileron ribs.
The aileron ribs are marked and cut out as separate pieces. I pinned the 1/8" balsa sheet aileron leading edge in place, at an angle, and assembled each of the ribs to it in turn.
Here all the aileron ribs are in place and, by default, are holding the aileron leading edge in position. I have added a 1/8" x 3/16" balsa strip along the top edge of the rear spar to bring the upper edge even with the tops of the ribs.
The upper trailing edge sheet is in place here, clamped with lots of clothespins. Take a look at my earlier entry on the lower wing center section to see how I beveled the rear edge of this strip before assembling it.
On the full scale Great Lakes there are LOTS of places on the wing surfaces where various struts, brackets and other fittings attach to the structure and extend through the fabric covering surface. On the model, each of these requires an insert of sheet balsa to provide a surface to support the covering around each protrusion. Along the edges of the aileron wells these are half-round shapes, which I made by cutting circles of sheet balsa and splitting them in half. In other areas of the wing there are several triangular inserts that also serve as gussets.
The engineering on this kit was not perfect. Looking at the lower wing root from below you can see a cutout behind the front spar where the plywood spar joiner - part of the center section- will fit. The problem is that ALL the ribs of that shape were marked on the printwood with the same oversize cutout. As I mentioned earlier, I found this kit at a swap meet and discoveed that "somebody" had begun cutting out parts before giving up on it. Some of that parts cutting included opening up ALL those spar notches without checking to see whether they were needed. That left me with the task of filling them, which I did by assembling the ribs as cut and then inserting short filler pieces of 1/16" balsa sheet where they were needed.