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Photo #1
The cowl framework (as seen in the last installment) has now had 1/32 ply epoxied to the forward part. The plywood was soaked in water and wrapped around a quart paint can to establish the "curl" before gluing it on. The circular piece of 1/16" ply in the foreground will serve as the backplate for the forward cowl ring, which will be built up from the segments stacked behind it. These were cut using a paper template on the scroll saw and sanded to shape on the bench sander. |
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Photo #2
My 1/4" drill is pressed into the woodworking vise. I was a little concerned about this but it didn't seem to affect the operation of the drill at all. I clamped it just tightly enough to keep it from moving. After gluing the segments together to form the cowl ring, I used a piece of sandpaper to shape it as shown. |
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Photo #3
Here's the final shape. |
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Photo #4
The ring is glued to the framework and the center plywood is cut out. Popsicle stick segments are glued to the framework to support the cowl flaps, which will be cut from thin aluminum flashing. This is the cheap variety that is used for roofing. |
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Photo #5
The lower part of the cowling showing the engine cutout and muffler. |
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Photo #6
The front part of the wing-fuse joint. See the rear part below. This is just a strip of 3/32 sheet, sanded thin at the edges and glued to the formers you saw earlier. There is no former in the center, in fact it is nearly flat at the center joint. The front fairings |
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Photo #7
The wing hold-down bolt access holes are lined with sections of the hard cardboard tubing that K&S packages and sells their music wire in. |
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Photo #8
Lightweight white water-based filler paste is used on the wing root and removable lower air scoop. |
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Photo #9
The front part of the wing-fuse joint. Note the sharp leading edge. This is a strip on the wing root LE that breaks up airflow at high angle of attack, causing the wing root to stall before the rest of the wing. The people I've talked to that have flown this model say that it works very well. In combination with the washout, it makes it hard to break the plane into full stall. It just "mushes" at low speed. |
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Photo #10
Looking foward at the wing-fuse joint and former (F10). This fairing was formed by making a wedge out of 1/2" balsa and butting the flat side of this wedge against the wing root (W1) while gluing it to the fuselage. Epoxy w/microballoons was used to form the rest of the fairing from the wing spar forward. All fairings aft of the spar are made with lightweight white water-based filler to save weight. |
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Photo #11
Close-up of wing root leading edge and rib W1. One of the wing hold-down dowels is just visible at top. |