Cessna140A project in parallel with four other light aircraft models.

cherry wood

The 120 and 140 are among my favorite high-wing wonders.

Lou

I flew both with 85hp (C120) and 90 hp (C140A). The 120 ragwing would outperform the 140A even with the newer all metal wing. Both were a pleasure to fly.

Cutting the slot for the horizontal stabilizer..

Note this is the piper 140 and Grumman AA5 wings shown. All wings are done the same way.

Wing is primed and sanded. Scribed the flight controls on the wing with a jig I made.

It is somewhat hit or miss holding the wing, a ruler at the correct position and operating the scriber tool. I always run out of hands at the second step.

So I fabricated this holder for a dollar store steel ruler. Drilled a piece of 1/8 x 1-1/4 inch aluminum flat bar to allow two counter sunk 10-32 screws located at about 1/2" either end of the ruler. I used brass I had on hand for the hold downs, but hard wood will be fine. Two brass thumb nuts tighten the hold downs against the rule.

Simply adjust the overhang of the ruler to the distance required and tighten the thumb nuts.  Make sure the wing trailing edge is against the bar  and under the ruler then scribe the line.

Also for marking the ribbing on the flight controls, I improved on my marking jig by adding an adjustable hold down for the wing., Only the tips are held down to secure it to a flat bar.

The whole thing is held in position by a thin stick sprung over the wing center section. Marking is done per the instructions I previously provided in the tooling forum.

Four out of five current models have ribbed flight controls. One does not...which one?

Given the number of ribs to mark, it works out to about 200 per wing. About 50 inches-whew.
Or about 17 feet total. That's why I decided to mak a better setup for the job.

Now back to work.

Cessna140 ribs marked out. Now onto the empennage.

Primed. Typical ribbed flight control surfaces of early light planes. 

Vertical fin and stabilizer flight control stiffeners marked out, fuselage filled and all parts primed. Major parts mocked up together.

Next is to mount empennage and cut the wings to fit.

Nice to see them all come together.

Lou

Got the wings and empennage pinned together on the C140A. It has simple wing flaps although they are more of a speed brake for approach. They were quite small, unlike the 150 with the barn door fowler flaps. 

Fraser

I know I am just repeating myself, Excellent-


Lou

Hi Fraser

Model is coming along very nicely!

I'm sure you have covered this before, but am wondering:

 - What material do you use for the ribs? Is it plastic strip? If so, what thickness and width?
 - What tool do you use for the panel lines? I always struggle with these, especially in pine material due to the
   different hardness of the growth lines.

-ken

The rib marking and scribing tool are illustrated in post #6 in this project. Also search" wing rib marking " and "fish hook" in the forum for other detailed info on the making of the tools. Rib marking uses a ruling pen to apply thinned carpenters glue..

wings and tail glued.