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Member Projects => Fraser's Project Board => Topic started by: Gearup on October 11, 2023, 04:28:06 PM

Title: Cessna 140A Project 5
Post by: Gearup on October 11, 2023, 04:28:06 PM
Cessna140A project in parallel with four other light aircraft models.
Title: Re: Cessna 140A Project 5
Post by: Gearup on October 12, 2023, 03:26:10 AM
cherry wood
Title: Re: Cessna 140A Project 5
Post by: lastvautour on October 13, 2023, 10:43:32 PM
The 120 and 140 are among my favorite high-wing wonders.

Lou
Title: Re: Cessna 140A Project 5
Post by: Gearup on October 16, 2023, 04:20:57 AM
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.
Title: Re: Cessna 140A Project 5
Post by: Gearup on October 18, 2023, 06:19:00 AM
Cutting the slot for the horizontal stabilizer..
Title: Re: Cessna 140A Project 5
Post by: Gearup on October 31, 2023, 11:13:27 PM
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.

Title: Re: Cessna 140A Project 5
Post by: Gearup on November 08, 2023, 12:41:38 AM
Cessna140 ribs marked out. Now onto the empennage.
Title: Re: Cessna 140A Project 5
Post by: Gearup on November 09, 2023, 10:12:28 PM
Primed. Typical ribbed flight control surfaces of early light planes. 
Title: Re: Cessna 140A Project 5
Post by: Gearup on November 13, 2023, 01:55:04 AM
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.
Title: Re: Cessna 140A Project 5
Post by: lastvautour on November 13, 2023, 10:48:44 AM
Nice to see them all come together.

Lou
Title: Re: Cessna 140A Project 5
Post by: Gearup on December 27, 2023, 12:26:59 AM
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
Title: Re: Cessna 140A Project 5
Post by: lastvautour on December 27, 2023, 10:56:51 PM
I know I am just repeating myself, Excellent-


Lou
Title: Re: Cessna 140A Project 5
Post by: Model Maker on December 28, 2023, 11:35:03 PM
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
Title: Re: Cessna 140A Project 5
Post by: Gearup on December 29, 2023, 06:56:54 AM
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..
Title: Re: Cessna 140A Project 5
Post by: Gearup on January 11, 2024, 01:01:38 AM
wings and tail glued. 
Title: Re: Cessna 140A Project 5
Post by: Gearup on January 17, 2024, 04:46:34 AM
Filling started. As the 140 was a fast back fuselage, the simple flaps ended square to the side of the cabin. A lot easier to fill on this design.
Title: Re: Cessna 140A Project 5
Post by: Olli on January 17, 2024, 08:55:44 AM
You are perfect with wood
Title: Re: Cessna 140A Project 5
Post by: Gearup on January 19, 2024, 02:27:58 AM
I do enjoy working with it.
Title: Re: Cessna 140A Project 5
Post by: Gearup on February 06, 2024, 03:52:22 AM
Major filling done and cooling inlets and carb inlet carved. The Cherokee had a rather more rounded nose than the other aircraft I'm building. The close up picture do show more finessed cleanup of the inlets is in order. But, consider the hole for the prop is only .062" in diameter.

++++Minor detail+++++. This is the Cherokee 140. Now why did Piper name it a 140 when Cessna already had the number. Hmmm. Ill leave the picture here and remake the post to the cherokee page.
Title: Re: Cessna 140A Project 5
Post by: lastvautour on February 07, 2024, 10:19:43 AM
That is fantastic Fraser. I never went beyond painting or using a decal for the intakes.

Lou
Title: Re: Cessna 140A Project 5
Post by: Gearup on February 07, 2024, 05:06:13 PM
Interesting. One of the first things my eye goes to is the intakes on an aircraft. I guess they are like a nose or mouth on a face, each one is different and characteristic of the person ( or airplane).😀

Fraser
Title: Re: Cessna 140A Project 5
Post by: Boomerang on February 16, 2024, 08:40:35 PM

 I work on if my eye is drawn to a detail I will attempt to replicate it.

 Looking good Fraser

 Gordon
Title: Re: Cessna 140A Project 5
Post by: Gearup on February 17, 2024, 01:09:07 AM
True for me too. Thanks.
Fraser
Title: Re: Cessna 140A Project 5
Post by: Gearup on March 31, 2024, 02:09:44 AM
Proper picture of the Cessna 140A. 

I think for the carburetor I will build it up with silver tape as it does sit forward slightly from the cowl. 
Fraser

Title: Re: Cessna 140A Project 5
Post by: Gearup on March 31, 2024, 02:58:47 AM
Showing the completed gear for the Cessna 140A

A .020" wire was run into a 1/8" copper tube as in the Piper main gear, and squashed down. The aircraft is a flat spring steel gear leg, so this worked well. The .062 axel was slipped onto the protruding wire and bent to the correct angle. A solder blob on the joint made for a very strong gear. 

The tail wheel bracket was made from 1/4" brass tube squashed to make it flatter then shaped on the belt sander. It took a few tries to get the geometry right and the piece is only 1/4" long. The tail spring was soldered and will be trimmed later. For scale the tail spring rod shown is .062" diameter.
Title: Re: Cessna 140A Project 5
Post by: lastvautour on March 31, 2024, 06:08:04 PM
Nicely done.

Lou
Title: Re: Cessna 140A Project 5
Post by: Gearup on April 02, 2024, 12:40:59 AM
Thank you.