Curtiss Jenny Restoration

Welcome! We hope you enjoy following the restoration process of a 1918 Curtiss JN4D Jenny. Once completed, the aeroplane will be flown and displayed at the Candler Field Museum in Williamson GA (30 miles south of Atlanta). You can contact me below by clicking on "VIEW MY PROFILE"

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Location: Peachtree City, Georgia, United States

Tuesday, February 27, 2007

Rudder Fittings

The rudder brackets were finished today. I made these out of flat stock. A lot of time was spent on the grinder!

There are two brackets on the trailing edge of the rudder. Here are the brackets in place along with the control horn. Next step will be to make the wires and give everything a coat of black paint.



Sunday, February 25, 2007

Rudder Horn and brazing

The second rudder horn was reenforced today. I did a little research on brazing - the process itself is easy and you use a much lower temperature than welding, but be careful! If you use any clamping pressure to hold the reenforcing steel to the control horn, heat will cause the thin metal to distort. If your clamps are too tight, it will squeeze the horn out of shape.

Use the least amount of torch heat to just melt the brazing rod and let it flow.

More tomorow


Friday, February 23, 2007

Rudder Horn

Since the control horns are so long, reenforcements are added to the upper end. I made a paper pattern and traced it onto some .025 steel. This was easy to bend, and a few tapps of a hammer later the fit was fine.

The steel was then brazed into place.

More later


Wednesday, February 21, 2007

Rudder Horns

I really didn't have a detailed drawing (full sized) to know how big the rudder horns were supposed to be. Luckily, my good friend and fellow Jenny restorer Paul Dougherty measured his horns for me and came up with 10 in. from the front hole to the base and 10 3/8 in. from the rear hole to the rear of the base. With a protractor, I measured the only drawing available and came up with an angle of 83 degrees, which seemed about right.

Bet you didn't think a control horn would be this complex!

Anyway, I trimmed the bottom of the horns to match the 83 degree angle. The base was then welded (above).
Tip - put a little hole in the center of the base before welding. This allows the heated air to escape rather than blow out your last section of weld.

Here are both horns.

The horns get a 14 degree angle downward to allow the rudder cables to angle towards the fuselage. I built both horns straight. It was easier than trying to remember which horn got which angle during the assembly process. Simply, I heated the end with a torch and gave it a 14 degree twist.



Friday, February 16, 2007

Rudder Horns

And then there were two! The second rudder horn was welded, ground and sanded today. Here's a picture with the original Curtiss drawing. It would have been easier if the drawing was to scale, but it was not.

Next step is to cut the 83 degree angle on the base of the horn and weld to the lower .040 plate. Also, the rudder horn is different than the other horns because of a .020 doubler that will be brazed to the top. More later


Tuesday, February 13, 2007

Rudder horns

Back to the shop today for two hours. Had a chance to weld the spine of the Rudder horn. Remember, these are longer than the elevator horns that we made earlier. Plus, they are at a different angle!

After welding, a few passes on the grinder, hand file and sander made it smooth.

Here it is again.

Had a chance to start the second one before the kids came home from school.



Thursday, February 01, 2007

rudder bar, rudder horn and fitting

I decided to work on the rudder bar today. There were two original rudder bars with our project and when they were disassembled, I noticed that one set of hardware was cut !

The picture below shows the tube that extends through the rudder bar and into the casting. (more about this assembly later).

So, an extension had to be made. I took some .125 tubing and matched it to the original piece. Since this bar rotates in the casting, it would have to be smooth....and straight.

Here's the weld.

A little time on the grinding wheel and sander produced this.

Cut on the saw to exactly 4 inches to match.

Here's the rudder bars after some good cleaning and several coats of epoxy varnish. I kind of like the "used" new look. The above mentioned pieces fit in these holes.

Now it was time to tackle the rudder horns. They are 10 3/8 in. in the back side, which is bigger than the elevator horns. But, my jig worked fine, with a little modification.

Like the other horns, I cut the pattern out of cardboard and transfered to .025 sheet steel. One thing I did differently (I do learn occasionally) was to pre-bend the trailing edge. This gives the horn the nice rounded shape on the spine rather than two pieces of steel at a sharp angle.

I did this by shaping the edge on a spare piece of small tubing with a tack hammer.

Then the steel was placed on the jig and the trailing edge was tapped into the final shape. There's a process here - tap into shape and tack weld a few inches. Move the jig down the vice and repeat.

Here it is after a few tacks.

I'll finish welding this next week.
Also had a chance to rough cut one of the rudder trailing edge brackets. The wire/turnbuckle assembly attaches here.
Till next week