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

Monday, July 24, 2006

Elevator fittings

Had a chance to cut more fittings on the bandsaw this afternoon.

Above is a picture of one of the curved fittings before final trimming (see the black line) and filing smooth.

Here is a picture of another fitting during the bending process. Believe it or not, I found the trailing edge of a piece of streamlined tubing worked great as a bending form. (Whatever works!) Still, the piece has to be formed by hand. Fit...bend a a little...and so on.

Here you can see all the fittings bent for both elevators.

Next shop day will be spent in front of the grinding wheel!



Sunday, July 23, 2006

Elevators and fittings

Well, I started building the elevator tabs that go on the trailing edge. Wire spans between the tabs and the control horn to give the elevator ridgidity.

First, an .063 piece of steel was bent around some trailing edge scrap. I bent this by hand (with good gloves) then finished it to shape with a hammer. Squeezing with a vise helps form the final shape.

After tracing the pattern onto the steel, the tedious process of grinding begins.

Here's the tab after grinding, filing and sanding. A hole is drilled for a AN3 bolt.

Here's the fitting after primer. The holes for the pins will be drilled later. Only two more straight fittings to make yet. Plus there are five similar fittings with an angle. You'll hear about thoes later.

As I had hoped, the brazing of the two halves went really well. (ref. previous blog). Three of the tabs are finished. Four small ones will be completed soon.

Had a chance to sand the corner blocks on elevator #1. I used the portable belt sander then finished with 220 grit sandpaper.

Here's another shot.

The status of the elevators below.



Tuesday, July 18, 2006


You know, having already made one elevator, it is surprising how easy the second elevator is going together. Guess that's called the learning curve.

Anyway, the elevator blocks were sanded to shape with a belt sander today. After that, three of the big tabs were made for elevator #2. The one with the double curve was easier this time, having made the mistakes on the first elevator! Here's a photo of the third tab being curved on a spare piece of trailing edge material. Both halves were made this way.

Then, both halves were clamped in place prior to brazing (next shop day)

Here you can see elevator #2 progress and the three tabs that were built today.



Monday, July 17, 2006


Worked on the elevator #2 today. Glued the blocks. Waiting for it to dry before sanding to shape. Spent most of the time on the next photo.

The elevator was lightly sanded and given the second and third coat of varnish. This took a while to complete as I didn't want to miss any spots. All three boys posed while the stabilizer was drying outside. Hey, it was 95 degrees today. Why not?




Finished the last two tabs on elevator #1 while waiting for the glue to dry on the other elevator. Here's the tab prior to brazing.

Then, I took a block of 1 in. X 1 in. spruce (as per the Curtiss drawings) 6 in. in length and made a channel for the trailing edge. This was done to four pieces. I used a simple Dremel tool for the channel.

Here is where the block will go. This gives the edge a smooth transition for the fabric. I measured the angle prior to cutting the block on the bandsaw.

Here's the first block in place. The block was also taper cut from 1 in. at the bottom to about 1/2 in. at the top. There are two blocks on each elevator. They will be sanded round to match the trailing edge later. Each block wil be held in place with copper.

More later.


Wednesday, July 12, 2006

Elevator construction

It doesn't look like much, but this piece took way longer than I planned! All the other pieces were simple, straight bends in the .035 sheet steel and I expected this one to be the same. But, this one was curved!

I'm sure there was another way, but I solved it by using two pieces of .035 sheet, curved easily at the top for radius and curve, then brazed everything together. Sanding and filing hid the seam.

I was not happy with my first attempt. I was so worried about clamping it tightly to the tube, that when the torch heated the metal, the clamping pressure pushed the sheet steel around the tube at the bottom end (the free ends pushed together). This changed the angle of the sheet so that it would no longer fit the wooden structure (too concave, if you imagine).

So, off came the first attempt.

From what I learned, the second one turned out satisfactorily. See below.

Here is the piece on the stabilizer. Notice the curve in the trailing edge.



Monday, July 10, 2006

Wire Bending Jig

I decided to take a break from the elevator construction to build something really usefull for the future. There are tons of piano wire in a Jenny and I read about a bending fixture in an old aviation mechanics handbook.

Needed was a 2 X 1 in. block of aluminium and a couple of AN bolts.

Here's Nathan Hammond drilling the the first hole. They are spaced about 5/32nds apart from each other. Nathan and his father have been extremely helpfull during this restoration, taking time to answer tons questions and offering help in many ways.

After the holes have been drilled, they were tapped to size. I made two sets of jigs - one with AN4 bolts (1/4 in) and one with AN5 (5/16 in) bolts. I wasn't sure which one would work best with the hard wire.

After the bolts were inserted, the heads were cut off.

Ah, time for the wire. I purchased the piano wire from MSC in small spools. If you ever had a chance to play with piano wire you'll understand - it's rather "mean" to work with! Bending it has been fun to say the least.

First, a "U" is bent in the wire.

Then, the wire is flipped over and bent outwards.

This forms the loop to hold a shackle or turnbuckle. All you have to do now is push the ferrule up, cut off the end and soak with solder. The ferrule issue will be addressed later. You have to get a spring company to make them and we are in the process of doing so.

It was good to take a break from the elevator. You'll see more about this when the tail wires need to be made in the future. Perhaps there is a better way to make wires, but for now, this works for me.




Elevator metal construction

Began working on the metal tabs on the first elevator. This one is at the main spar. The trailing edge will be cut flush later.

Here's a tab after brazing. It's .035 sheet steel bent over a piece of trailing edge.

Another brazed tab.

Here you can see the tabs on the elevator. I have a few more to build tomorow. Middle son Nicholas is supervising.



Saturday, July 08, 2006

Elevator construction

As per the last blog, the corner blocks were shaped with a belt sander today. Steel tabs will be brazed on the trailing edge eventually. More pictures of this later.

Then the control horn blocks got their plywood reenforcement. See below.

Bansawed to shape, sanded to the line and glued in place.

Clamped until tomorow.



Friday, July 07, 2006

Elevator blocks

Built a bunch or elevator blocks today. Below is just an example - when finish sanded to shape, there will be a metal fitting attached here with an elevator brace wire.

Here's a picture of the elevator control horn attach blocks (with an original control horn as a pattern). I still have to put the 1/4 in plywood gussetts on the top and bottom. These blocks also taper to fit the profile of the rib!

Also, the ribs for the second elevator were dry, so here it is! There is much more trimming and fitting to be done. Also, you can see some of the gussets in place on the first elevator.

More blocks to build tomorow. See you then.


Wednesday, July 05, 2006

More elevator work

It's amazing how three hours can go by and all you accomplish is a bunch of little things....The second elevators had the cap strips glued, nailed and clamped today. Here's the result waiting to be cut and fitted to the spar.

Also, the cross braces were cut from the 1/4 in Finnish Birch sheet. A lot of time was spent cutting and fitting the wooden blocks where the elevator control horns will attach. You can't see them here, but I hope to have them glued on during the next shop session.



Monday, July 03, 2006

Elevator construction

Trailing Abby! The family dog supervised the first fitting of the elevator today. I was pleased with the fit. Lots more to do yet, but a good start.

Began construction on the second elevator. You can see three of my favorite tapered ribs.

Here's another shot of the elevators.

Have a good 4th of July!



Sunday, July 02, 2006

Elevator ribs and assembly

I found it easier to build each rib individually, considering the taper. Only three ribs per elevator! Two are the same. One is different.

Once the glue was dry, a 3/8 in hole was drilled for the trailing edge tubing. Cut square to fit on the band saw.

After the 1/4 in capstrip was glued and nailed to the front spar, the end taper was created with a portable sander. Here's the end being formed.

Trial fit. Still have to sand the bottom.

Another look at the rough shaping.

The entire elevator was assembled today. Interestingly - as said in the previous blog - because the rib tapers (largest in the center of the elevator - 1 3/8 in) you have to shim the rear spar 1/4 in and make sure the trailing edge is 7/8 in high (if you built the rib correctly). That way, the center line of the rib extends to the center of the spar (forward) and the center of the tubing (rearward). We want everything to line up straight!