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

Wednesday, September 29, 2010

Wire Splices and Fuel Lines

There are four cable splices made using eyelets. The technique is a little different than the splices made with thimbles, but the idea is the same. I promise I'll have more detailed instructions later, but here is the gist of a typical cable splice:

First, solder the end of the flexible cable.

Using your modified screwdriver (flattened and rounded) stick the end under each strand of wire and pull outwards.

This pulls them apart into individual strands.

Since my jig doesn't work for eyelets, I used three pieces of safety wire to hold the cable in place.

Here is the first tuck. You start with the individual wire closest to the inside. Unwind it and tuck in under the closest three wires of the left cable. Take the second wire and tuck it under the top two wires. Tuck the core cable under here too. Then the third wire goes under the first wire.

Don't worry. I'll post a more detailed example (with drawings) later. I just want you to have an idea of the splicing procedure.

Anyway, flip the eyelet over and basically do the same thing on the other side.

What you are trying to achieve is a wire coming out of each opening....except one opening which has a wire and the core wire)

Starting with the first wire to the left of the core wire, tuck the strand over the next strand and under the following one. Over, under. That is the sequence as you work your way around the wire.

After the third time around (third tuck) cut off the core. We'll talk about the core later. It does not get tucked, but rather pulled down and the other wires tucked over it. You want the core to be"burried" so to speak.

After the fourth tuck, cut every other wire. This makes the next tuck taper.

The fifth tuck is "over one under two" wires. Then cut off the excess wire.

The splice looks really sloppy and ugly at this point. Not to worry. A few minutes lightly tapping it with a rubber mallet makes everything tight.

Here is the finished splice. Learning to do this was fun...and frustrating! Paul Dougherty showed me a splice back in June and I thought I paid paid close enough attention to him, but when your teacher isn't around and you're trying the splice the first one on you own, I didn't do so well. Point being - I screwed up plenty of splices before getting one right.

Practice...think about it...practice...sleep on time it will click.

Here is the first eyelet splice on the rudder bar bracket. I don't know why Curtiss did it this way, but the rudder cables are double strands of 3/32 in. cable. The elevator cables are 5/32 in. cables and a single strand. Beats me...

I finished two eyelets that evening.

The eyelets in place on the rudder bar.

At the hangar today, the wobble pump was installed.

All the fuel lines are 3/8 in. copper tubing flared on the end.

Here is the fuel line from the tank to the wobble pump.

The line runs under the seat rail.

Clamped wherever possible.

And runs all the way to the fuel tank shutoff valve. The tubing was cut with a cutter...

...and flared with the flaring tool.

Don't forget to install the nut on the tube before you flare the end!

Here you can see the fuel line routing (without the firewall in place). There will be either strap hangars to support the line or the line will be clamped to the firewall. I'm not sure what I want to do yet.

The wobble pump-to-carburetor line was bent using a wheel from a washing machine motor. Don't laugh. My wife's washing machine broke last year and when I fixed it, I noticed that this pulley was the perfect size for bending a fuel line. Some husband I am.

Here's the fuel line in place.

It parallels the other line. More clamps will be added soon.

There you go. Hope to post more before the end of the week.


Sunday, September 26, 2010

First wire splices

After the kids finished all their baseball games this weekend, I had a few hours to splice a few more wires. Here is the 1/8 in. cable in the jig.

Looks pretty crazy, but this is what the splice looks after the third tuck.

Two finished rudder bar to rudder bar cables!

Last week, I asked Chet Peek to do some research on our Jenny. Chet has a wealth of Jenny knowledge having restored a Jenny of his own several years ago. Anyway, he said this:

The exact story of you plane is hard to follow since it was originally part of order # 20035 issued 10-8-1917 for 600 Spad XIII.

his was changed to 700 JN-4D's and later to 700 JN-4H/6H models but they were supposed to carry serials 25807 to 29058, later changed to 41411-42110.

So it is mostly a mystery, and not really important, I suspect. Indications are that your aeroplane was Curtiss built.

Our Jenny is Serial Number 6062. Thanks, Chet for the neat information.

More this week


Tuesday, September 21, 2010

Cable Splices, Throttle Rod & Coppering

Hey, I finally figured it out! I successfully made a 5 Tuck Navy Splice! It really wasn't that hard once you figure it out. Let me practice a little more and I promise I'll post step by step directions on how to make the splice.

This is where the first splice will go - the front rudder bar.

Since the paint was sufficiently dry, I installed the inter-stick pushrod.

And the rear stick pushrods.

Here you can see the rear stick pushrod attached to the elevator horn.

Took time to drill the fuel shutoff handle. A cotter key was installed thereafter.

Today, I decided to build the front throttle pushrods. I cut some tubing to size and flattened the ends. On one end, a 3/16 in. hole was drilled. On the other end, a fork was built out of some .063 sheet steel.

I thought I made the fork long enough, but the throttles have really long throws and the fork hit the mixer arm! So, I carved out the mixer arm and it worked really well. I didn't want the fork too long because I thought it would be weak.

The upper part of the arm will be used for the push/pull cable to the Hisso carburetor. Here's the front lever in place.

And the back side.

I had a little leftover time before the kids got off the school bus, so I finished the coppering on the lower left rear cabane strut.

The fuel pump bracket and the fresh coppering got a second and first coat of varnish respectively.

Also - I forgot to mention - once you finish the last tuck of the splice, rib stitching cord is wrapped around the end and sealed with varnish.

More soon



Saturday, September 18, 2010

Cotter Keys and safety wire

Last evening, Glen Marsh and Brian Eberle joined me at the hangar. Our goal was simple - cotter key every bolt and wrap safety wire around every turnbuckle. Considering how many turnbuckles and bolts were on the Jenny, we planned for a long night!

But before we got started, Brian took a few minutes to install the upper brace for the Booster Mag.

Here is how the brace attaches to the fuselage.

And the right side brace.

Now it was time to get working on the goal.

Here is Glen wrapping safety wire around a turnbuckle.

Brian doing the same on the other side.

Me too...

Around midnight, we made it all the way from the tail to the rear seat. I should have counted how many turnbuckles and cotter keys we touched, but I didn't. Something inside me didn't want to know.

Interestingly, it was nice to perform mindless work for a few hours. All three of us had a chance to chat aimlessly about whatever came to mind. Normally, I feel like I'm not very social when we get together to work on the Jenny. I'm usually thinking about how to build a part or solve a problem and I normally have a pretty aggressive shop agenda so there isn't much time for chit chat. But last evening was great.

My friend John Guttery from Fort Worth, Texas emailed me the other day. He had asked me several months ago if I knew anything about Jenny engine covers. I had never seen one nor did I think they used any. But John found these two neat pictures. He wrote:

I located the picture (attached) I had seen and haven't seen another. These are at Penn Field in Austin. The planes were from Kelly Field. Some of Penn Field is still there off of South Congress just north of Ben White if you ever have any time in Austin. It is not too far from AUS and there is an excellent coffee place there. I still wonder why they covered the engines. There is not much problem in keeping warm in either Austin or San Antonio.

Take care.

Ben Guttery
Fort Worth, Texas

Sure enough - there are engine covers on the Jennies!

If you click on the picture, it will get bigger and you can see the details.

Thanks Ben. I really enjoyed the photographs.

More soon.