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 28, 2008

Fuselage - sanding and varnishing

Sanded and varnished today! Lots of it. Six hours worth. Whew.

The lower longeron that was varnished the last time was sanded with 220 grit today and given two more coats of epoxy varnish. It gave the ash a beautiful golden shine. Pretty neat looking.

Here, Brighton came to check on the progress. Think he wanted to help? What 2 yr. old wouldn't?

Station 4 Verticals were also sanded and given two more coats. You can see the color difference between the ash and the spruce.

A bunch of other Verticals and Horizontals were also sanded and given a first coat.

More sanding. More varnishing.



Wednesday, July 23, 2008

Routing the longerons

The fuselage was broken down completely in preparation for varnishing. It felt kind of funny - this big, wire braced fuselage which you worked so long building was reduced to a pile of sticks, a box of fittings and a pile of wires.

Such is progress.

Graham and I routed the lower longerons today. I borrowed Walter Ivey's 1/2 in shank plunge router (mine was 1/4 in) and used a 3/4 in wide bit purchased from Woodworkers Supply.

The depths of the routs varied from 1/8 in. deep behind the splice to 3/8 in deep at the tail post. In essence, the "I" section got thinner towards the rear.

Here's a sample of the longerons. Next step is to sand them, varnish tham, and add the copper end.



Thursday, July 17, 2008

Elevator Yoke

While waiting for the spruce order to arrive for the floorboard area, I decided to clean up the original elevator yoke. This piece mounts behind the rear seat. The control stick moves this yoke whose ends pull on the respective elevator cables. This is an original Jenny piece that I got from Robert Summers in Ohio.

The yoke only came with one bearing, so another had to be made.

Some 1/16 in. flat stock was bent around a 1 in. tube.

And the ears were bent out....

...ground to shape and drilled. There is a small hole in the top for lubrication of the bearing.

Everything was brazed together.

Bead blasted, filed and primer painted. The original is on the left.

Then the yoke was painted. The original wood will be given a coat of varnish in the future. You can see the broken arm in the center of the tube. Originally, there was a ball end which attached to the rear control stick. This has to be repaired before the part is finished. Till then...



Friday, July 11, 2008

Station 3 and 5

Station 5 was drilled to accept the fitting today. The drill jig came in really handy.

Here's the fitting in place with the AN3 bolts.

While I had the drilling jig handy, I drilled the engine bearer support brackets too.

The Hisso engine utilizes a completely different Station 3 cross member. The OX-5 versions have a really pretty hoop to span the longerons above the accessory section of the engine. The Hisso cross member angles down (where it attaches to the wooden mount) across the span, and back up to the other side. It also curves to stay out of the way of the fuel pump. So...the tube angles down, curves and angles back. Not easy to build. So, I decided to build the tube straight and weld in the curve. Here, you can see the straight tube cut out and the curved piece in it's place.

Here's the finished tube with the curve welded together. It was much easier than wrestling with a tubing bender while trying to keep everything straight.

Remember the U-bolts I made recently? They are being heat-treated right now so I decided to make the brackets that hold the U-bolts in place. I cut some 1 in. .090 square tubing until the "ears" were 3/16 high.

Here they are.

The ends were ground on the grinder and hand filed smooth. You'll see where these pieces go soon. I have to drill the holes for the U-bolts next.

Enough for one day - on a lighter note, I received some pictures from Milt Clary of Vienna Virginia. Milt e-mailed me a few weeks ago asking questions about the Jenny landing gear. He had decided to build a scale "mini" Jenny to help his church advertise Vacation Bible School in an upcoming 4th of July parade. Milt and his crew really did a great job! Check out this Jenny!

Milt decided that a Jenny "was such a historically significant airplane and intriguing to kids", He thought it was the perfect airplane for the program. Anyone interested in seeing this "mini" Jenny come to life, check out

Till next time


Sunday, July 06, 2008

Lower Spider Plate & Station 6 Transverse Fitting

Drilled the holes on the doublers today and riveted them in place.

Here's the finished plate less another coat of primer. When the fuselage is broken down for routing and varnishing, I'll weld this to the top Spider Plate and make it one.

I also finished the lower fitting at station 6. This fitting holds the transverse wires that cross the fuselage. The fitting wraps around the wooden vertical piece (you'll see what I mean in a minute) incorporating two 45 degree bends.

I was able to make both bends in the vice. The first bend was easy. The second bend needed the help of a bending block. It sure would have been easy to just make one 90 degree bend, but then the fitting would have a gap across where the vertical piece was routed and that would bother me.

Here's the finished piece after the doublers were brazed on the inside.

Here's the fitting in place awaiting the final drilling. Till then...


Saturday, July 05, 2008

Spider Plate and Wobble Pump

Welded the lip on the lower Spider Plate today.

Next step is to rivet the doublers in place.

Here's where they go.

Lastly - my friend and fellow Bucker Jungmann owner John LaBarre sent me this D-11 wobble pump. Since the Hisso carburetor is higher than the bottom of the fuel tank, the engine will not gravity feed. Originally, they solved this problem by -

1.) pressurizing the fuel tank with an air pump.
2.) install a header tank in the center section fed by a mechanical (or wind driven) fuel pump.

I really don't like either of these options. The thought of a fuel tank under pressure, ready to burst, does not thrill me. I think the header tank looks awful.

So, I'm going to put an engine driven fuel pump on the back of the Hisso, and use this wobble pump as a backup. I think the Old Rhinebeck Jenny uses this method.

This pump is in great shape, but in all likely hood, it should be overhauled. Does anyone know a place that overhauls D-11 pumps? They seem like simple creatures. Anyone take one apart themselves and do the same thing?

A hearty thanks to John LaBarre for the pump.

More tomorow


Thursday, July 03, 2008

Lower Spider Plate

Cut the lower spider plate bottom curve today. I used the bandsaw to get the rough outline and the hand grinder to cut to the line.

Here's the plate cut to size.

The radiator support is a piece of steel strip welded along the lower curve. I used angle brackets to hold everything in place....

... and clamped it all together ...

...and made a few tack welds.

The finish welding will be the next step. Enjoy


Tuesday, July 01, 2008

Lower Spider Plate

All right, the stone fireplace is taking longer than I expected and I needed to work on the Jenny a little bit before I lost my mind!

The Hisso installation has posed it's own set of challenges. As far as I know, there are no drawings for the Hisso spider plate, thus I used an OX-5 spider plate for the top half and made a custom support for the lower half. I have lots of pictures for this (for originality) but no real drawings. It would have been nice to plug the coordinates into a CAD machine and cut out a precise arc to the lower plate, but I wasn't sure if it would match up with the radiator - of which we had no drawings either - so we have to do this manually.

Here's what I'm talking about. I had the lower plate cut out on the water jet cutter, with the top, sides and bottom generously enlarged for the unknown curveature of the radiator.

The excess metal on the top was bandsawed away to meet the top OX-5 spider plate.

Like this. Eventually, these two pieces will be precisely fit and welded together. This was the first rough fit.

There will be a layer of felt between the lower plate support lip (to be installed next) and the brass radiator. I'm guessing the felt will be about 1/4 in. thick. I traced the outline of the radiator on the back side of the plate, allowing room for the felt and the doublers.

Next step: cut the arc and weld the 1 in. lip to support the radiator. Hope to do that Friday. Till then...