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

Sunday, August 30, 2009

Gear fittings painted

Finally! The weather cooperated enough for me to paint the landing gear (and other) parts.

More soon

Tuesday, August 25, 2009

Varnished gear struts

All the landing gear wooden parts got sanded and given a final varnish coat today. I was pleased with the results. The dozen wooden pieces next to the varnish jar are the slats for the fuel tank cradle. Since I was varnishing anyway, I decided to give them their first coat.

The langing gear struts drying in the Georgia sun.

A closer look at a front strut.

While that was drying, I drilled the fuel tank cradle straps.

Here's my pile of "parts to be painted". This should be Thursday's project.



Sunday, August 23, 2009

Gear legs with copper

Sanding...sanding...sanding. The gear legs and airfoil were sanded with 220 grit today.

After they were sanded, the first copper end was installed. I found it easier to make paper patterns first and trace them on the copper before cutting it out.

Here's the finished end. It's the top of the front gear leg.

Sorry I have nothing exciting to report, but sanding isn't exciting and I did a bunch of it today!



Friday, August 21, 2009

Varnishing the Landing Gear

The entire landing gear was broken down into its components this afternoon and the gear legs were given a final sanding. Then the legs were hung up on the rack for varnishing.

Brighton decided he was going to "paint" the parts. Luckily, I had not mixed up the varnish yet.

It's pretty neat to see the bare wood take on the amber color. I gave each leg two coats of varnish. The first coat was very thin. The second was thicker. Do you like the kids leftover halloween stickers?

Here's the airfoil getting varnished.

The parts are drying as we speak. It's amazing how that first coat of thin varnish raises the grain. When everything is dry, the legs will get coppered and another coat of varnish.

The castings John Gaertner made arrived in the mail today. Beautiful! John's work never ceases to amaze me.

Thursday, August 20, 2009

Bungee cord bracket

Finished welding the right peach basket and fitted everything together.

Here's a picture of the gear with a different pair of 26 x 4 wheels. I'm just using this set to allow me to roll the fuselage around. The other pair of wheels will be rebuilt and installed when the airplane is finished.

The last part of the gear to be fabricated is the bungee holders. I do not have an official Curtiss drawing of this part, but luckily Doc Hood made a good sketch.

This part is .070 steel cut by the water jet. The first step is to bend the ends up about 45 degrees or so.

Remember that tool I made last blog? Here is how it is used: the above mentioned 45 degree bend end is placed against the flat part of the tool and the steel is bent around the tube. (The drawing mentioned a .250 in radius which is a 1/2 in tube.)

Here it is after some forming with a hammer.

The second side is fapricated the same way. After the ends are bent downwards (to keep the bungee cords from going front and back) the piece is drilled and installed on the peach basket.

Here are the finished brackets.

While I had some time waiting for the kids to get off the school bus, I decided to see it the original fuel tank was able to hold water.

Nope! But I did locate the leaks.


Tuesday, August 18, 2009

Peach Basket Airfoil Brackets

Broke out the torch today and welded the left set of airfoil brackets. I've been taking my time with this because I wanted to ensure the airfoil stayed level between the peach baskets. After sanding away the primer, I tacked the brackets in place, reassembled the entire gear, checked the alignment and satisfied, I broke it down for final welding.

Here are the brackets after bead blasting and painting with primer.

The airfoil needed a little sanding, but for the most part, everything lined up OK.

While I was waiting for the Peach Basket to cool, I built this bending tool - just a piece of 1/2 in. tubing on flat stock. The pattern in the photo will be the bungee cord bracket. It will require some bending, so look for this tool in use soon.

Also - an update on the 3rd wing. John Gaertner started installing the rear ribs. All the internal wires have been completed.

Lastly, Phil Mintari from Texas sent me pictures of his Jenny. He moved it from his shop to the hangar so the rigging process could begin. Phil is doing a great job and I thought you might like to see this.

It's pretty cool the wonderful people you meet while rebuilding old aeroplanes. Phil and his wife Patricia are two of those people. We've swapped parts and stories and their hospitality has been second to none.

I'll keep you updated as Phil's Jenny restoration continues.

Friday, August 14, 2009

Gear airfoil cutout and First castings

Now that the airfoil had been carved, it was time to cut out the section where the bungee cords will go. As you can see, there are two angles to the cuts. After thinking about it, I found the easiest way (and most accurate blade control) was to use a coping saw.

I probably could have used the bandsaw, but I liked this method better. Even if it took longer. It worked well for cutting out the inside too.

Here's the airfoil after the cutout was removed. Of course there's a bit of sanding to do yet.

The airfoil is held onto the peach baskets with some airfoil shaped brackets. The airfoil is notched to go inside these brackets. I used a cutter on a Dermel tool.

Here is the bracket in place (to be welded later).

On a side note - the Jenny used a bunch of castings in its construction. They are very hard to find, so we decided to remake them. This has been in the works for quite some time and now the first one has been poured.
John Gaertner did the Solid Works 3D programming for each casting which was sent to a resin pattern maker. From there, John cast the first part - the piece on the tail skid that holds the bungee cord in place. Here is the process:

Making the mold using the pattern

Pouring the aluminium.


The parts after initial cleaning. There is still some maching and grinding to do, but the parts are exact as the original. Well done, John.
Also, we have contracted Dove Works Foundry in Anniston, AL to cast some of the more complex parts. They should be done in a week or two. I'll post some pictures when I get the parts.

Monday, August 10, 2009

Fuel Tank Cradle and Firewall Pattern

It was time to tackle the firewall. After studying the drawings for a while, and a frantic phone call to Paul Dougherty, I was able to patch together enough information to make a cardboard pattern.

I transferred all the dimentions from the Curtiss drawing onto the poster board with one exception - since the Hisso engine does not have any downthrust (as does the OX-5) I did not cut out the slots for the fuel tank cradle. The slots would be in the wrong location for this airplane.

Believe it or not, the firewall was a perfect fit. I have to pick up some galvanized sheet steel later this week to make the actual firewall. The plans call for 20 gauge (.035) steel.

I also made the two straps which hold the fuel tank. The material is 2 in. wide .090 strips. I found the dimentions on the drawings were very accurate. This was thick stuff, so bending took a bit of heat sometimes. The design calls for 3/8 in. strips of spruce and 1/4 in. strips of felt to screw to these cradles.

Here they are after a coat of primer. The holes need to be drilled yet, but I'm waiting for the spruce to be cut.
Interestingly - because the Hisso has no downthrust, the fuel tank does not need to be angled like the JN4 D with the OX-5. This theory was reenforced by two drawings I saw in the packet - one with the fuel gauge angled (labled JN4 D) and one with the fuel gauge straight up and down (labled JN4 D2).
The D2 was supposedly the "advanced" version of the Jenny with a Hisso engine, but never went into production. Unfortunately, a lot of the drawings are D2 prints. This frustrates anyone wanting to build a JN4D. The prints are close, but not the same as a straight D.
See, I'm building a JN4D with a Hisso, just like a barnstormer would have done in the 1920's - remove the OX-5 and drop in a Hisso - when they wanted to "soup up" their Jenny So, the firewall forward D2 information is very helpfull.

Friday, August 07, 2009

Landing Gear Airfoil carved

Well, the belt sander is back in operation. The parts came from Sears and they were installed this morning. So, the sanding operation continued. I used 80 grit paper to rough sand the airfoil shape. Take your time here. You don't want to sand too little or too much.

Once the remaining three sides were carved, the butt ends were trued on the table saw.

To form the inside curve, I used a 1 in. sanding wheel on a hand held drill.

I put the peach basket brackets in place and marked the area that needed to be cut out for the bungee cords.

Here's the airfoil in place. It's not ready for permanent mounting yet, but I had to see it on the airframe at least once!

And a quartering view.

More later

Monday, August 03, 2009

Shaping of the Langing Gear Airfoil

Started shaping the landing gear airfoil with a simple spoke shave and a lot of elbow grease. This little tool worked really well to get the basic airfoil cut to shape.

Then, I used the hand belt sander to shape to the proper contour, as checked by this cardboard template.

Then, my trusty twenty something year old Craftsman Belt Sander broke! Ah! A spring in the front roller assembly came apart thus endind the airfoil shaping for the day. I can't complain - the old machine never broke after those years of hard use, so I would say I got my money's worth out of the thing. Luckily, the support from Craftsman was good and I was able to get the parts from the Sears website. So Wednesday afternoon, I'll be back to making sawdust.

Several months ago, I was fortunate to correspond with John Morak. He was building a set of cabane struts for the restoration of a historic Curtiss Jenny in Fairbanks, AK and wanted to know if I had some drawings that they were missing. Once I saw John's work, I was impressed. I asked him to build a set for me and he agreed.

John took some spruce and bandsawed it to shape...

...and started carving.

A finished strut below.

Four finished struts with the Alaska wilderness outside.

Thanks, John. You saved me a lot of time!
I may have mentioned it before, but the EAA Chapter in Fairbanks, AK is restoring Ben Eilson's Curtiss Jenny for eventual display in the Fairbanks Airport terminal. Ben was a pioneed Alaska Aviator and his Jenny survived all these years, less the wings which were lost. The original OX-5 was replaced by a Hisso back in the late 1920's. I'm glad to see this historic machine being put back together.