Fuselage

Sorry for the delay posting this blog. My Bucker Jungmann needed an annual inspection, and since it was already torn apart, I decided to finally installed that inverted oil system I always wanted. Things went pretty well, albeit it took longer than I anticipated.

Now, back to the Jenny!

Each splice gets two screws to help hold it together. I drilled and countersunk the hole and added the screws.



Then, I started building the top cross members. Each brace is a different length and has a different degree of taper. Watch out! The drawings show the dimensions at the centerline of the brace and does not take into account the taper.



I'll post more on this later. Each brace is also tapered laterally, too. I guess Curtiss was pretty weight conscious back then.



Here's how the universal fittings fit. Hope to have more in place soon.

enjoy

Brian

splices

The splices were glued and clamped today. I'll give them a good day or two to dry before finish sanding.



Also made a fitting drilling jig. I took a 2 in. C-clamp and removed the threaded part. From here, I inserted a tube to guide the drill bit. Lastly, I drilled a hole in the bottom side and inserted a 3/16 pin.



When the fitting is in place, I put the pin in the hole on one side, the guide in the hole on the other side and drill away. This ensures that your holes line up correctly. Hope you see this jig in action soon!

Enjoy

Brian

Rear longerons

Using the same routing jig, I cut the rear upper longerons and set them in place.



Here's a close up of the splice. Next step here is to run some brass screws into the splice, glue and clamp. Then, the whole assembly gets wrapped and varnished. The jig does a really good job of making the angles exact.



Here's another view looking aft. I have to cut out the tail post slot in the longerons yet.



Enjoy

Brian

Fuselage longerons

Very productive day today! After letting the steam-bent lower longeron bake in the sun for a day, I took off the clamps with good results. Here's the longeron in the jig.



For those of you curious, here's the amount of spring back after the clamps were released.



Now, the next step : There is an 11 inch splice that joins the front and back ash pieces to form the nearly 24 ft upper longeron. Thanks to Andrew King and Paul Dougherty, their advice made the process very easy. Here is how it is done.

First, the ash is rough cut on the table saw. I left about a 1/4 in. buffer between the blade and the cut line.



This jig was used to cut Paul Dougherty's Curtiss Jenny longerons and he graciously let me use it. Basically, it consists of two sides of plywood dadoed to make an angled floor to match the splice. This way, all eight eventual cuts would be identical. A router is used for the cutting as seen below.



Here's a finished cut. Very nice and precise. I practiced on a piece of scrap ash prior to cutting the actual longeron. I learned that the less wood the router has to cut, the easier the job. Also, I figured out the starting and stopping points and marked them on the jig.


Here's a finished cut.



Just for fun, I mated the finished longeron with the test piece (darker wood on left side). As you can see, it's a great fit!



Not only is there a splice, but the front longeron tapers from 1 1/2in. to 1 1/4 in. I used the table saw to rough cut again.



And sanded to the line with an oscillating spindle sander. This tool is a life saver!



After hand sanding, both upper longerons are now finished. More tomorrow.

Brian

Hisso Engine arrives

The Hispano-Suiza engine is now in Atlanta!

As part of the trip to Oshkosh (as mentioned on the previous post), we flew to Janesville, Wisconsin, rented a van and drove thirty minutes to a small town with an incredible array of antique airplanes known as Brodhead.

Here's a picture of our Hisso being hoisted aloft in Dennis Trone's shop....



... and into the van.




Success!



Snug in the van for the ride back to Atlanta.



Can't wait to hear it run. I better get busy on the airframe!

Brian

parts

Remember what I said about all those nice people out there......

Below is a picture of an original Jenny bellcrank assembly. I was searching for this part high and low for quite some time. I found out that fellow Curtiss Jenny enthusiast Bob Summers of Columbus Ohio had one in his collection and was willing to trade some other Jenny parts for it!

Once again, nice people came to my rescue.


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He also traded some 26 X 4 wheel spokes and a few miscellaneous fitttings. The bellcrank will be usable once I clean it up and put a new ball end in the middle for the control stick torque tube to attach.



I was fortunate enough the other day to travel to Oshkosh and see close up the Jenny they have displayed at the EAA Museum. This really answered a lot of my questions! The Curtiss drawings that survive have a lot of fuzzy areas. Seeing an uncovered Jenny really filled in the blanks. I came armed with paper, pencil, calipers and a ruler. The folks at the EAA could not have been any more cooperative. They let me look as long as I liked and even let me look closely at the Hisso in their Standard J1.

Speaking of the Hisso, we picked up our engine on the trip as well. More about that later.

Brian