finally something other than wings!

The original (and the EAA replica) had steel airfoil shaped ribs, and an all welded constuction.

I would guess that they hydroformed the originals? and the EAA ribs were made over bucks.

As I do not currently have a 1000 ton press in my garage, I decided to go the alternate route and use a big hammer.
I began by having a set of 1/2 inch thick steel rib templates water jet cut.

But when they came back from the water jet cutter they were pretty crude, and while the basic profile was there, they needed alot of clean up, and the edges radiused.
This was my first experience with water jet cutting, so I am not sure if this was a fair example of the process, but I would be hesitant to use it again over laser cutting.
I had to make two form blocks for each rib profile to allow the 025 4130 material to be sandwiched in between.

I then made up a set of templates to cut the 4130 sheet blanks out.

Next I cut the blanks out, bolted them into their respective pairs of steel form blocks and proceeded to whack the ribs into shape. After having recently made so many aluminum ribs and formers for the ailerons, I forgot how much harder you have to hit steel. The ribs proved to be a good workout.

The various vertical and horizontal fin ribs are now formed, still to complete are the flanged lightening holes, but these are on hold as I have ordered a set of combination punch, and flanging dies, and they are enroute via dogsled or similar based on how long they are taking!
I have left the ribs slightly long to allow for an exact fit on assembly.
Once the holes are all punched an flared, I can build some basic assembly boards, bend the various 4130 tubes and start to fit the ribs.
I now have a set of very heavy steel rib form blocks, stored away gathering dust along with every other one off fixture no longer needed.
Maybe I should put up a photo of my fixture graveyard, although I find it rather painful to look at, so maybe not.