Boeing Y1B-17 Project--1/48th Scale

[Second Air Force]

This change of the nacelles length -

I learned a valuable lesson on the engine nacelles. When I originally started planning to build this model many years ago I thought I had studied the dimensions quite thoroughly. I knew the fuselage was 18" shorter in front of the wing and that the back of the airplane was entirely different, but I thought the wing and nacelles were more-or-less the same as the later airplanes. Only after I started measuring a factory three-view drawing did I realize the differences in the nacelles. I am thankful that I didn't find this out after the wings were glued together or it would have been quite a problem. You can never have enough information on a conversion project!

Scott

[Letipapa]

I am very "fresh" modeler, and I haven't done any conversion (some "small surgery" - yes) still, but when I, in some future, come to that I'll remember your words.   :-wave

[No.1]

Scott- do you have blueprints or factory drawings of this nacelles? I can make precise technical drawings of this subject.

[Second Air Force]

No.1,

I have a pretty accurate three view drawing of the YB but no actual dimensions or blueprint. I overlayed the YB overhead drawing with a B-17G outline and determined the dimensions that way. If it will help I'll get you the material I have.

While I'm here, a couple of photos of the main landing gear. The Y1B-17 used pneumatic brakes rather than the later hydraulic type. On the Monogram kit there is a small container molded to the gear leg. This is a "debooster" and varies the hydraulic pressure being applied to the brake. I removed the deboosters in order to have room for the small fairings that the YB's had on their gear legs. The retraction jackscrew and motor/gearbox are made from aluminum tubing and some spare B-29 main gear door actuators from the spares box.

Boeing Y1B-17 Project--1/48th Scale

And a shot of the gear in the nacelle:

Boeing Y1B-17 Project--1/48th Scale

Scott

[No.1]

No problem about the drawings, most important that you have it arranged in scale for your work. What you doing on landing gear is amazing!

[samuraj77]

Amazing work mate....

[Letipapa]

That white inner structural grid, I suppose it didn't came with a kit, so you build it too, right? And, yes, whats that red tube inside?

Really amazing work
 

[Second Air Force]

Letipapa, I had to construct that support structure from plastic rod and sheet. The YB and 299 had these tubes in the nacelle to support the engines and the outer skin fastens to the cage. The thicker piece at the top of this photo is the trough that the exhaust system sits in on the original airplane. All later Forts had a fully monocoque nacelle and eliminated the need for this support basket.

Boeing Y1B-17 Project--1/48th Scale

That red piece is just a part of the plumbing that will be in the nacelle when it is complete. That is actually a piece of electrical wiring that happens to be the correct diameter for the tube I was replicating.

Scott

[Second Air Force]

I thought I would jump from the nacelles to the fuselage for a little update on that part of the model.

The forward fuselage of the "shark fin" Fortresses was 18" shorter than the E and later aircraft. The surgery was quite easy, just cutting the section out with the trusty razor saw. This photo is the first fit check of the shorter nose, using the propeller arc as an informal guide to the length I wanted. I used the prop arc and the aft rectangular window as reference points in order to confirm the dimensions were equivalent to the drawings I have.

Boeing Y1B-17 Project--1/48th Scale

Here is a bit of progress on the window configuration of the YB. The Koster kit actually provides a clear section to fill the cheek window but I decided to use plastic sheet instead. All the other windows, of course, are located differently than the B-17B and later.

Boeing Y1B-17 Project--1/48th Scale

Scott

[No.1]

Amazing surgery work and best at is that fuselage perfectly fit into shape

[Second Air Force]

The bombardier station has been a question mark since I first contemplated doing this conversion. I decided to simply get out the grinder and start removing plastic. The first photo is what's left after I removed the chin turret fairing from the forward fuselage.

Boeing Y1B-17 Project--1/48th Scale

The G fuselage really works pretty well to build the YB because the new bombardier sighting cutout goes exactly where the chin turret was.

This is the plug that I came up with. It still needs some adjusting before I glue it down, but you get the general idea of how it will look.

Boeing Y1B-17 Project--1/48th Scale

Figuring out how to get the correct window size and shape by adjusting the two side fairings was more of a challenge than I thought it would be.

Scott

[No.1]

You are right, works like this could be very hard... but it is very close to shape as I can see.

[Second Air Force]

Here is an early update on the forward fuselage interior. I first built up the cockpit floor and instrument panel front piece. This had to be finessed and shortened to adapt to the shorter forward fuselage and new bomb bay bulkhead. Then I started adding detail parts to the kit pieces, including the lower bulkhead enclosure and the floorboard that runs down the middle of the belly. The putty on the aft cockpit bulkhead will later be smoothed out and some details added:

Boeing Y1B-17 Project--1/48th Scale

Once that was all fitting as it should I moved on to the bombardier/gunner section. A floorboard was added for the gunner to stand on and the instrument panel/lower bulkhead were fitted to the fuselage halves:

Boeing Y1B-17 Project--1/48th Scale

Since it was decided a long time ago to open the forward entry door I had to add details to the lower fuselage area. I've spent enough time in this part of Chuckie to be able to build the floorbeams from memory. I hit my head on them enough last summer to leave a lasting impression. 

Boeing Y1B-17 Project--1/48th Scale

Here is a shot of the floor supports and right-side frames and stringers. I built the stringers this way so that I can slip them into the main fuselage in one piece. Once all the preliminary fitting and adjusting of the entire fuselage is complete I'll glue the three left and three right fuselage sections together at the joints. Then painting, detailing, and final assembly will go forward much like any kit, left and right halves.

Boeing Y1B-17 Project--1/48th Scale

Scott

[No.1]

This floor is something new- I was always wonder how the compartment inside look like, now I know Plastic strip work is excellent!

[Second Air Force]

All of these details are pretty rough at this point. I still have much to do to blend everything together. Interestingly most of these details will be unseen after the airplane is built, but at least we'll know the parts are in there! 

Scott