B-21 Bomber "Mini-Fortress"

[John Howling Mouse]

I know, likely not an original idea.  And I realize the designation is probably wrong, too.  Anyhow, this old (1962) 1:72 Airfix Flying Fortress kit is good for only one thing: cuttin' up! 

This will be a shortened, twin-engined B-17 to compete with that pesky B-25 Mitchell.  I plan on re-writing the Doolittle Raid with these instead.  So, picture a Mini-Fortress but with a whole lotta features removed.  I'd sure like to have it sitting on tricycle landing gear like the Mitchell but I don't know if that's possible with the dimensions involved.

Wing cuts were easy:



Here's where the dilemma lies: shortening along a taper.  There's a special way to do a zig-zag cut but that's easier said than done.  As Princess Leia said: "Help me, Obi-Kitnut617, you're my only hope!"

[cthulhu77]

Sir John, this looks to be another amazing buildup.  Love it!

[noxioux]

Mini Fortress or Maxi-Marauder, that is the question. . .

That transition on the tail will be challenging.  I think I would cut away the original plastic, use some sheet styrene underneath for a 'foundation' and putty away.  Do you have a plan of attack?

[John Howling Mouse]

Do you have a plan of attack?

Yep, the plan would have been to send it to Kitnut617 and let HIM figure it out!  I've already hacked it to bits, removed the section in the hopes that 1:72 scale would lend me enough fudge-factor----it doesn't, by the way.   

Actually, in hind-sight, the Airfix kit was probably the worst choice as it's a poorly executed/engineered kit to begin with, molded in brittle plastic, is segmented to allow "moveable flying surfaces," and the starfields of raised rivet details make replacement sections and putty/sanded areas nearly impossible to blend in.  I should have used my Matchbox kit but it's just sooooooo nice.

You'll see I have Thor's Hammer at the ready in case this little challenge fails to pan out:

[Wyrmshadow]

Very interesting. Reminds me of the Tupolev SB-2 Katuishka

[Captain Canada]

That's an awesome 'little' idea, baz ! So glad you're back in the saddle and running at full gallop !

[kitnut617]

Email sent Barry,  if you plan on making this into a tricycle u/c I would slide the wing back so the trailing edge lines up with the rear root fairing and modify the front of the root fairing.

[The Rat]

YIKES! You do like to put yourself through it, don't you? I once knew a chick who was into whips, chains, Jello and naked skydiving, you're making her look like a puritan.

And no, I don't have her number.

[jcf]

You could say it is a development of this:

Boeing Model 298

The XB-21 Dragon was built by North American Aircraft.


The XB-22 designation was originally used for a Douglas proposal for an R-2600 engined B-18, the project was canceled in favor of newer aircraft and the designation dropped. It was never reassigned...

until now. 

Jon

[gooberliberation]

Gonna keep waistguns or are they gone for good?

[K5054NZ]

I was gonna refrain from comment and await further build pics, but the pic of her taped together made me realise how cool this baby is going to look! I need to find a small scale B-17 and do a tribute build!

Making her a trike would, I believe, top it off nicely. Mind you, the idea of using Allisons does sound very appealing....

[Orne M]

John,

Did similar alterations with my AB-38, since it was tricycle landing gear (retracted, but the doors are there).  Remove whatever fuselage-plug is necessary to shorten the wing-root to match your new wing-chord, and add another fuselage plug forward of the wing-root between the leading-edge and the cockpit windows.

[ysi_maniac]

 
This guy is really good

[The Rat]

Okay, so howzabout dis; the openings at the join are left there, with waist guns in them!

EDIT: I meant to say that they would have an excellent arc of fire to the rear (you might even be able to dispense with the tail gun), and the outward curve would perhaps improve the aerodynamics somewhat. IIRC the waist guns had a bit of a wind deflector in front of them for that purpose.

[John Howling Mouse]

Thanks guys.  Two of the best things about the people on this site are the encouragement and the sheer knowledge you folks possess. 

Kitnut617 sent me some fantastic "how-to" advice which I'm hoping he won't mind me sharing here on the forum.  In fact, his pics and text should be turned into a full-blown article (I'd be happy to submit this on his behalf as long as he's okay with it).  His method is really the only way this will stand a chance of success, so I think it's time I pull out that great little Matchbox kit and use it instead of the Airfix one I've already butchered (incorrectly).

Here's his explanation:

Keep in mind I don't have a Fortress in front of me so I can't see what the fuselage looks like in the plan (top) view,  so from memory I think the fuselage between the two lines you have drawn is not as tapered as in the profile (side) view.  You may need to modify what I'm going to suggest to best suit this,  but I would maybe cut the fuselage at your left line (cut #1) first.  Cut #2 would be a 'Z' cut (try to keep the widest point of the fuselage as far forward as possible)  Cut #3 would go horizontal for the same distance as the horizontal part in cut #2 first, then vertically to the crease line of the turtle deck and then along the crease line of the turtle deck.  This would be so you can slide the rear fuselage under it when you come to re-join the two halves.   You'll notice I've drawn in some triangles, this is so you can swedge down the fuselage to match the smaller rear fuselage, but do this in small amounts at a time, starting with just the width of your saw blade and then gradually making the triangle mouths wider until it can be massaged into shape.  Note: the horizontal cut should be on the widest point of the fuselage when looking in the plan view.  The turtle deck is the fairing from the front windshield back along the top of the fuselage.



BUT BEFORE YOU START, KEEP IN MIND OF THIS:

You'll have to have a good look at the fuselage from both directions (plan & profile) to really determine where Cut #1 has to start and actually look like.  It may have to be a smaller 'Z' cut, say starting vertically down just at the end of the turtle deck to my horizontal line then proceeding along horizontally until you get to your rear most line (on the right near the large window) and then cut the rest of the 1st (left) vertical line where you show it.  What you are looking for is somewhere on the fuselage when looking in the plan view, where the fuselage is almost the same diameter.