Taking the Plunge: Kitty Hawk P-39 Airacobra WIP

[petrov27]

Those cuts look just the ticket! Seems like a aftermarket company could market a extension plug in resin for this kit

[LSP_Kevin]

Good show. I was thinking that a diagonal cut would do the trick, but your method does seem to work well.

 

Keep it coming

 

Hubert

 

It also provides more strength than any kind of single cut would.

 

Kev

[David Hansen]

Nice job. The extension of the rear really improved the proportionality of the whole fuselage. And i'm not even a big fan of the P-39!

 

david

Edited March 5, 2016 by David Hansen

[Chris McMillin]

Love it. Super model build, very nice fuselage extension.

I liked the airplane as a fighter in stories about how they were operated in Russia. The Russians added strengthening aft fuselage doublers and removed the wing mounted .30's for reduced weight and increased roll rate and rerigged the cannon and nose .50 charging cables making the airplane combat ready. The 25 to 50 kill Russian aces in the type is impressive to me. Too bad the Army was so behind and stiff about such mods, but Buzz Wagner's 2 kills in the P-39D is a very good account.

The modified P-39Q Cobra II that won the Thompson Trophy pylon race in 1946 qualified at a two lap (60 mile) average of 408 mph and finished the 300 mile final race at 373 mph, so it was obviously a good airplane aerodynamically and excelled at this 800 foot elevation airport/race course.

Chris...

[quang]

Thank you all for your comments. I always thought of the P-39 as a pudgy little fellow, well it's NOT.

 

Other than extending the fuselage, my biggest concern is to restore the compound curves with a minimum of puttying and sanding. I think that the staggered cut method is one way to do it.

 

I dry-fit the the fuselage halves together with the internal chassis. Everything fits perfectly as per the book. And most important, the fuselage is not distorted, the vertical tail is straight and true.

 

So far so good.

 

 

 

 

 

 

 

[quang]

With the clear parts on. Again, a very good fit. 

 

 

 

[madcop]

Hi Quang

 

This really reminds me of long modelling session back in the 80ties...full of discussion, calipers, glue, milliput, arguments , Arthur Bentley, Turpentine, Schmetsov, coupole, coffee and cigarettes and women forbidden .......

 

Real good old modelling technique. I really hope that after having done this rear fuselage correction you won't skip the nose little mishap. I really like that beast....

 

Go on like this it still inspiring me after all these years.

 

Congrats.

 

Madcop.

[David Hansen]

It'll look awesome once the sanding sticks come into play. Muwahahahaha!!

It's a little hard to tell from the photos, but it looks like the splice gives you a smooth, unbroken contour along the belly. Is there much of a "step" along the spine where the two halves are stretched?

 

-d-

Edited March 6, 2016 by David Hansen

[David Hansen]

As they say, there is more than one way to skin a cat.

Yes, but somebody has to go first. You did.

 

-d-

[David Hansen]

And now the GOOD news:

 

The front and aft parts of the fuselage line up 'perfectly' with the photo. The shape of the rudder is off and the nose is 2 mm short but these are small meat compared with the overall length issue.

 

 

A picture is worth a thousand words, and one test is worth a thousand expert opinions.

-d-

[quang]

 

This really reminds me of long modelling session back in the 80ties...full of discussion, calipers, glue, milliput, arguments , Arthur Bentley, Turpentine, Schmetsov, coupole, coffee and cigarettes and women forbidden .......

 

 

 

Aah! Don't tell me, old school modelling!

[quang]

It'll look awesome once the sanding sticks come into play. Muwahahahaha!!

It's a little hard to tell from the photos, but it looks like the splice gives you a smooth, unbroken contour along the belly. Is there much of a "step" along the sine where the two halves are stretched?

 

-d-

There's a small step indeed to be dealt with, but nothing horrific as you can see;

 

Before sanding

 

A thin coat of acrylic paint is applied to the plug area.

 

First rough sanding with half-round files.

 

Thin layer of Milliput added;

 

Fine sanding with Micromesh followed with thin coat of acrylic primer.

[quang]

The sanded area is kept small to preserve a maximum of detail.

 

 

Behind the scene. Apart from some epoxy putty used to reinforce the plug, the original plastic is left untouched.

[madcop]

Hi Quang

 

 

Wouldn't it be easier and more convenient to add the x mms in front of the windscreen so as to keep the upper and lower cowling profile. Putting the plug behind the propeller backplate looks like the upper curve of the cowling is going to be accentuated. I do not think that the nose leg should be a problem. (I do not have the model, some late visitor took the box with him ! ) 

 

Just my 2 cents.

 

Madcop.

[stevegallacci]

The rear fuselage stretch is need there for that is where the shortfall is. The proportional location of the radio hatch needs it, even more so for the SH kit. It was the nearly square hatch that didn't seem to locate quite right on that kit versus the hatch on photos that helped tip me off to the dimensional bug with the various P-39s to start with.