Bell P-39 Airacobra "Cobra I" racer - Conversion of Academy 1/72nd kit

 

(The completed model can be found here:

https://wingsofintent.blogspot.com/2023/07/bell-p-39-airacobra-cobra-i-racer.html

Duplicating in a way the approach utilized to build the two Mustang "Beguine", using an Arma Hobby and an Academy kit, I built an Arma Hobby Airacobra "Cobra II" and an Academy "Cobra I" companion. Why? because in both cases the modifications needed to convert the military type kit to its civil racer counterparts involve a bit of surgery and modifications. This may provide some guidance for modelers that may go the way of the  latest wonderkit, or the common, much simpler and more affordable ones, that many modelers already have in their stash anyway. I am not saying that these kits are equal, they are not, the Arma kit is much newer and superior in many ways, but still a fair model can be built using a relatively old but good kit, so a wider range of modelers may feel tempted to do the conversions.

The Academy kit can be built partially OOB, plus of course all the deletions, additions and modifications needed, but I felt that a few things could be improved since there are a number of aftermarket accessories for it. I acquired CMK resin wheels that include the front LG leg, Quickboost new exhausts (the kit provides two types, but none match the racer ones), a Brengun photo-etched set, Eduard masks, and of course the Draw Decal set needed for the racer version, "Cobra I" as mentioned above (the red and black one, being Cobra II the yellow and black one).

This link will take you to the Arma kit build:

https://wingsofintent.blogspot.com/2023/06/bell-p-39q-airacobra-cobra-ii-racer.html

The racer requires among other many things a new propeller, so as with the Arma kit the spinner will be modified and four of the appropriate Quickboost prop blades installed.

Now regarding the photo-etched set, I will be only using a few parts of the fret, as I am not particularly comfortable around P.E. parts.

The Academy kit has nice external detail, a bit of cockpit detail and not very enticing wheels, hence the decision to enhance it a bit at a low cost. The kit doesn't provide masks, thus a set was as explained acquired. Being the canopy curved, I purchased a paper set of masks, opposite to vinyl ones, which invariably cause trouble for me unless the surface they rest on is flat. 

The various bumps on the kit's nose are deleted and the panel lines restored:

The chutes are filled with styrene bits:

None of the two exhausts is accurate for the racer, so an aftermarket set was ordered:

The button wheels are not thrilling as you can see below, so a set of those plus nose leg was also ordered:

The kit's L.G. doors are a bit think and not well detailed, so a P.E: set again was ordered:

The rib effect on the tail feathers of the Academy kit is better than the one molded on Arma kit rudder and elevators:

The P.E. set is for another kit brand, but I think will do (using just a few parts, by the way):

The chutes area is now puttied over:

Some preliminary airbrushing. Even the parts that I plan not to use are painted, just in case:

The cockpit is being prepared. A much simpler affair than the Arma kit needless to say, as to-date this kit is 30 years old according to Scalemates! The home-made underbelly fairing for the oil cooler is in progress:

The fuselage is assembled. You have to "trap" the nose landing gear linkage between the halves, not the smartest way to do it. The wing is added, a somewhat fair fit, but not perfect needing adjusting and putty. Detail is added to the back of the cockpit to hide the seam. The carb air intake trunk receives an extension used in the racer made with bent alu sheet (easier and speedier than carve one from solid styrene as I did with Cobra II, but a bit trickier to blend-in). The guns throughs are being puttied over. Antenna mast and Pitot locations have been plugged-in with stretched styrene:

Masks and correct exhaust for the racer have arrived:

The two Cobras:

The spinner has two of its three prop holes plugged. Three new holes will be made to accommodate the four-blades needed for the racer:

Prop ready:

Transparencies are on. Academy divided the canopy in two parts, front and back, glued to a central structural arch, plus one door, whilst Arma has a full canopy plus both doors separated:

Masks applied and first primer coat airbrushed:

The wheels and nose leg arrived. The wheels are nice, well molded, weighed, easily separated from their casting blocks, the nose ones presenting the two styles.

The CMK nose landing gear leg is one of the most impractical aftermarket parts I have ever seen. The part is made with that "special" very hard black resin, and the space between the "fork" legs at the end (where the wheel goes) is covered solid by a very thick web and a thick molding runner. The result: an almost impossible cleaning job as the surplus resin is, as said, very hard and brittle. What a bummer, and lack of thinking. 

Both Cobras are painted white as a base for their colors:

A bit of a contretemps. The airbrush decided to have a tantrum mid-session, and the tail area was affected with all kinds of splattery regalia. The paint in the area is removed once dry, the edges feathered, and hopefully another session will restore the finish:

The prop is painted white as a base for the yellow:

Main colors on both Cobra:

The props for both models are ready:

First set of masks off. Now the masking to paint the black control surfaces has to be applied:

The modification the racers have moving the Pitot to a long boom at the tip of spinner has to be replicated. First a rod of the right diameter is drilled:

Then the tip made conical sanding it, and then cut off. A metal NiSi tube is threaded through it:

A bit of a complicated masking to paint the control surfaces black:

Masks off:

In an apotheotic feat of intelligence, I forgot to apply the decals after painting, when the landing gear doors were still closed and it would have been simply a matter of applying them and cut around the doors, before removing the doors for final assembly. Brilliant falls short.

Now, with the landing gear deployed in place, I will have to measure and cut several individual subjects and pray that I get all aligned. Please, no applause:

The solution that came to mind was to scan the bottom view from the Academy instructions, and print it at the same size of the model, to use it as a pattern to cut the decals following the LG doors. Not ideal, but helpful. (Notice that the Draw Decals sheet does provide a couple of partial registration bits to help in case there is a problem):

The solution worked, and the bottom decals are already on. Now for the top:

The decals behave very well, allowing positioning and not tending to fold easily. Once they start to set they conform perfectly to the relief:

Both "Cobra" racers completed. Photos and a new post when I have good natural light outdoors:

(The completed model can be found here:

https://wingsofintent.blogspot.com/2023/07/bell-p-39-airacobra-cobra-i-racer.html