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1/18 P51C Mustang "Lopes Hope the 3rd"

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Posted (edited)

evening folks & thanks for stopping by :)

 

On 1/7/2019 at 3:19 AM, JayW said:

The drawing that defines the distinctive lower intake fairing is 102-310119.  On that drawing you will see that the fillet that takes up the space between this fairing and the fuselage is far from v-shaped.  There is a pretty crazy looking discontinuity in it which is for, if I am not mistaken, cockpit air venting.  My memory might not be right.  But if you want to tackle that odd shape, pull that drawing.  Good Luck (I didn't do it on Miss Velma).

 

Yep, thanks Jay, I spotted that on the drawing, it was just easier to start with a rough shape and get rid of the form to capture the intake - please keep your notes coming though as I easily miss things!

 

23 hours ago, KUROK said:

Yes, that lower intake on B/C/D mustangs is offset from the lower wing surface due to boundary layer interactions (I'm an AERO eng).

That weird thing on the drawing is in fact a fresh air intake and I think it might be cockpit fresh air?

 

I think it might be - it's certainly directing airflow somewhere:)

 

so, more mustang mayhem...

 

..after shaping the basic filler construction of the airscoop, next was cutting out the air intake on the roof - I made a template from the drawing..

 

WIP497_zpstj7jkzmn.jpg

 

..then with filler & dremal work I got the rounded sections done..

 

WIP498_zpsbgxo4p0d.jpg

 

..after this I had toreskin the inside as the skins I put in earlier had a join line down the middle and the real one doesn't. To dothis I lined the interior with tape and drew out the boundaries to when I remove the tape I can unravel it and get a template for one piece of rivetted litho to dress the inside in one go..

 

WIP499_zpsmgaletwk.jpg

 

..next I wanted to get the positioning right so I can partly skin the scoop in aluminium and fit it so I can add all the fuselage skinning later on.. This took the entire morning to get right as it is such a critical feature of the airframe (not helped by the plans I was using having it in the wrong position too far back...)

 

I put tape on the mating faces and added tiny drops of CA to hold it in position so I could add the filler - this process was then reversed to I make the part match the fuselage - the net result is the parts fit together seamlessly...

 

WIP500_zpsqkyzsqgb.jpg

 

..it was also braced inside before I started so the filler didn't collapse under load...

 

WIP502_zpsy67scl97.jpg

 

..then the fist bit of ali skinning on this model - coincidentally the first on my Spitfire was also an air intake..

 

..hard to see whats going on here, but on the right hand side is a sheet of soft ali under some masking tape - it is being held, rubbed,, stroked and tapped with a tiny hammer to start to conform to the shape of the roof. the black tape borders can also be seen at the nose - these leave an imprint in the ali so I know where the borders are. Its a  tricky shape as not only the shape of the scoop, but also the flaring at the top where it fairs into the fuselage...

 

WIP501_zpszjxlku4s.jpg

 

..I end up with a useable part that has adopted the shaping well.. this was added with contact adhesive...

 

WIP503_zps8eniicjx.jpg

 

..then the other side - this time with the added complication of the intake aperture..

 

WIP504_zpsntuqdtky.jpg

 

..it proved impossible to do the little intake in one piece so I added another in the inlet,,, then after cementing all the tape is removed and we have the base layer of ali down... you can see it's quite rough and creased in places, but this all sands out...

 

WIP505_zpsqhxlamet.jpg

 

after sanding aout all the defects the first sking is done & just needs finessing & rivet details but I will leave that until later

 

WIP510_zpsfu5cqmju.jpg

 

WIP511_zpsgbfqt7an.jpg

 

WIP509_zpssjdwym6h.jpg

 

 

..the intentionj is to get all i can done while I have access (so a bit of the wing surface where this sits needs to be done too) and then fix the scoop in place,, the nose intake is next and that is going to be a real challenge :)

 

TTFN

Peter

 

 

 

 

 

 

Edited by airscale

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Excellent. When I see what you can achive with sculpting and the litho I just wonder why you don't scratch the entire plane. Making the fuselage would almost be a walk in the park for you. 

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One more thing Peter - there is a vertically oriented blade of sorts that is situated right on the centerline of the scoop, and right on the nose of the transition fairing you have so skillfully created.  Most know of this feature, but most do not know that it pierces upper skin of the scoop and continues right up into the fuselage.  Provide for it on your scoop.  Drawing number for the blade is 102-31080, and its installation shows up on wing install drawing 102-10001 (see zone A8). 

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evening ladies :)

 

5 hours ago, JayW said:

One more thing Peter - there is a vertically oriented blade of sorts that is situated right on the centerline of the scoop, and right on the nose of the transition fairing you have so skillfully created.  Most know of this feature, but most do not know that it pierces upper skin of the scoop and continues right up into the fuselage.  Provide for it on your scoop.  Drawing number for the blade is 102-31080, and its installation shows up on wing install drawing 102-10001 (see zone A8). 

 

 

..exactly why i need you on the team Jay - I saw the little blade in the intake, but had not seen it actually goes right through to the fuselage - what a wierd little structure...

 

..thanks for pointing it out - will be a devil to fit but will give it a go..

 

so I have skinned the front fairing of the intake..

 

first the inner liner was added and rough cut to the edge, this was later sanded & filed flush with the intake lip..

 

WIP512_zpsaytlkbrf.jpg

 

..then the outer skin, I thought the best way was to try and wrap it as near as possible and try to get the join out of sight at the bottom...

 

WIP513_zpswp5ndchw.jpg

 

..the skin had one good straight edge along the panel line of the first part so this was the reference point from where everything else must follow - this was taped down so as not to move in the beating process..

 

WIP514_zpsbiick6h4.jpg

 

..at this point the ali is coaxed to follow the compound curves with a mini ball pein hammer - this is a long process of tapping all the creases into flats...

 

WIP515_zpsndnsgh4s.jpg

 

..ultimately the metal gives way and the shape is good enough to stick down. I use contact adhesive and in this case was lucky I could unfurl the metal so as to hinge via the adhesive tape along that top panel line - that way it just folds back perfectly into position. Then more tapping and cutting and the result is a rough leading edge, but good enough to work with...

 

WIP516_zps8fyuk9c7.jpg

 

WIP517_zpsxok8xoze.jpg

 

..this is then rough sanded & filed to get near to a finished surface... the photos show where I still need a few tweaks, and will try and add a sliver at the join line, but overall a tricky part is done..

 

WIP518_zpse9mw7w70.jpg

 

WIP519_zps2l8pdcfc.jpg

 

WIP520_zpsyyb6fk8e.jpg

 

WIP521_zpsxdraryb1.jpg

 

WIP522_zpsj8vmzknn.jpg

 

..until next time..

 

TTFN
Peter

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The radiator / oil cooler scoop is a signature feature of the Merlin P-51.  You have to get it right.  You have represented it in great fashion.   

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Hi

Following this thread is like following a TV series. There remains one hoping that it will happen in the next chapter ....

Beer and popcorn, to wait for what follows of the show..
Greetings from Colombia

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