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

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a certain dictator once described Willy Messerschmitt as having the skull of a genius. He clearly hadn't met you at that point!

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Hi folks :)

 

been a while - it's got to a really tough bit of the build...

 

On 8/5/2019 at 6:58 AM, KevinCG said:

G'day Peter,

Your work is superb. Congratulations

 

With respect to your your seat belts I feel a word of caution maybe required as I have noted that there can be problems over the longer term using lead where it comes into contact with some other metals due to presumably differences in galavanic index.  The lead or other metal simply disintegrates over time, the metal with the lower index  (ie more -ve) dissolves or goes to powder.  This happened to me many years ago on a 1/24 scale Me 109, where the belts just disintegrated after 10 or so years.  I have subsequently eschewed lead. I have seen similar issues with white metal on older models in museums etc.

This may not be an issue in your case as I do not know what from what metal you have etched  your  buckles and clasps but it maybe worth checking. Any difference greater than 0.25mV is likely to cause an issue.

According to Wikepedia Lead has an index of -0.70, brass  -0.4, Copper 0.35 and nickel -0.3. It gets a bit more complicated when alloys are involved.

I hope this doesn't apply but it's worth knowing for the future.

Cheers

Kevin

 

 

that is really interesting & a bit worrying Kevin :unsure:... I guess I will just have to see what happens - the etch is nickel silver so i guess they may react one day - fingers crossed I get lucky :)

 

so, what's been happening...

 

I got the cockpit pod assembled in a jig and got it in the airframe...

 

WIP885_zpswkt9fh6t.jpg

 

WIP886_zpsplmxvvwq.jpg

 

..the external sidewalls of the fuselage have also been added & faired in..

 

..I wanted to get the rear window area sorted so I started by making a plug for vacforming but once I had a go with my usual dismal success at vacforming PETG (I get distortion etc) I realised the curves are not compound really so I just bent some sheet in boing water and made a slit along the top rear edge so I could pinch it in a bit to get the upper profile..

 

..the windows were then set out and the covering removed - I had an etched template I did that matches the framing I also had done as these are really difficult to do freehand..

 

..also made the inner skins and the front former which were painted black on the outside & green on the inside..

 

WIP887_zpsx7ehlyly.jpg

 

..then added to the interior (carefully!) - the seam doesn't matter as it will be covered, and the little metal brace at the back is so far down the fuselage it cannot be seen..

 

WIP888_zpspjgjbfn8.jpg

 

..there are some gubbins on the roof of this area so these were made up in metal & plastic and wired up..

 

WIP890_zpsyw3ba2vs.jpg

 

WIP889_zpscbztvqhs.jpg

 

..then as I was about to add the assembly and fair it all in, I thought I had better get the front windshield fuselage area done as if there is any sanding, all the dust will get in the rear cockpit and I will never get it out..

 

..I had drawings - you can see the windshield drops down each side of the upper curve of the fuselage and actually the armoured glass panel goes right through this area..

 

WIP898_zps4qv0opnn.jpg

 

..I made up templates as there is so much three dimensional geometry going on it is really (and I mean really) difficult to fabricate..

 

..one shows where the IP coaming is in relation to the windsheild, the long one is just the overall upper profile with a vertical where the rear of the front windshield is..

 

WIP893_zpsdkwlvxai.jpg

 

..I made up many more templates and plugs for moulding the windshield & coaming - I also spent days trying to figure out why things were not lining up before I realised the top of the fuselage was very lop-sided so the half-round template is to correct that..

 

WIP891_zpstafyvyqi.jpg

 

..one of the coaming vacforms - this is wrong but each tester gets me closer... one thing I am struggling with is on many cockpit pics the panel does not look set back very far, but every factory drawing has it set quite deep - it has to be deep as that is where the panel goes in the cockpit pod, but it is a bit of optical trickery I am struggling with..

 

WIP892_zpscxvsmltl.jpg

 

..so some overall shots of the mock-up windshield and the rear glazed area - once I get the plug for the windshield I will probably just plunge mould PETG panels in boiling water as this completely preserves the optical clarity and assemble individual panels to make it up..

 

lots and lots of fettling & thinking to be done in this bit...

 

WIP894_zpssa02n7ld.jpg

 

WIP896_zps3vzs0mpf.jpg

 

WIP897_zpsyhp7up5w.jpg

 

WIP895_zpsko4kucwt.jpg

 

..back when I have some meaningful progress :)

 

TTFN
Peter

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14 hours ago, airscale said:

    I will probably just plunge mould PETG panels in boiling water as this completely preserves the optical clarity

 

Interesting ... thanks Peter.

 

 

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Well done Peter,

 

I can absolutely understand the complexity of what you're trying to do here. Having all the drawings in the world doesn't make producing a 3 dimensional part any easier!

 

That little metal box with the wires coming out of it....... how did you make that without seams? Advanced trickery and awesomeness I take it? ;)

 

Brilliant work as always though.

 

Craig

 

Oh yes I got up close and personal with the real deal at Oshkosh. Took plenty of pics for you, but I think you have the situation well and truely in hand!

 

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Fnah, you missed the little paper label hanging from the string on the silver box thingy. 

 

I look at the photos of the real thing and then look at the parts you make. I think "hmmm, that doesn't look quite right" and I refer back to the photo. Then I realise I missed some little detail that you have added. You must have eyes like an eagle and the patience of a saint.

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Nice problem-solving and execution.  Good work on the windshield master, a complicated shape, and pull.  Good luck with the hatch.

 

Sincerely,

Mark

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The windshield looks to be a major challenge.  It was a shortcoming of sorts on my 1/18 P-51D which has an entirely different windshield.  And I overcame it by completely scratch building the wind shield.  It was entirely single curvature (or nearly so) - which allowed me to simply roll form the "glass" from thin gage clear plastic, as opposed to a vac form.  The periphery trim being the biggest challenge - to mate it to the existing shape on the fuselage, and  the posts and frame.  

 

Also, I took that opportunity to make the posts and aft frame in such a way that they would accept the "glass", and look like the separate parts that they truly are.  This also allowed me to use thick gage clear plastic for the bullet-proof flat screen.  

 

With the exception of the small upper compound-curved segment (which would require a vac form), you could do the same thing if you wanted.  Oh what a project it would be - but with your mad skills anything is possible!  However I have no doubt you will make it look totally real no  matter what method you choose.

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