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

[DonH]

He just keeps going, one superb piece after another.

 

Looking forward to the bumper UK Bank Holiday edition of this build thread 

[dodgem37]

Very cool.

 

Sincerely,

Mark

[Out2gtcha]

WOW!  Im more and more blown away each time I visit one of your threads Peter..................as the others have said, no more superlatives left! 

[airscale]

thanks folks

 

a little more done..

 

I started to shape the rollover casting at the top of the 'A' frame behind the seat - just a chunk of brass shaped to a PE template I got from the drawing..

 

 

..and once it was finished it was added in place..

 

 

..also added some of the bigger bolts to the assembly - a few more to go..

 

 

..I used some 3.2mm 'U' shaped brass channel to form the fuselage longerons - the PE structures have been designed to fit into the channel. These were again bent from the scaled drawing with the kink in the lower one being done by slitting it. bending it, and soldering it back up..

 

 

..once I had the longerons made, I had to start thinking about a jig so I can assemble the sides - I used the drawings I made doing the PE and derived enough to set out some templates forwhere the longerons sit at front & rear. I also marked where the major fuselage stations are and will work this up into a proper jig..

 

it's just resting together for now..

 

 

 

 

..I think I need to do the sides as units so I can remove them and detail them otherwise it would be tricky to just work the whole coskpit up from this assembled state - I would be forever trying to reach inside & wll likely get frustrated

 

..it should serve useful to get everything lined up though..

 

TTFN

 

Peter

[Out2gtcha]

Wowzzers!

[LSP_Ray]

I was thinking more like, 'Holy Crap!'

But I think I used that line in the Spit build, too.

[rtwpsom2]

Peter, the longerons are not U shaped, they are H shaped, this is very apparent on the upper longerons in an open cockpit, but not as much on the lower ones.

 

Upper left hand longeron 102-31120 viewed from ahead and slightly inside the fuselage:

 

view from outside frame:

 

Lower longeron 102-31121 from inside the frame:

 

 

From outside the frame:

 

 

cockpit wall sub assembly 102-31107 inside view from above:

 

 

from below:

 

 

Here you can see how obvious it is, there are no covers or special pieces to clean up the lines, the channel along the cockpit edge is the actual longeron:

 

 

Something I would add in this case is to make sure and look at the BOM for the part, it will tell you what material to make the part from.  This may be obvious in the case of  .064 aluminum sheet and similar, but in this case it gives the material C194-A. This generally means it's an extruded channel.  For those there are two sources of info available to you for ommon channels used by NAA.  The first is the P-51 Structural Repair Manual, starting on page 440 it lists dozens of extrusion shapes and their specific dimensions. Looking through there we find no C194-A channels listed, however on 445 there are two channels that looks suspiciously close to the ones for the upper and lower longerons labelled 3E8T and 3E13A, keep those in mind.  Those numbers denote NAA common component drawing numbers.  The NAA Standard Drawings that apply to P-51 also happen to be indexed on Aircorps Library.  Searching for 3E8 get's me this page, which if you read the notes at the bottom carefully, you will find specifically says that 3E8 was formerly called C194. I am sure if you put in 3E13 you'd find the same channel that was used in the lower longeron drawing.

 

 

 

 

 

 

Edited August 28, 2018 by rtwpsom2

[Trak-Tor]

Keep it up, guys. 

This is some excellent reading for the morning.

The shape of the longerons may look like a problem in Houston, but I'm sure Peter will overcome this with his magic wand in no time.

 

Juraj

[dodgem37]

You can also run the slot to the edge, slide one side out, roll the jig onto its'side, and work on one side at a time.  Just sayin'.

 

Nicely done, Peter.  Great details.

 

rtwpsom2, great knowledge base.  It's always enjoyable making minute discoveries such as you've conveyed.

 

Sincerely,

Mark

[airscale]

4 hours ago, rtwpsom2 said:

Peter, the longerons are not U shaped, they are H shaped, this is very apparent on the upper longerons in an open cockpit, but not as much on the lower ones.

 

Here you can see how obvious it is, there are no covers or special pieces to clean up the lines, the channel along the cockpit edge is the actual longeron:

 

 

 

 

 

Oh my - rtwpsom2, you just demonstrated the power of having a wingman on a build like this

 

for some reason I thought the top of the 'H' was covered at the cockpit sill, but I can see now that it is not. I had also wondered how it tapers and is open where it loses one side of the 'H' after the seat area so your CAD is super helpful in setting this out in a way a drawing is not so obvious

 

The good news it is an easy fix - I just ordered some 3mm H section so will make them up again - I will leave the bottoms as they are less obvious and that is the section / dimension all the station parts will fit into

 

Marvelous - that could have been a major schoolboy error!

 

Thanks again

 

Peter

[Out2gtcha]

Great stuff gents.  rtwpsom2, that's exactly the kind of stuff we love seeing on LSP!  SMEs are hard to find, and when one comes along with previously unknown info, its always super helpful, and I think we can all appreciate the effort it takes to deep dive on this kind of stuff.

[MikeA]

I was blown away by the Spitfire build. Not really sure what words to use for the amazingly detailed and superbly executed work going into this one. As to where you get the time to do this stuff is completely beyond me. But what I really like is how much of it doesn’t involve super expensive tools or hard to find material. Much of it is patient exacting work taken to another level again - stratospheric at least!

 

Amazing and and very very inspirational. 

 

Cheers

 

Mike

[Hacker]

[airscale]

Hi folks,

 

Longerons reworked - big shout out to Eileens Emporium for getting me the H section brass for the longerons in less than 24hrs from ordering - they came next day so I have had a chance to rework them according to the drawings

 

I also made up the jig that allows me to add the station points and skin the sidewalls

 

..the main seat bulkhead & the two behind are not glued - just the stations on the sidewalls, but here is where it is at so far...

 

 

 

 

 

 

 

now onto the skinning..

 

TTFN

Peter

 

 

[Trak-Tor]

I've told you. It's magic.

 

Juraj