Revell Spitfire II kit design?

[RBrown]

While meandering the net I stumbled onto these Spitfire drawings. http://www.geocities.jp/yoyuso/spit1a/spit1ae.html

 

The drawings were created by Jumpei Temma , an exceptionally skilled modeler and artist.  What I found noteworthy was the how well they match the Revell 1/32 Spitfire II.  Just curious if these drawing had any role in the kit's design?

[Hans]

I don't know that, but he claims he used factory drawings to create his Seafire fr. 47 drawings. He probably did just that for this set.

Revell's kit is based on a 1:1 aircraft, if I remember correctly.

[Hans]

Out of curiosity I printed his Spit mk. 22 drawings. The rear fuselage measured from the rear of the exit door to the rudder hinge line is ca 5 mm longer in 1:24 scale on his drawing than the same aera, measured on the Airfix 1:24 mk v Spitty and the Peter Cooke mk xiv drawings, both of which have the same lenght. Did the mk. 22 have a longer rear fuselage, is the drawing incorrect, or is it due to cropping and stretching by the printing software?

Edited September 22, 2015 by Hans

[D.B. Andrus]

Thanks for posting, Rob. They're beautifully drawn.

 

Cheers,

 

D,B,

[RBrown]

Out of curiosity I printed his Spit mk. 22 drawings. The rear fuselage measured from the rear of the exit door to the rudder hinge line is ca 5 mm longer in 1:24 scale on his drawing than the same aera, measured on the Airfix 1:24 mk v Spitty and the Peter Cooke mk xiv drawings, both of which have the same lenght. Did the mk. 22 have a longer rear fuselage, is the drawing incorrect, or is it due to cropping and stretching by the printing software?

 

The length of all Spitfires from the firewall (Frame 5) to the rudder hinge was the same, 245 inches or 6223 mm.  In 1/24 scale that is roughly 10.2 inches or 259.3 mm.

 

Now from the rear of the exit door to the rudder hinge line the figure is 171 inches or 4343 mm. That works out to 7 1/8 inches or 181 mm in 1/24 scale.

 

This is data that I have collected from multiple sources and is based on measurement of actual airframes.  I am not an expert on Spitfires, just an enthusiast, but I am confident in the figures.  The drawing below is presented for purpose of clarification and shows the fuselage from Frame 5 to the rudder post.

 

Edit: The measurement is made at the datum line indicated in the drawing.

 

Edited September 23, 2015 by RBrown

[Chek]

OK thanks for the data, but. one problem is that the rudder post is not vertical,

 

So is the measurement from an imaginary vertical line plumb from:

a ) the top of the post, or

b ) from the top corner of the hinge cut-out, or

c ) from the bottom corner or

d ) where the forward leaning lower post meets the horizontal datum line?

 

Without knowing what exactly is being measured, millimetre precision is of limited value.

 

Edited to fix 'b' plus ')' producing that > 

Edited September 23, 2015 by Chek

[LSP_Ron]

Actually the rudder post is vertical with a kick out at the bottom, you need to measure at the horizontal datum line shown at the left and right side of the drawing.

 

datum line ‎(plural datum lines)

1. (engineering) A line which serves as a reference or base for the measurement of other quantities.

[Hans]

Rob & Ron, thank you for the clarification.

 

Hans

[Chek]

Ron, it may be that the rudder post should be vertical, but in the frame drawing above it isn't.

It inclines rearward by a few degrees.

My graphic program can't calculate the exact angle on screen, but does tell me it's not a vertical line, which is why I asked for clarification.

 

[mattlow]

Is this because the drawing is showing frames, not the skin (which is what we see of course). The horizontal structure above the datum appears to extend to meet the 'vertical line'.

 

Matt

[Edgar Brooks]

Is this because the drawing is showing frames, not the skin (which is what we see of course).

No, it's because of the use of the datum line, not the thrust line, which was/is angled up about two degrees. Run that back to the tail, and the rudder post is at right angles.

There are one or two other points (can't comment much on the drawings, since they're too indistinct on my computer):-

Leaving the irritating "19th. Squadron" (which never existed) I should point out that the central panel line, on the fuselage, is not straight, but has a pronounced downward "kink" just below the radio hatch (both sides, in fact.)

No RAF wartime aircraft ever had a glossy finish.

"Mixed Grey" as a title, never existed; 11-8-41 the Air Ministry asked RAE Farnborough to provide colour samples, plus a name, for a new colour which could be produced from a 7:1 mix of Sea Grey Medium:black (easily done by removing 1 pint from a gallon of grey and replacing it with black.) 21-8-41 (only 10 days later) the name Ocean Grey was issued.

[Chek]

Well, Edgar is bang on regarding the 2 degree thrust offset bringing the rudder post into true perpendicular.

So all that remains is verifying that the measurements previously quoted are taken in the same plane (ho ho - no pun intended).

 

Whilst all this may seem academic to the 'looks like a Spitfire to me' contingent, to those who chop kits up in attempting to produce accurate models, it isn't.

Edited September 23, 2015 by Chek

[RBrown]

Perhaps some have misunderstood the purpose of my posting and the drawing.  Hans posted a question about a discrepancy between the Airfix kit and two sets of plans regarding the length of a Spitfire XXII  from the rear entry door to the rudder post.

 

I posted measurement for this, as well as the length from Frame 5 to the rudder hinge line.  The drawing was posted only to show the datum line along which the measurement was taken.

 

The drawing should not be considered a scale plan. 

 

In short  all Spitfires were the same length from Frame 5 to the center line of the rudder hinge, and this length was 245 inches along the datum line.

[Chek]

But that is precisely the point, RB.

Is the "rudder hinge line" as per your first drawing posted,with the horizontal datum, and undetermined position of the rudder post, or is it as per my adjusted drawing with Edgar's 2º thrust offset?

The two dimensions can't be the same.

[RBrown]

Chek, perhaps this will help...

 

Here is a portion of a Supermarine engineering drawing illustrating the intersection of the datum line and the C/L of the rudder hinge line.  Although not noted on the drawing, the intersection is 0.7 inches beyond the edge of the vertical fin.  All drawing measurement are in inches.

 

Again the drawing is for orientation purposes only,  it is the measurements that are pertinent.   Apologies in advance for the poor quality of the image.

 

Edited September 24, 2015 by RBrown