Kawasaki Ki 61 Hien (1 Viewer)

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Ivan1GFP

Tech Sergeant
1,847
797
Mar 19, 2008
Hello All,

Perhaps this is not the right place to begin this thread, but here goes:

The Ki-61-Ia was 8.740 meters in length. The Ki-61-I-KAIc was 8.940 meters in length.
Where was the extra length added and for what purpose?

I know there was a redesign that replaced the retractable tail wheel wit a non-retractable version and I suspect there was some change in the forward fuselage to be able to mount the Ho-5 cannons on the cowl.

Thanks in Advance.
- Ivan.
 
Length between the frames No 1 and 2 was extended 200mm as a new fuel tank was added behind the seat.

KI61_extended.JPG
 
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Hello Shinpachi,

Do you have any equivalent for the Ki-61-II?

- Ivan.
 
You are welcome, Ivan.
The profile of Ki-61-II was almost same as Ki-61-I-Tei(or 'd' or 'c kai').
Ki-61-II-Kai of early/later models was extended more approx 200mm.

ki_61_profiles_12compare02.JPG
 
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Here is what I have thus far.

I believe the dimensions on the Ki-61-II and -III are identical with a OAL of 9156.5 mm as compared to 8940 mm for the -I-KAI.

The length of various sections of the nose are defined. That makes the tail section considerably longer as well but I don't know WHERE the difference lies because I don't have any frame offsets.

- Ivan.
 

Attachments

  • Ki-61-I_Frames.jpg
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  • Ki-61-III_Dimensions.jpg
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The Ki-61-I from Main Spar to Tip of the Rudder is 5850 mm (Frame 2 seems to be offset by 50 mm from the centerline of the Main Spar) while the Ki-61-III (and presumably the -II as well) is 5930 mm for the corresponding dimension.

The question is where the difference lies.

- Ivan.
 
I think the length difference would have been lain everywhere.

Sorry but not only me but local researchers have no more detailed data about the fuselage modification but they say that the Ki-61-II-Kai(your III) was totally redesigned to take best harmony with the wing and the new engine. Having the same model name of Ki-61, Ki-61-II-Kai and its later version look a different fighter.
 
Hello Shinpachi,

My understanding was that the -II had a larger wing. The -II-KAI reverted to the original -I-KAI wing and the -III was the bubbletop.
Perhaps that isn't the full story?

I compared the -II frames (by eyeball of course) to the drawings of the -I and they LOOK about the same....

- Ivan.
 
I finally had a chance to scale up the attached drawings to 3004 pixels (30.04 feet == 9156.5 mm) and the results were somewhat surprising:

The distance between the Wing Spar and Tail is 5925 mm for the BubbleTop
and 5864 mm for the Razorback version.

Neither one agrees with the deduced dimension from the labels: 5955 mm.
The Razorback version lines up pretty well with the Ki-61-IKAI (5850 mm).
The BubbleTop version lines up pretty well with the Ki-100 Profile (5930 mm).

???
- Ivan.
 

Attachments

  • Ki61-II_Side_Reference.jpg
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  • Ki-61-III_Dimensions.jpg
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Hello Shinpachi,

I thought I had typed a reply but it seems to have been lost. I don't understand why the comparison was inappropriate.

My comparison was between drawings of a Razorback and Bubbletop Ki 61-II both of which are listed as 9156.5 mm in length. The problem is that the proportions between the drawings are different. Perhaps this is a bad assumption but my guess would have been that the nose portion of the aircraft would not have changed along with modifications to the rear fuselage. Perhaps that assumption was wrong?

- Ivan.
 
You have placed your full trust on the illustrators about their work accuracy but it is wrong.

Verify_Ki-61_illustration.JPG
 
Was going to say similar Shinpachi.
Ivan, drawings (being an artist's personal impression of a subject) often have minor mistakes and should never be taken as gospel. Even manufacturer's drawings are very often 'inaccurate' in various aspects, reflecting a basic design but not the physical modifications made to comply with manufacturing processes.

Some great info here anyway guys, thanks to you both!
 
Thanks Guys,

I believe I do understand the point you all are getting at. The problem is that if you can't find the data somewhere you need to use SOMETHING to work on a 3D model. That is pretty much what I am trying to do.

Here are the rules I try to follow:
1. A native measurement is preferred over a translated measurement: If the subject is Japanese, Italian, or German, Metric is the native measurement. If it is American, or British, then USUALLY Feet / Inch is the native measurement.
2. A non-rounded number is preferred over a rounded number. Thus 9156.5 mm is probably more correct than 9.16 meters.
3. An Explicitly labeled dimension is preferred over an implied dimension. Thus if they are the same (and this is not a certainty), the 5930 mm aft fuselage length on the Ki-100 is more likely than the 5955 mm length on the Ki-61-II.
4. If the dimensions are deduced by adding or subtracting from a base value, the calculation involving the fewest numbers is more likely to be correct.
5. The degree of confidence from lowest to highest is Paintings, Drawings, Photographs.

The attached screenshots show a model that was built using just a drawing. The dimensions are a bit off when compared to the drawings posted here. I am trying to convert this model to a Ki-61-II.

- Ivan.
 

Attachments

  • Ki61-1c_RBuzz.jpg
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  • Ki61-1c_Inverted_LA.jpg
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  • Ki61-KAIc.jpg
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