G4M1-11 Front & rear guns.

[lyric1]

While looking for information on the KI-67 & its gun turrets I found some information on the Betty I thought I would share.
It seems that the nose turret on the front & rear rotated in addition to the guns slewing motion.
The front has a gun that pivots on a ball in the actual turret as well a motor powered & hand cranked turret.
Here is a view that you would recognize as in the AHII turret.The gun is fixed in a mounting ring at the bottom of the turret.



Now with this wrecked Betty the mounting ring is all of a sudden at the top of the turret.




Very obvious that the entire nose could turn to allow the gunner better arcs of defensive fire.

Here is a drawing I found online that I translated the parts about the turret turning.



窓手動旋回ハンドル = Window manually pivoting handle
窓旋回用モータ一 = Window turning motor one

Also the rear turned as well per this image.



Have not found an image of the interior view of a Betty through the nose cone. I did find one though from a Mitsubishi Ki-21 it also had a similar rotating nose turret.



Would be a benefit to find the actual gun arcs for this plane as it such a vulnerable aircraft to begin with. Since the AHII Betty seems to lack the defensive gun motion that the real aircraft had it is even more susceptible in game.

[lyric1]

Also the rear turned as well per this image.

Here is a view from the rear tail gun of the model #11.
You can tell it is a #11 by the slot at the top. The gun would raised into the slot for larger firing arcs when the turret needed to rotate 360 degrees.



In this video it shows a #22 model rear gun & you can get an idea how the mounting brackets of the gun would have worked on both models.
3min mark of video.
Couple of screen shots as well from the video.

http://cgi2.nhk.or.jp/shogenarchives/jpnews/movie.cgi?das_id=D0001300572_00000&seg_number=002

[lyric1]

A view from a Betty showing the nose cone & its rotation from the gunner pivoting it.

[lyric1]

Some info on the front gun from another book I have.




射界角 = Field of fire angle
前方回転銃座 = Forward rotation turret
固定状態 = Fixed state
1.5 番胴体肋材 = Turn fuselage ribbing?
固定締付 帯 = With fixed clamping band?
射撃状態 = Shooting state

One thing is for certain the field of fire on the AHII front turret is not even close to the drawing above. I believe the actual gun pivots on the ball close to 360 deg like the HE-111 video shows.
Then factor in the turret could spin 360 degrees as well on the Betty.

There must be a switch or button for the gunner to rotate the turret electronically at present not sure where that is.


https://www.youtube.com/watch?v=wBhGp23NS_s

[lyric1]

The rear gun seems to differ quite a bit to what we have in game as well.
Watching the video for the -22 model Betty the mounting bracket for the gun seems to be identical to the -11 model.

http://cgi2.nhk.or.jp/shogenarchives/jpnews/movie.cgi?das_id=D0001300572_00000&seg_number=002

So at present our AHII rear gun pivots in the vertical on the horizontal mounting bar.
Also the mounting bar system in game is fixed hard to the aircraft wall.





This seems to be incorrect per drawings from the same book that I used in the previous post on the front turret as well as the video. The gun is fixed onto the horizontal mounting bar & it doesn't seem to pivot vertically on the mounting bar like it is modeled in AHII  I could be wrong on this point hard to tell in the video for sure. The entire mounting bar system & seat all move as one part & its controlled by the gunner with his feet pushing back & forth on the foot rest. There is an attachment to the seat that travels under the floor of the aircraft that may have it under stress like a rubber band or a belt & pulley system to act as a counter weight that is shown with the green arrows as well as the foot rest. The red arrows show the seat/gun bracket/gun pivot point.

   




Sadly the video doesn't show an actual slew from left to right of the gun. However there must be a pivot point on that horizontal mounting bar to allow this to happen. I tried to translate the above drawing I struggled to get most of it correct. The best I came up with is whatever is acting as a counter weight/spring that is attached to the seat seems to be made of rubber.

Also have a drawing of the rear -11 model turret its on a bearing race & shows the large slot that the gun could move into. Plus there is small handles for a manual rotation of the turret by the gunner.




 

[lyric1]

 Plus there is small handles for a manual rotation of the turret by the gunner.

Seen here in this photo at the top of the turret either side of the gun.

[lyric1]

Bought an English printed book on the Betty. It has a poster in it that contradicts the Japanese drawings I have posted before in this thread at least with the vertical movement of the rear gun.
The drawing below shows 55 degrees of slew in vertical & nothing shown in the horizontal slew.  Have to wonder if they didn't show this was due to the fact the rear turret could be spun 360 degrees & with the turret slot of the -11 rear gun. Maybe it could fire a full circular motion at 55 degrees so long as the gun was in the slot?



Also the -11 had two variations of rear turrets the cone shaped version with the slot. Then a later variant where a portion of the glazing was removed & still kept the slot to help with improving the gunners ease of firing. You can see that above in the drawing as well as the images below.









If the rear guns on the Betty do get corrected the chopped version of glazing with the slot maybe the better option I think.

[lyric1]

The rear gun on the real Betty has puzzled me for a while in particular the horizontal bar the gun was mounted on.
Plus what is the handle looking thing below the bar?








The handle had to serve some purpose but what.
As a machinist by trade to me the horizontal bar looked like slides of the beds of machines I have used. I suspected that the handle looking thing below the horizontal bar is just that a hinged handle & locking mechanism,when the rear gunner needed to slide the gun from left to right he pulled back on the handle that unlocked it from the bar. Then he could pull it either direction while the handle was deployed.

The Japanese drawing I posted before sort of hints that the gun slid from side to side. However not a lot of detail explaining if this was so.



I have been looking for a while for some photos showing the gun mounting block either side of the center line of the aircraft to verify if the gun did slide on this bar.
Tonight I did find such images.
They are from a wrecked -11 late version with the modified rear turret.

Rear view looking out.



Looking in.


 



As you can see pushed all the way over to one side is the mounting block of the gun. I believe you can also see the pivot pin the gun would have been used to slew left to right on the top of the block.



Also you can see the remains of the barrel as well as one of the handles the gunner would have used to spin the turret.
The mounting holes the other handles would have been in are also visible.





http://www.aviationarchaeology.com/src/Yap/site4betty.htm

One thing is for certain Japanese turrets from this era where difficult to use compared to allied versions.
The rear gunner had to use his feet to get the vertical slew,he also had to turn the turret by hand to get the full arc of the gun if needed by placing the gun in the slot. Then also had to unlock the gun from the mounting bar to get his full range of motion on the horizontal slew then pivot the gun on the mounting block as well.

[lyric1]

The gun is fixed onto the horizontal mounting bar & it doesn't seem to pivot vertically on the mounting bar like it is modeled in AHII  I could be wrong on this point hard to tell in the video for sure.

I can say with certainty now that the horizontal bar that the rear gun slides on is fixed solid & there is no rotation at all of it. I found some images of Yamamoto's Betty as well as some other wrecks that show some detail of the mounting cradle.

In this picture you can see that the round portion of the Aluminium looking bracket to the right is pinned into position with some sort of domed dowel pins.



Another view showing the rolled steel tubing frame of the gunners cradle. There is another part welded on the end of the tube & that is what Aluminium part is pinned to. When you look inside the Aluminium block or the gun mounting block as I call it. You can see the locking pins that grabbed the bar & slid on the horizontal bar after the locking handle is released .
The handle is not visible on this wreck.



Another angle.
Here you can see the mating part to the round pinned bracket & its clearly all one part on the horizontal bar with the square flange on each end & then is all bolted together.
So it didn't rotate as we have in game now.




This is the 20 mm cannon that was used on the rear.



If you look just above the pivot pin there is cone shaped part that has a good matching radius to the photo I posted before showing the pivot pin in the gun mounting block from a different wreck where the cannon had rusted away.





Proof at least the cannon did pivot on the mounting block I think.

Same wreck different time frame.



In these two you can see the gunners seat.





Great view of the brackets & mounting methods used for the gunners cradle.
The seat portion is missing on this wreck.
Also quite a few handle pins for spinning the turret visible in this image.



Video of the Yamamoto wreck.

https://www.youtube.com/watch?v=4Q_Io28IO3w

[Blade]

to Lyric1

[lyric1]

to Lyric1
(Image removed from quote.)

Thank you Blade for the translation.



The image is the best I have found for the rear gun cradle. Its not 100 % accurate there is some cross member parts missing. It definitively contradicts the previous drawings showing a pulley system attached to the seat.   The turret in the image above & below is for the -22 AHII turret is a -11.



You can see the spring attachments & brackets in these photos.

[lyric1]

Some nice photos of the nose turret of the only restoration of a Betty in the world.











Also found a couple of images of a wrecked Betty's -11's modified late version rear turret. It is the first images I have found where the slot is not set at vertical proof that it did rotate.





Also a drawing of the different types of rear turrets used on the Betty over its life time.



This drawing is not from Betty it is though the correct nose gun & ball mount used.


 

[lyric1]

Bought some Japanese magazines on the Betty found an interesting image in one of them.



Rather strange the handle for locking the gun in place on the horizontal bar was operated by foot?

Also the image that Blade translated was of poor quality & some of the Japanese text was not legible. The magazine I bought also has it so I translated the text & it's a foot lever.

[Mister Fork]

Gonna have to ask - have we modeled the rear gun on the Betty properly then?

[lyric1]

Gonna have to ask - have we modeled the rear gun on the Betty properly then?

Simply put no.
Finding information is difficult most of the info that is most likely correct is in Japanese. So the language & translation of info is tough. Plus the -11 model had two variations of the rear turret. The rear gunners cradle operated the same for the most part from what I can tell. The front & rear turrets rotated AHII turrets on the Betty do not. This was what motivated me because defensive gunning in these aircraft was hard & just seemed wrong.

Plus there is a number of publications that in the very same book contradict themselves from one page to the very next. For example gun firing arcs of the rear gun.

This image shows on the horizontal slew of 35 degrees.



Then a few pages away another image showing 40 degrees.



This is the problem what to choose? Hitech creations chose what information they had on hand I would guess.
The issue I think is that a number of the publications did not know the rear turret we have in game is a late version modified -11 turret & it rotated like the early version -11 turret a total of 360 degrees.

What is incorrect with the AHII rear turret is we don't have the double gap designed where the gun barrel would have moved into them then moved with the rotation to give a larger firing arc when rotated 360 degrees.

This image shows clearly in the drawing as well as a photo that the front gun turret was rotated.



Then when you look at the drawing below for the movement of the front machine gun it shows the range of motion in degrees & the drawing has more motion than what we have in AHII right now. But no mention of the turret spinning 360 degrees.



Even the above image contradicts another Japanese drawing I posted before of the degrees of motion.




Anyways just a hint of the problems the creators of the game had trying to figure all this out. Newer books are out & the information is changing as well as more is known. Still working on the new magazines I bought there is some new photos in them I have not seen before that I am figuring out.
So stay tuned.