G4M1-11 Front & rear guns.

[Chalenge]

Lyric you can clearly make out the gear teeth in these two images. Amazing research you have accomplished here.

[lyric1]

Lyric you can clearly make out the gear teeth in these two images. Amazing research you have accomplished here.

(Image removed from quote.)

(Image removed from quote.)

Thank you.

Not sure if the Japanese restoration of this Betty is to get an operational aircraft or a static display. They seem to be working to get it as close to correct as possible though.

https://www.google.co.jp/search?q=%E4%B8%80%E5%BC%8F%E9%99%B8%E4%B8%8A%E6%94%BB%E6%92%83%E6%A9%9F%E6%B2%B3%E5%8F%A3%E6%B9%96%E8%87%AA%E5%8B%95%E8%BB%8A%E5%8D%9A%E7%89%A9%E9%A4%A8&biw=1097&bih=623&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiZk-_y8IHMAhWJ6SYKHVWfAc8Q_AUIBigB#imgrc=_

[lyric1]

Drawing showing front turret & it's gun at 12 o'clock.



Photo of the front turret gun at about 2 o'clock.



Best image I have found of the rear -11 late modified turret from WWII.

[lyric1]

Little off topic.
Wonder if HTC can model this in?

[Volron]

 

[lyric1]

Translated a few more things that could not be read before.





For some reason Google translate wont complete this one?

[lyric1]

Looking at this image for a bit & noticed the drawing shows a vertical pivot point on the adjustable gun mounting block.



This seemed strange. 
So did some digging to see if the drawing is correct because it would change the entire vertical slew of the gun if it is.
Here is a few pictures of the Type 99 Mk-1 20mm cannon. There is two basic types of this gun fixed & flexible. What we have in the Betty is of course flexible.

Below is the fixed type used in the Zero for example. The tabs on the underside of the gun I believe is one of the mounting points.





Here is the flexible.













Based off the above photos it looks like the bracket that attaches the gun sight also has the pivot point attachment as well.

Without question the drawing is wrong there is no vertical slew with this arrangement. An added bonus of pushing the pivot point forward it creates more space between the ammo drum & the horizontal gun mounting bar. This will allow more horizontal slewing of the gun to give a larger firing arc because I believe the ammo drum is the limiting factor of that left to right motion.

[lyric1]

This is what we have in game now with the rear gun of the Betty.





Approximately 30 degrees of slew either side of the aircraft center line.

Big thanks to Challange for the overlay images from my screenshots & other things in this thread he helped with .

OK where to go now?
This image below I think has all the answers I have been talking about in this thread.
Its a grainy washed out photo. That aside it still shows some interesting points about the rear turret of the Betty.



First off we have a -11 late modified rear turret similar to what is in game now. You can tell its the late version because the cone portion glazing of the early -11 turret is missing & there is a gap in in the turret at about 1 o'clock. There is a second gap at about 7 o'clock that is hidden by the gunner.

Proof positive from this image the turret did turn it's clearly visible with the gap being right of center as well as two handles being visible the gunner would grab to spin it. Also another fact that can be seen the gun has been slid to the right of the center line of the aircraft. By the looks of it can still slide some more to the right as well along the horizontal mounting bracket.

Since there is no inner turret ring at the 1 o'clock position the gun has been swung up into that space. Since the gun can still move right it can increase the firing arc as the turret rotates to 3 o'clock position.

What is the angle the gun is at now in the photo?
Since the gun pivot pin is not visible in this image & using the photos I have posted previously of the 20mm cannon I can get very close to where it would be.

I enlarged the photo & rotated the image to get the gun venting slots horizontal to establish my horizontal line & placed the line approximately center of the venting slots . Reason i did that was because the pivot pin would be at right angles to the slots. The vertical line is set off the approximate position of the pivot pin.




I don't have software for figuring angles on my PC so I just used one of these & placed it on my screen.



Using the bottom of the horizontal grab bar that was used by the gunner to get in & out of the gunners cradle. That is the part my yellow vertical line intersects with at the top of the image.

I get 65 degrees.
Can the gun pivot more than that to get a larger angle? I think this might be as about as much it could do because of the ammo drum hitting the horizontal gun mounting bar.

I think that is about it on the rear gun of the Betty right now that's all I have.
Let the debate begin.

[lyric1]

Nice view of a similar front machine gun turret like the Betty. Same gun used though in these two images like the Betty.





Rear horizontal mounting bar with the gun mounting block & pivot pin clearly visible on this wreck.



Should start a new thread on the other guns on the Betty and those issues as well
Or just go with it in here

Similar set up on the side fuselage guns a release handle to slide the gun from side to side to maximize firing arcs.

[Brooke]

Excellent pics you folks have posted, too. 

[lyric1]

Should start a new thread on the other guns on the Betty and those issues as well
Or just go with it in here

Similar set up on the side fuselage guns a release handle to slide the gun from side to side to maximize firing arcs.

Go with it in here.

As I have pointed out in this thread that the AHII Betty forward & rear guns are not historically correct. Due to this fact they are woefully inhibited in terms of the firing arcs they could achieve. Therefore far easier meat on the table in AHII than what they were in real life. 
The remaining guns are not correct either so lets look at the waist guns next.

First off a view from the left side gun & the total amount of forward movement it has. At present the AHII Betty has no ability to fire forward at all. At best it can get 90 degrees to the center line of the fuselage as can be seen in the image below.



All drawings I can find show that the waist gunners could actually fire forward of the aircraft.







So how is that possible? The waist guns like the rear gun slides on a rail & can be unlocked by the gunner. The first images at the top of this post show the release handle to slide them back & forth. Our current set up in AHII has them fixed in one place. If we could slide them on the rail towards the rear of the plane it allows the gun to pivot forward now that the remaining turret blister is no longer in the way.

An image showing the gunner removing the side blister it rotates out of the way & then it would be hung nearby as can be seen in the photos below or just left on the floor.







Also the AHII waist guns dont seem to point down or up far enough compared to a drawing I have. The AHII screenshots shows the maximum vertical slew upwards & downwards.







At some point I am guessing they did away with the locking handle & made some king of switch arrangement that would make it easier to unlock the gun to move it based off of the above drawing.

[lyric1]

Another waist gunner view.
The gun support rod is prominent in this image.

[lyric1]

Another waist gunner image in this one the turret blister is still attached.
Also this gun has the wired switch instead of the release handle on the sliding rod.

[lyric1]

Dorsal gun drawings.

Just like the waist guns the turret blister can rotate open & closed. When it rotates downwards into the aircraft it stays in that position & doesn't detach like the waist gun blisters.

As you can see the gun is mounted on the center of a horizontal rail & has 70 degrees of vertical slew upwards. No angle in any drawings I have gives the angle of slew from left to right.





Views of the AHII Dorsal gun.

These two views show the center gun location on the bar & maximum left to right slew of the dorsal gun.





Over head view of AHII Dorsal gun maximum horizontal slew.





The above images give us a very close example of modeling of the AHII dorsal gun's horizontal slew compared to the drawings.
Is it right though?

Side views of the Dorsal gun with the F3 mode.





Depending on where I locate my pivot point on the dorsal gun I only get about 40-50 Degrees of vertical slew upwards?
Long way short of the 70 degrees in the drawings.

So why?

Well it looks like the position of the gun is set too far back into the aircraft.

Note the location of the ammo drum in these images.

Drawings.





AHII Screen shots.





As you can see in the above images the AHII ammo drum appears in the window on the forward part of the turret where in the drawings it's not.
So the horizontal mounting bar is not far enough towards the rear of the plane to allow the gun to pivot upwards to 70 degrees as it should.

Here is a view from inside of a Betty showing the center mount location of the dorsal gun.


Now here is a drawing showing the gun slid all the way across the horizontal mounting bar.



Fair enough that drawing proves nothing. All I need is a photo showing that it can move.
I have that as well. Its the same as every gun in the Betty except the forward turret. It uses a mounting bar that the gun can slide on & can be locked into the position the gunner needs.



Since this gun can also slide on the horizontal mounting bar. It looks like in the above image the gunner can get very close to 90 degrees of horizontal slew from left to right off of the center line of the aircraft.

Proving the old Japanese drawings I posted from the 1970's are wrong about this gun on a number of points.

[EskimoJoe]

Lyric1, the depth of your research is intriguing and almost frightening 

Since I'm limited to about 30kb/s internet speed where I'm currently at, another avenue of approach I'd like to suggest you might like to try is seeing if there are any good pictures of G4M wrecks in the Aleutian Islands of Alaska, or 'Aleutians'. A lot of equipment was left pretty well preserved on the islands of Attu and Kiska, and I believe some wreckages on other nearby islands might have been preserved and maybe even documented.

Just a thought, although it seems like you have more than enough sources to contend with