Twin 30 Cal Machine Guns

This is the part I've really been looking forward to... the Twin 30 Caliber Machine Guns for the rear gunner ring. I've always loved the look of those bad boys stickin' up out of the rear position of the SBD. As I mentioned earlier, these guns pivoted left and right with a 180 degree arc from port to starboard. They also could swing on the X-axis up to almost a one-o'clock position when pointed straight back, but had a slightly less practical angle when pointing straight out to either side.

This "flexible mount" stayed fixed at the rear most point of the turret ring, making it a true "tailgunner" vs a 360 degree gun turret. I decided I wanted my guns to rotate on both axis just like the real ones, which proved to add a little more complexity to the fabrication. I'll cover the fabrication of the guns on this page, and the ammo belts and installation will follow on the next page.

The Main Structure of the Guns I built the main structure of the guns by starting with two balsa blocks, and surfacing them with styrene sheeting. Next I laminated a piece of 1/8" or so balsa sheeting with 1/32" aircraft ply on both sides, then added 20mil styrene to both sides. This piece was then cut out to make the main riser that the guns would mount on. On the fullscale, this circular "donut" shape was part of a larger component that not only acted as the x-pivot point, but also had a chute to dispense the spent ammo shell casings. I drilled holes for both pivot axis to receive 3/16" dowel rods. The vertical dowel was glued in place, and the horizontal dowel spins freely inside a styrene tube that was sleeved into the drilled holes. It took me 3 tries at this component to get the proper thickness and offset from the ring that would put the guns where they needed to be. Next, to make the gun barrels, I used the same technique as I did on my 50 cal nose guns. This starts with an aluminum tube for the gun barrel, and then a styrene tube is cut for the outer sleeve and cooling holes are drilled. After this, additional barrel details are added from styrene & FliteMetal. The barrels are glued in place, then the two guns are glued onto the horizontal dowel rod to complete the functional assembly.

Secondary Structures & Components From here on out, I do repeated "detail passes" to add additional details and 3D surface relief. What details get added when depends on components left to be added, so you can "layer" your details on as needed. After my first detail pass, I made the "rack" that both guns mount onto in the fullscale SBD. This rack has a thin ply plate at the front, connected to a thicker plywood bar at the rear. Both of these were surfaced with styrene sheeting. They are connected by four styrene tubes with cross-members. The handles and other details are added to the rack to complete the structure. I later decided that I hadn't done a very good job of making the rear bar, giving me something that was a little out of position and out of shape. Therefore, later in my pics, you'll see I modified it to make it more scale accurate. This is what happens when you get "tunnel-vision" on one good photograph, and forget to check your other photos occasionally that show components from a different angle! Moving on, I started working on the two ammo belt infeed magazines. These circular apparatus stuck out of the sides of the guns and rotated to allow the ammo belts to always feed into the guns at an angle that points straight down to the ammo box. I wanted mine to be functional so they could rotate as well, but more importantly, I wanted them to be removable... I'll explain why on the next page. At any rate, to make them rotate and be removable, I glued Rare Earth Magnets into the magazine infeeds and guns that holds them firmly in place but allows them to rotate. Next, additional detail passes are done and I finished this phase up by building the iron counterbalance joiners at the rear of the guns. These were made from balsa stock, surfaced with 20mil styrene, and sanded to shape.

Armor Guard Plates & Final Details

With majority of the guns built and detailed, the next thing to do was add the protective armor guard plates/shields. There was one large one on top, with a hole cut out for the gunner to look through. There were also two more smaller shields that protected the gunner's hands... on each side of the guns. I made these by laminating a piece of 1/32" aircraft ply with styrene sheeting on both sides, then cutting and sanding them to shape.

The four large Phillips head screws were burnt into the front of the top shield (with brass tube and soldering iron), and the hex nuts were added to the back with styrene hex rod. The shields were glued in position and appropriate scale mounting brackets were made from styrene. Lastly, one more detail pass was done, which included the double thumb triggers at the rear. Pressing either of these linked triggers would fire both guns.

Paint & Weathering

Before painting, I shot the entire assembly with primer and checked it over for surface flaws and "ugly spots." After cleaning it up a little more, I then went over it with the glue hypo to add all the small screws and rivets.

Next, everything gets a base color coat with waterbased acrylic hobby paints. The shields/guards are Zinc Chromate Green, and the guns are my own recipe. I mix Flat Black, Gun Metal, Interior Black and a dab of Flat White to get my favorite "scale gun color." The remaining components were a Light Grey color, except for the rods, which were a natural steel color.

Once all base coats were dry, I began pulling out the 3D relief with dark washes and light drybrushing. The green shields also got some airbrushing to give the paint a more inconsistent fade and soiling effect.

The guns themselves had to be kept clean and operational in the field, so limited weathering was done to them. Mostly, I just did "3D relief enhancement" to pull out the surface details.

All finished and ready for the Ammo Belts...

Well finally here are the finished guns. Well, almost finished... I still have to build my two 30 cal ammo belts and install the guns onto the gunner ring. Once again, if you're keeping track, these guns finished up at only 1.2 ounces. Add that to my walls, ammo box, turret ring, etc., and I'm at right about 5-1/2 total ounces for a full-blown detailed rear gunner position. If I can get my gunner figure down to 2-1/2 to 3 ounces, that will put me at a little over 8 ounces of flying weight back there, which is well within my targeted goals.

That may seem like a lot, but I don't know anyone in their right mind that would build a scale SBD and not put at least a gunner bust, and some sort of crude gunner ring and twin guns in the rear position. Anything like that is going to weigh at least 4-6 ounces. So, I'm only a couple ounces more (if that), to have this fully detailed interior instead of a 1" deep interior with only a "bust" figure.

"Ammo Belts and Gun Installation"