Andy,
Thanks once more for sending the extra shots of the ammo feed system and the diagram of the inner structure. Both were very useful.
Glen, good to see you drop in again. That's very interesting on the B-24. A long time ago I built the B-17 and B-24 and I was thinking as I built the Lanc turret that I had no idea how the US aircraft tackled the same problem. I could only assume that they had a system similar to the German interupter system that allowed the Luftwaffe to fire through their spinning props. I assume that the system you mention was an electronic one?
Anyway, back to the build. After a lot of trial and error I have finished the basic structure for my turret and have arrived at the point that I need to paint before I can complete the interior.
You may be able to make out that I tried to add something that resemble the gun sight rocking arms to the inner gun mount support. Andy's diagram was very helpful in working out the mechanics for this. An oxygen regulator has also been added to the front of the turret.
At the back, the gunner's firing control yolk and an instrument dashboard are installed. I should say that this is still a test fit, as I need to paint some of these assemblies before they are permanently fitted.
Having seen the photo, I'm unhappy with the thickness of the seat. It looked fine life size but I think I'll have a look at somthing thinner before I fix it in place.
I next tackled the gun mounts.
I needed to lose the large piece of plastic connecting the breeches at the back but first I needed something to tie the two sets of guns together so they would continue to move in sync with each other when the connection was gone.
Here's where I took some 'modeller's licence'. The gun sight mount is really connected to the rocking arms as per Andy's diagram, however, by connecting it directly to the gun mounts, it fulfilled the purpose of holding the two mounts in sync and also allowed the sight to follow the gun trajectories. It would have been static otherwise.
Next, the two outer breeches were added making sure that they sat slightly higher than the two inner guns. As you can see, I needed to pin these in position with brass rod and some filling was required to tie them into the mounts. The central elevating axel is there to afford some stability while I'm still working but I should be able to lose it when they're permanently mounted.
After mounting the scratch-built gun sight I set about adding the replacement Master Brass gun barrels. This just needed some care and patience. They needed to be accurately positioned on three planes: First, from the top, they needed to line up with their breeches and be parallel to each other. Then, from both sides the height difference from the outer and inner guns needed to be apparent and they needed to be in line with their breeches horizontially. Finally, from a viewpoint looking straight down the barrels, the height and separation between the inner and outer guns needed to look consistant.
To achieve this was slow and painstaking as the pre-drilled holes in the mounts were sized for the fatter plastic barrels supplied. The brass mounts were too thin to fit snugly in the receiving holes, so each gun had to be held and manipulated to the correct position as the glue hardened and only when fully set could I move on to the next one.
We'll end with a couple of shots of the whole assembly, so far, test mounted.
Most importantly, the elevation of the guns isn't impeded by any of the other equipment. This was always a nagging worry during the build.
The only other thing of note is, on the triangular supports on the outer mount frames, I replaced my badly freehand cut plastic circles with brass discs that I drilled through out through their centres. I think the effort was worthwhile, as they look a lot better. There are two bracing struts from the seat to the inner gunpoint supports, these will probably be the last things installed.
That's it for now. I'll paint and finish the interior and get on to trying to salvage the canopy.
Until next time , best regards,
Gerry