Switched from Rhino3d 4.0 to Rhino 5.0 beta. The new software is 64 bit. It really helps make the larger files in this project more manageable.
Today I installed the engine and the gear train, so finally we have an overview of the turret elevating and drive machinery. This would be how it looked under construction, around Thanksgiving, 1861. The point of view is looking forward and up from a vantage point below the ship's galley area. I turned off the steel bulkhead for visibility. The longitudinal metal beam seen above the deck beams is the floor beam of the turret.
Attachment:
overview 2-19-12.jpg [ 52.8 KiB | Viewed 3610 times ]
The height of the engines within the gearbox is fixed by the position of the crankshaft throw. This is a position we can find on good, clear drawings. Here is a glimpse of the two connecting rods, now in place on the crankshaft. I treated the V-twin engine as a "group" and positioned the whole assembly, vertically, using the crank throw, at the left of this image.
Attachment:
height defined by con rods.jpg [ 92.54 KiB | Viewed 3610 times ]
It was a pleasant surprise to find that the top of the frame of the portside cylinder fit precisely to the bottoms of the overhead deck beams. Bear in mind that we are fitting a USS Monadnock turret engine into the USS Monitor, on the assumption that the two engines are very similar. In fact, the Monadnock engine fit into place very well, perhaps exactly.
Attachment:
engine frame fits to deck beam.jpg [ 68.89 KiB | Viewed 3610 times ]
From the McCord collection, it is clear that the bore and stroke of the Monitor's turret engines were 12" and 16", respectively. Yet in some 1997 CAD illustrations of the turret engine, we find cartoonish cylinders with tiny diameters. I got another clue today about why these artists drew such skinny cylinders. It turns out that if you view the whole assembly from the top, this is what you see:
Attachment:
apparent microcylinders.jpg [ 78.62 KiB | Viewed 3610 times ]
The hole in the engine frame in effect crops our view of the cylinders from above, so that they appear to be long and skinny. If you were working from a murky overhead view, it would be easy to assume the edges of the hole in the frame were the edges of the cylinders. In fact, seen whole from below, the cylinders are robust. They look like this:
Attachment:
clear view 12-inch cylinders.jpg [ 74.29 KiB | Viewed 3610 times ]
It was sort of amazing to see how everything fit together without physical interference. I was worried the valve gear, which is all over the place, might be snagged by a gear, but there are no such problems. The system needs bearings next, and framing. Two vertical stanchions flanked the crankcase on either side. Ericsson used them to support the weight amidships of the crankcase, gearbox and spur gear -- and he also used them to form the legs of the galley stove.