How to build a T3 - Part 6
Step 12: The cab and bunkers
Now the basics of the boiler are in place, we can have a look at the cab. The most obvious omissions at present are the windows in the front and rear walls, and the door openings at the sides. Lets take the sides first.
The upper part of the opening runs from H=221 to 319, L=670 to 752. I'm going to use a prefabricated window frame generated with a spreadsheet (see the FAQ's and Tips section in the User Guide).
As well as the window frame, this gives me a dummy panel to use as a cut-out mask. By pasting this into the file immediately after the cab side panel, I can use the Cut-Out tool to make a hole in the cab wall.
As usual, the cut-out tool manages to reverse all the panels, so I have to follow it up with a Reverse Panels.
Then, the panel under the opening can be subdidvided to make the cab half-door. Use the Divide Panel tool to cut the panel at L=687 and 737, and shift the piece we cut out inwards by 6 cm. The gaps are filled by small panels in a different colour.
Of course, now we can see into the cab, we shall have to make the cab walls visible from the inside as well. We could do this by using the "=" modifier on all the panels, but that would make the inside the same colour as the outside. Better is to make a second copy of the panels, facing the opposite way. A simple Reflect W will do this. You can then change the colours of the inward-facing panels to a lighter shade. Don't forget that interior panels should always be set to "[D3D]".
A useful dodge with interior walls is to make them 3cm shorter than the outside walls, otherwise they can sometimes "show through." This is more of a problem if you are using incandescent panels for the interior, but we don't need these for a steam loco cab.
The spectacles (round windows in thhe front and rear cab walls) are always a nuisance to make. Those on the T3 have the added complication that they consist of two semicircles with a straight part in between. The easiest way is to make a rectangular cutout, then use the cylinder tool to make the basic shape of the frame, and manually transform the end of the cylinder to make the fill-in around it. An important tip: use a number of segments that is a multiple of four, so that you can work on one quadrant and make the others by reflecting it.
Taking the rear wall first, as it's easiest to see what we're doing:
Make a cut-out from W=70 to 120, H=228 to 310
Make a cylinder (cylinder and one end) at W=95, H=285, L=796 to 790, R=25. The end colour should be the same as the cab rear wall. Discard all but one quadrant (I used the top outer one), and make sure the panels are oriented so that the frame is visible from the inside and the end from the rear.
#spectacle Fill 95/796/285 95/796/285 120/796/285 118/796/294 35:45:45 [back] $ Fill 95/796/285 95/796/285 118/796/294 112/796/302 35:45:45 [back] $ Fill 95/796/285 95/796/285 112/796/302 104/796/308 35:45:45 [back] $ Fill 95/796/285 95/796/285 104/796/308 95/796/309 35:45:45 [back] $ Fill 120/796/285 118/796/294 118/790/294 120/790/285 65:65:65 [D3D] $ Fill 118/796/294 112/796/302 112/790/302 118/790/294 65:65:65 [D3D] $ Fill 112/796/302 104/796/308 104/790/308 112/790/302 65:65:65 [D3D] $ Fill 104/796/308 95/796/309 95/790/309 104/790/308 65:65:65 [D3D] $
Now use a search and replace to change 95/796/285 95/796/285 to 120/796/310 120/796/310. If the panels disappear, do a Reverse Panels.
If there are any gaps, you may have to make a little manual correction. Then make tha other three corners of the spectacle by reflection, and fill in the two vertical frame panels by hand.
TIP: I used a 16 step cylinder. There are four spectacles, and each of them has eight of these corners (four inside and four outside), each containing four triangular panels. Thus it is well worth taking a moment or two to combine the four triangles we have made into two quadrilaterals: a total saving of 64 panels! A bonus is that triangles sometimes do strange things to the lighting: it's better to replace them with quadrilaterals where possible.
You can use the cylinder tool with the same parameters as before to add glazing (make this visible from the outside only: it's an irritation in the cab view, otherwise). Reflect in width to make the other spectacle, then make an interior as for the side walls.
The cab front wall can - for the moment - be simply a reflection of the rear wall.
Now we know where the windows are, we can add the "Cab" keywords to the file header. The position is that of the driver's eyes, so we can set it on the centreline of the right-hand spectacles, with the length about halfway through the cab:
Cab -95/690/270 Cab2 -95/690/270
...we can always make fine adjustments to this later.
The cab roof has a cross-section in the form of an arc of a circle. In theory, we can simply build this by using the cylinder tool and discard the segments we don't need. The arc measures +/- 10 degrees, R=727, centre is at H=-386.
10 degrees is 1/36 of a circle, so if we want each side of the roof to have four segments, we need 4x36=144 segments in the cylinder. This is a lot, so it's advisable to do it in a new, temporary file. It doesn't take long to find the lines we want and copy them to the main file. We need the cylinder itself (make it a bit longer than the cab, and make the parts double-sided so that we can see the overhang) and the two ends, which form the rounded tops of the front and rear walls. You will need to change the apex of the triangles from 0/L/-386 to 0/L/324 using search and replace, of course.
There's no need to discard the flat "roof" of the original mock-up: reverse and make it a lighter colour, and it serves as a cab ceiling, saving the need to repeat the curved wall tops on the inside.
We can add the rooftop vent (just a couple of stacked boxes) at the same time.
Download the model at this stage
Next: Buffer beams and underframe detail