< Parts for the Main Frames >
The full size cylinder block is straight bolted across the main frames. However, for easier assembly, I prepared a cast iron stretcher - green one in the CG - between the frames and the cylinder block. The stretcher also holds the leading truck.
After facing off the top surface in four-jaw, the both sides were milled to a desired width. Next, the spigot for the leading truck was turned in four-jaw. To find the center, I glued a small brass sheet on the spigot and scribed the center on the sheet. Before cutting, the sheet was removed. Finally, center screw hole for leading truck pin was opened. The photo shows the final operation.
The photo shows a view from bottom. Note the casting is fixed with counter-sink screws, because the cylinder block will sit astride the casting and cover the outside faces of the frames.
These are cast iron brackets for many kinds of links. Left pair are brake lever brackets, right top pair are front equalizer brackets, and right bottom pair are back equalizer brackets. Regarding brake lever brackets, I already introduced laser-cut brake lever brackets, but now I replaced them with cast iron parts which can hold the brake levers firmly with slits. As castings, there is no slit yet. So I have to cut many slits for them. I started with the front equalizer brackets.
The illustration shows front section around the front equalizer brackets. The four squares (green) show main frames. The brackets (red) are bolted onto the frames and have inside and outside slits. The outside slits hold brake hungers (cyan) while the inside slits hold equalizer arms (blue).
First I cut bolting faces and steps with an endmill, and then drilled holes for screws and pins.
Both inside and outside slits were cut in a time. Note the chucking strength is dealt to the root of the slits, so as to avoid the slack of the chuck.
Small screw holes across the pin bush were opened. These are for securing the large pins.
The castings were bolted onto the frames. Due to a mistake of cast designing, I had to pack brass plates between the upper frame's bottom and the casting's top. The brass plates were fixed with pins onto the casting.
The back equalizer brackets are still more difficult to chuck. When cutting bolting faces, I clamped with three bars and removed one by one. I mean the job was always held by two bars of the three.
The outside slit is V-shape slit. So the casting was tilt and cut from both sides.
It is unhappy finish with unstable cutting. I accept it because the damage is only at the inside.
They were bolted onto the frames, too. Note the screws come from inside of the frames, so as to secure enough clearance for driving wheels. A boiler barrel holder plate was fitted right above the equalizer brackets.
The brake lever brackets have only inside slits. The slits have 'mushroom' shape. First I cut oval holes from the side, and then cut square slits from the bottom.
The brackets were bolted on inside faces of the frames. The photo shows view from underneath. They were combined each other with a round bar stretcher.