< Bogie Truck 1 >
The bogie truck is a variety of Adams type. It is made from castings and laser-cut steel plates. The photo shows all of castings for it. A center casting, horns and stretchers are cast iron, while axleboxes and a sliding pedestal are cast gunmetal. The iron castings were annealed in electric furnace. The surface rust can be removed in a manner of bicycle cleaning. Pour thin oil freely, scrub by steel brush, and wipe of with a rag.
The center casting was cut by milling machine. All manner of cutting were controlled by x-y-z coordinates.
Next job is the axleboxes. First, in the four-jaw, the outer face is finished. Then reversing chuck, the inner face and bore is finished.
In order to cut symmetrical side grooves, a blank axle is passed through the axlebox and the axle is supported by V blocks at both ends. Then the axlebox is chuck in a vise. After finishing one side, the job is turned over and chucked again. Thus the both grooves can be cut in the same distance from the axle. After that, the vise is slightly tilted from square to cut X-shape flanges.
Top face of the axlebox is rounded. It is finished in the rotary table. The photos show rotary table setup without and with an axlebox.
Finally top grooves are cut and the axleboxes are completed. The top groove is to clear the top member of the frames.
The cast iron horns were cut. After cleaning bottom face in the lathe, the top face was cut to a desired thickness as the photo shows.
Upper and lower bolting faces were finished truly square to the side sliding face.
The center casting and outer horns are bolted to laser-cut top frames. Then the outer horns are spaced by the stretchers.
An inner horn is positioned by an axlebox. Note a piece of paper is shimmed between them, so as to allow axlebox's side play.
A thick plate was firmly bolted under the center casting. The plate will hold the sliding pedestal, that is, all of bogie axle weight. The oval hole is to allow the pivot pin's side play.
Bolting the lower frames, then the bogie chassis is completed. It looks a little delicate but no problem because the axle weight will charge just onto the center casting and axleboxes, not onto the frames.