< 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.
