< Bogie Truck 2 >
Four wheels for the bogie truck were painted with stove enamel which was used for the William. Before painting, whole job was scrubbed by wire brush and degreased by acetone. Then, roughly masking bosses and rims with card boards, I sprayed twice for each side.
After that, the rim and the boss were sanded in the lathe, so as to define boundary of the paint.
O.D. of the axle blank is 20 mm, which is bigger than the lathe headstock's I.D. Therefore I employed 'fixed steady' to turn the axles. The wheels were glued onto the axles with Loctite.
The photo shows laser-cut equalizers put back to back. Note subtle swells at the middle. The bends were done as follows.
I prepared a bending jig from round and rectangle rods. The jig is put between large vise jaws. As I squeeze the vise, first the rectangle and inner two round rods catch the job and bend to V-shape, then the outer two round rods push the outer area to opposite side. When the both ends become straight again, the process is completed.
The equalizer and leaf springs are assembled with eye bolts, pins and nuts, same as the main chassis' springs.
The photo shows side control assy. The sliding pedestal is made from gunmetal casting, which is secured in rectangle cavity of the bogie center casting and can move right and left. Four coil springs push the pedestal from both sides.
The coil springs are made of hard stainless wire, coiled in the lathe. Note the start diameter is smaller than the rest, for the following reason.
So as to keep the springs from coming off, left and right coils are combined with screw, nut and rings. The sliding pedestal is drilled to a desired depth from both sides, then small hole for the screw is opened through the block.
All of components for the bogie truck were assembled.
The bogie truck is engaged with the stretcher casting of the main chassis. The center pin is only for keeping the bogie truck from drop. I inserted a spacer between the sliding pedestal and the stretcher, for adjusting the bogie truck's height. The thickness of the spacer will be optimized when I finish the loco.