< Brake System 2 >
There are two kinds of brake beam hangers. They are made of cast iron. The photo shows hangers for 1st and 2nd driving wheels, cut to desired thickness and drilled connecting holes.
This is a cast iron for the 3rd hangers.
The bottom face is cleaned in four-jaw. The face become outside of the hanger. After that the inside is finished by milling.
Holes for pins are opened and the outside curved face is cut in the rotary table.
Finally the bottom slit is cut by milling.
The brake beam is made from laser-cut steel plate and steel stud. They are silver-soldered together. Incidentally, full size brake beam is provided as a unified cast iron.
The photo shows linkage parts for the brake beam. They are the smallest castings that I've ever ordered.
The bolting face is cleaned. And then the rink hole is opened as the photo shows.
Assembled brake beams. The larger one is for the 3rd driving wheels.
The levers for linkage are laser-cut steel plate with drilled holes. Two of them have phosphor bronze bushes. They are not for anti wearing but as spacers on both sides.
Pins for linkage are made from steel rod. They are fixed with cotter pins. It needs 37 pins for the brake system assembly.
Following the prototype, angle of each brake shoe is adjustable with a leaf spring and push bolt. The photo shows parts for adjustment. The leaf springs are made from 0.5mm phosphor bronze plate. They have two kinds of profile. The hollowed bushes secure the springs around the brake shoe pins. The brass angles are brackets for push bolts.
The photo shows assembled parts for 1st and 2nd brake shoes. The left one shows a view from the inside. One end of the spring holds the brake shoe, while the other end is push by the adjusting bolt.
The adjusting bolts for the 3rd brake shoes are secured onto the brake beam, instead of brake beam hangers. Of course the brake beam always has to be kept horizontal. There are some parts for the purpose. I will introduce in the next time.
The brake link system is assembled without the hangers.