Ore Cars Step 15 – Mechanical Brake Parts

In the previous post, I described how I built the air brake components for the ore cars.  In this installment, I’ll describe how I represented the moving parts of the brake system on each car.

There are many moving parts in a freight car braking system.  The kit greatly simplifies everything to incorporate only the largest parts.  The floor of these ore cars sits very high and leaves the space between the trucks visible, so some brake parts are necessary.  I think the parts included with the kit amount to an appropriate level of detail, so that’s how I proceeded.

The two largest visible moving parts of the brake system are the cylinder lever and the fulcrumed lever.  Basically, the brake cylinder moves a lever that balances across the slack adjuster.  The slack adjuster runs down the middle of the car between the two levers.  On the real car, this part is a bit bigger because it has mechanism that adjusts for wear on the brake shoes.  The movement on the opposite side of the cylinder lever moves a rod that transfers movement to the linkages in the “B” truck.  Incidentally, the brake wheel is attached by rods and chains to pull on the cylinder end of this lever, manually actuating the brake mechanism.

At the “A” end of the car, the fulcrumed lever pivots on one end and moves the rods connected to the brakes in the “A” truck.  The slack adjuster mounts at roughly the middle of the fulcrumed lever.

I started by drilling out the marked hole in both levers with a #80 drill. I didn’t drill out the holes in the ends of the levers because the cast-in dimples were not close enough to the middle to prevent the drill bit from creating an open slot instead of a hole.

Again, to help hold onto the parts, I left them connected together on the resin sheet. Once they were drilled and cut from the sheet, I stockpiled them, sorted by size (the brake cylinder lever is longer).

On the real ore cars, these levers move within a channel suspended beneath the car.  This is represented by scale 18″ wire grab irons.  I marked the locations for three of these on the center beam with drafting dividers and drilled them out with a #80 drill.  I made an  .080 inch thick spacer by laminating two pieces of styrene.  This helped to keep the parts evenly off-set from the center beam.  The image below shows the spacer in place for clarity.

After I’d glued the wire parts, I went back through the assembly line and glued the clevis directly onto the end of the brake cylinder, and then glued each of levers into their corresponding guides.  It’s not really clear, but in this shot, the brake cylinder lever is in place.

In the next shot, you can see both levers have been glued in place.

With the levers in place, I measured and cut a piece of .015″ steel wire to represent the slack adjuster.  I used two pieces of .015″ brass wire to represent the rods that go to the “B” truck and the brake wheel.  In the next image, you can see the finished product.

You’ll notice in the above photo that I chose not to include the rod that goes from the fulcrumed lever to the “A” truck.  This part ends up between the wheels of the truck and when the car is finished, and is not at all visible when the car sits right-side-up. This and the train air line are two things I omitted, but they could easily be included.  I chose to cut some corners at this step because I doubted how much these two details would contribute to the overall appearance of the finished car.

I’ll move on to the corner grab irons and some other wire details next time.

1 thought on “Ore Cars Step 15 – Mechanical Brake Parts

  1. I’m looking forward to seeing these on the layout!. Some of the few cars we can appreciate the break rigging at track level, as you suggest, especially in quantity. Very cool!

    Chris B

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