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.

Ore Cars Step 14 – Air Brake Equipment and Piping

Having already built one pilot model, I knew that this step was going to take a while.  Three major components of the air brake system are represented on the model.  These are the triple valve, the brake cylinder, and the air reservoir.  Each of these components is assembled from two or three very small resin parts.  I have to question the wisdom of designing the kit this way.

I suppose that casting these parts in resin was likely done to keep the cost of the kit down.  On close inspection, these parts look blobby and vague when compared to the quality of injection moulded styrene detail parts.  If I was only building a relatively small fleet for a home layout, say fifteen cars or less, I might opt to buy styrene parts.  In fact, I had to substitute some Details Associates and Cal Scale parts on one ore car because some of the small brake parts had come loose from the resin sheet and were lost at some point in the distant past.

Our club has to eventually roster fifty of these cars, so building these fifteen ore cars with injection moulded styrene parts with more detail than the other thirty five doesn’t make much sense.  Nor does it make sense to improve the detail on all fifty cars, despite the much simplified assembly that injection moulded parts would afford.  I guess I’m whining a bit because it took so long to build parts that are passable in a large fleet, but don’t provide stellar detail.  I’ll get on with it now.

The three components are: cylinder, reservoir, and triple-valve.  The brake cylinder is comprised of three parts: the body, a cone on the end where the shaft comes out, and a dish on the opposite end.  The reservoir has four parts: two halves of the tank, and two L brackets to secure it to the frame of the car.  The triple-valve is cast in two parts: one that comprises about 3/4 of the part, and curiously, a tiny piece that gets glued onto one end.  When comparing the part to photos of the prototype, the triple valve looks more accurate without the addition of the little bit on the end.  As in most instances when I’ve been confronted with opportunities to make the car more accurate, I built the car the with the parts provided in order to simplify construction and make the fleet  fifty cars consistent.  Around a dozen of these cars were built at some point in the past, and I won’t be building the remaining unbuilt kits at our club, so that’s a something that I needed to consider when making a decision at a moment like this.

Before the nine parts for these three components could be removed from the resin sheet and cleaned of flash, I drilled #76 holes to anchor the air pipes that would be added later.  The triple valve got three holes on the side facing inward, the reservoir got two holes on the side facing inward, and the brake cylinder got one hole in the end that looks like a dish.  There are dimples to guide the bit in the reservoir.  The holes in the back of the cylinder and the triple valve go where they seem most appropriate.  After they were all drilled, I removed them from their sheets, cleaned off the flash, sorted them into piles, and assembled each component in turn.

After the tedious process of assembling the components, I glued one of each to all fifteen cars.  That step in the sequence went more quickly.

There is probably an easier way to measure and bend the piping that goes between these components, but I approached it in a way that was easiest for me, given the tools and materials I prefer to use.  I don’t have details of the actual routing of any of these pipes, but I think that what I came up with is a suitable representation of a network of air brake lines, based on drawings I have of other types of cars.

There are three pieces of air pipe that I built from .015″ brass wire: two that go between the reservoir and the triple valve, and one between the triple valve and the brake cylinder.  The prototype car has more piping than this, but in keeping with the underlying goal of building this fleet cars like a terracotta army, I settled on representing these three important air lines.

I built one master for each pipe by trial and error.  When I was satisfied that I had come up with something that was workable, I wrote down the dimensions of the sections between the bends.  I unfolded the wire to measure its straight length and then chopped up fifteen similar pieces.

The first pipe that I built is the shorter of two pipes between the triple valve and the reservoir.  Through trial and error, I determined that I wanted to build a z-shaped pipe with right angles.  The overall length of that pipe is .800 inches.

I used a grab iron bending tool that is marked in thousandths of an inch to bend all of the pipes the same way.  I made the first bend .350″ from the end.  I made the next bend .450″ along from the first one.

I had to adjust the fit of the pipe to each individual car.  There is some variation in the location of the three brake components on each car because there are no guide pins to locate the parts precisely, and there are limits to the precision of my skills to located them in a “freehand” way.

After I’d installed this first pipe to each car, I repeated the process for the pipe that runs more-or-less beside this one.  This second pipe measured exactly 1 inch long overall.  The first bend was done at .250″ and the second bend was done at .450″ from the previous bend. I made fifteen duplicate parts this way.  Again, this pipe fit a bit differently on each car, but starting with the basic part already bent saved a great deal of time.

The third pipe goes from the flat side of the brake cylinder to the triple valve.  This pipe is so short that it was a simple matter of cutting it from scraps left over from making the masters of the first two pipes.

In the next step, I’ll install the moving parts that include the clevis and the various rods and levers that transfer the movement of the brake wheel and the brake cylinder to the brake shoes on the trucks.

Ore Cars Step 13 – Steps and Ladders

In the previous instalment of this series, I added exterior details above the floor line at both ends of the cars. In this step, I added ladders and stirrups.

The process consisted of trimming the Tichy parts to length – four rungs on the end and five rungs on the sides. The side ladders have a short bracket holding the ladder to the car body because it hangs out over the end.  The kit includes a tiny 2″x4″ piece of resin of the exact length for this purpose.  To save time, I opted to glue all of the side ladders to a strip of 2×4 styrene.  When the CA had dried, I chopped them off the strip and glued them to the car body.

This slideshow requires JavaScript.

After the ladders, I glued the stirrups in place.  They are also Tichy parts, and they need to be trimmed off of their sprues.   At this point, I noticed that I had missed drilling out some of the holes.  I had to spend a bit of time finishing that step to about five cars, and then I glued the stirrups into the holes.

In the next step, I’ll assemble reservoir and bracket assembly, plus the brake cylinders and the triple valves.

Ore Cars step 12 – end details above the floor line

The last time I posted about the CPR drop-bottom ore cars, I’d built up the brackets for the triple valve from three small pieces.  For this post, I’ll show the work required to put a variety of details onto each end of the cars.

There are basically four parts that go onto the A-end of each car: a platform, a grab iron, and two levers.  In addition to the brake wheel, all of these same parts also go on the B-end of the car.  I don’t have a photo to illustrate the ends of the prototype cars the way they appeared in the 1970s.  At some point after the end of the ’70s, these hoppers had their drop bottom doors welded shut when a rotary dumping facility was built at Inco.  Prior to that, and during the time I’m modelling, the cars were unloaded by workers operating a pair of levers that opened the floor.  I’ll start by explaining how the levers went together.

I used a drafting divider, with the points set to 18 scale inches, to mark the holes that need to be drilled for the grab irons. You can see that I kept all four levers together on the resin sheet. This made the parts easier to mark and drill.

After the levers were marked, I used a #80 drill bit in a pin-vise to drill out two holes in each lever. Two holes per lever, four levers per car, fifteen cars, that’s 120 holes.  I wonder how many holes it takes to fill the Albert Hall.

Once the levers were drilled, I inserted an 18″ straight grab iron into each one.  With all four levers still together, I ran some thin CA across the back of the parts to adhere the grab irons to the levers.  The levers on the left are finished, the levers on the right are next in line.

With the grab irons attached, I shot the back of the resin sheet with accelerator an nipped the extra wire off.  The levers were trimmed from the resin sheet and stored them in my parts container.

Next, I drilled a #76 hole into the brake housing casting to accept the post on the back of the brake wheel.  I assembled all 15 of those and stored them in my parts container.  I also cut 15 bits of wire left over from the rods that operate the doors in the floor.  This will be used to represent the chain coming out of the bottom of the brake wheel housing.

Having previously drilled for all of the grab irons, gluing went quickly.  I glued the levers, walkway, grab-iron, on the A-end, then the same parts plus the brake wheel/chain assembly on the B-end.  Here’s the result:

Levers, walkway, grab-iron, brake wheel and housing – that’s it for step 12.

The cars are getting closer to being ready to paint.  I’m predicting four or five major steps in the construction sequence before that point.

Ore Cars Step 11 – Progressing toward the really small bits

Having finished putting the end cap plates onto the sides of all the cars, the carbodies are now pretty much together.  From here on, I’ll be adding grab irons, levers, air brake components, and the associated piping.

At this point in the assembly, most of the parts have been cut off of the resin sheet holding all the parts together.  The sheet for each car was fragmented into small bits, and many parts were beginning to just fall off of some of the thinner sheets.  It was getting difficult to keep track of those small parts, so I took some time to go through all of the kits and collect all of these small parts together in one place.  It took about an hour, but I’m feeling better about having the parts sorted and in one place.

Moving back to the assembly of the cars, I decided to work on the triple valve mounting bracket.  The triple valve is mounted to the large plate that is cantilevered out away from the centre sill in the photo below.

That plate needs a bracket holding it in place and that bracket is in two parts in the kit.  The first part sits vertically between the end of the plate and the cross bearer above it,  or beneath it in photo below, because the car laying upside down.

Above, you can see that the vertical piece is a bit too big.  I glued that piece onto each car, and then went back to the first car to trim the extra material down with a sanding strip.  The photo below shows the result.

The second piece of the bracket lays on the cross bearer butted against the vertical piece.  The next photo shows it more clearly.