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Continuing the Builder's Log now in the archives here.
Today is an appropriate day for an update since it was one year ago today that I bought my CNC milling machine and started this project.
I've been putting off installing the air pump for several reasons. One, I was looking for an appropriate casting in both style and size. Second, I was still agonizing over how the damn thing was connected. Third, I knew what a tedious PITA making up all the pipes would be. /DesktopModules/NTForums/themes/mls/emoticons/sick.gif
I picked up a few pumps from Trackside Details a little while back. The most promising was their TD-9X (which was actually the first pump I bought). I wasn't real thrilled with it due to the (imho) poor quality of the casting. After receiving the others (TD-190, 191, and 192), while the castings were better quality, the size and/or style was all wrong. I also got a Bachmann pump off their 4-4-0 from TOC (thanks Dave), but ultimately wasn't real happy with it either.
On a whim, I ordered another TD-9X. This one was far better in quality - the first one must have been a fluke. With the pump settled upon, it was time to modify it.
Here's the original casting...
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While the second one was a lot smoother and cleaner, the center section between the cylinder and compressor was still filled with... well, I'm not sure what to call it. The first step was to mill out the center section. I also drilled a hole up through the bottom for a simulated connecting rod made from 1/16" piano wire which I shined up. While I was at it, I cut the governor off the TD-190 air pump, drilled it for 0.06 brass wire, and silver soldered it to the 9X, and started fabbing the air line. I then made an H-bracket to mount it.
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As I said, I've agonized over how this thing was hooked up for many months now. I've gathered opinions from many people, including David Fletcher. The problem is the lack of clear photos, so much is left to educated guesswork. The steam input line and the exhaust were the problem. In the following photo, which I'll call Figure 1...
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it would make sense to assume that the exhaust would be the pipe running into the smokebox. After long study, I came to the conclusion that such was not the case. The pipe coming from the smokebox goes through a glove valve, then some sort of large hex-shaped union, and then appears to go into an elbow and head north. This shows even more clearly in this photo, which I'll call Figure 2...
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The exhaust seems to head down behind the air line, but deep shadows make it unclear where it actually ends (see (3) in Figure 1). This last photo finally convinced me with reference to the exhaust line...
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The cloud of steam right near the center of the air pump leads me to believe it ends here. Consequently, that's where I chose to end mine, as shown here...
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On to the steam supply line where similar problems are faced due to a lack of good photos and information. Figures 1 and 2 were my only real sources of info here. Referring to Figure 1, the shadow under the handrail (2) made it appear to me that the steam line ran above it, probably to the cab. However, even more careful scrutiny exposed the little bit of light just to the right of the handrail stanchion (1). Could it come from the globe valve on the rear of the weird steam collection cylinder atop the boiler? I can also see what might be part of an elbow on the bottom of the globe valve.
I had as a reference this drawing from Those Amazing Cab Forwards...
![]()
This drawing originally convinced me that the globe valve ran back down into the boiler, though I had no idea why or what purpose it would serve. Ultimately, I decided this drawing is probably wrong (like so much info about this loco). If you look closely at the thing inside the cylinder the globe valve is connected to, it looks just like the steam collector connected to the throttle. I concluded that the water probably didn't get up that high, and that both were most likely steam collectors, which left the lower one free to supply the air pump. While it meant I'd have to change what I'd already done, I decided to connect the air pump steam supply line to this globe valve.
Figures 1 and 2 ultimately led me to conclude that the steam supply line comes off the cylinder globe valve, runs aft horizontally above the handrail, then down on the left side of the pump, through a tee, then aft through a second globe valve and into the smoke box. I'm not sure why it's connected to the smokebox, but after months of staring at these photos, it' the only thing that seems to fit what I see.
Here are the completed pump and steam supply line...
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and the two fit together...
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and here they are mounted to the boiler...
![]()
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The air line runs back to the end of the running board, through a connector, and into a hose...
![]()
which in turn runs through another connector and into the large air tank on the tender...
![]()
Finally, on the 1-year anniversary of this project, I thought it would be fun to take a couple comparison photos from the same camera angle as my primary prototype photo.
The prototype...
![]()
The Model...
![]()
![]()
Still more things to do before she's ready for paint, but she's getting real close!!!
![]()
Today is an appropriate day for an update since it was one year ago today that I bought my CNC milling machine and started this project.
I've been putting off installing the air pump for several reasons. One, I was looking for an appropriate casting in both style and size. Second, I was still agonizing over how the damn thing was connected. Third, I knew what a tedious PITA making up all the pipes would be. /DesktopModules/NTForums/themes/mls/emoticons/sick.gif
I picked up a few pumps from Trackside Details a little while back. The most promising was their TD-9X (which was actually the first pump I bought). I wasn't real thrilled with it due to the (imho) poor quality of the casting. After receiving the others (TD-190, 191, and 192), while the castings were better quality, the size and/or style was all wrong. I also got a Bachmann pump off their 4-4-0 from TOC (thanks Dave), but ultimately wasn't real happy with it either.
On a whim, I ordered another TD-9X. This one was far better in quality - the first one must have been a fluke. With the pump settled upon, it was time to modify it.
Here's the original casting...
While the second one was a lot smoother and cleaner, the center section between the cylinder and compressor was still filled with... well, I'm not sure what to call it. The first step was to mill out the center section. I also drilled a hole up through the bottom for a simulated connecting rod made from 1/16" piano wire which I shined up. While I was at it, I cut the governor off the TD-190 air pump, drilled it for 0.06 brass wire, and silver soldered it to the 9X, and started fabbing the air line. I then made an H-bracket to mount it.
As I said, I've agonized over how this thing was hooked up for many months now. I've gathered opinions from many people, including David Fletcher. The problem is the lack of clear photos, so much is left to educated guesswork. The steam input line and the exhaust were the problem. In the following photo, which I'll call Figure 1...
it would make sense to assume that the exhaust would be the pipe running into the smokebox. After long study, I came to the conclusion that such was not the case. The pipe coming from the smokebox goes through a glove valve, then some sort of large hex-shaped union, and then appears to go into an elbow and head north. This shows even more clearly in this photo, which I'll call Figure 2...
The exhaust seems to head down behind the air line, but deep shadows make it unclear where it actually ends (see (3) in Figure 1). This last photo finally convinced me with reference to the exhaust line...
The cloud of steam right near the center of the air pump leads me to believe it ends here. Consequently, that's where I chose to end mine, as shown here...
On to the steam supply line where similar problems are faced due to a lack of good photos and information. Figures 1 and 2 were my only real sources of info here. Referring to Figure 1, the shadow under the handrail (2) made it appear to me that the steam line ran above it, probably to the cab. However, even more careful scrutiny exposed the little bit of light just to the right of the handrail stanchion (1). Could it come from the globe valve on the rear of the weird steam collection cylinder atop the boiler? I can also see what might be part of an elbow on the bottom of the globe valve.
I had as a reference this drawing from Those Amazing Cab Forwards...
This drawing originally convinced me that the globe valve ran back down into the boiler, though I had no idea why or what purpose it would serve. Ultimately, I decided this drawing is probably wrong (like so much info about this loco). If you look closely at the thing inside the cylinder the globe valve is connected to, it looks just like the steam collector connected to the throttle. I concluded that the water probably didn't get up that high, and that both were most likely steam collectors, which left the lower one free to supply the air pump. While it meant I'd have to change what I'd already done, I decided to connect the air pump steam supply line to this globe valve.
Figures 1 and 2 ultimately led me to conclude that the steam supply line comes off the cylinder globe valve, runs aft horizontally above the handrail, then down on the left side of the pump, through a tee, then aft through a second globe valve and into the smoke box. I'm not sure why it's connected to the smokebox, but after months of staring at these photos, it' the only thing that seems to fit what I see.
Here are the completed pump and steam supply line...
and the two fit together...
and here they are mounted to the boiler...
The air line runs back to the end of the running board, through a connector, and into a hose...
which in turn runs through another connector and into the large air tank on the tender...
Finally, on the 1-year anniversary of this project, I thought it would be fun to take a couple comparison photos from the same camera angle as my primary prototype photo.
The prototype...
The Model...
Still more things to do before she's ready for paint, but she's getting real close!!!
