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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...



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!!! 
 

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Dwight!
That is some real fine work you have done there!  Bet you feel like you have learned a lot in this year.  My hat is off to ya.  Btw, are you going to make the change to the stack?
 

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Thanks Bob. Yes, I've certainly learned a lot this year. hehehe

The stack is one of those things still left to do. I'm not going to change what's already there, but I am going to turn an insert for the top. All of the later photos show it already removed, but I kinda like the look of it. :) Figure 2 must be an intermediate transition period. The spark arrestor is already gone and the whistle has been moved, but the headlight hasn't yet been raised up and there's no sand dome.
 

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Dwight,

Beautiful work on the air pump. And a fantastic job on the photography for a sise-by-side comparison with the prototype!

Best regards,

Alan
 

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Thanks Alan. :)

Charles - thanks for the link.  That's Tom Farin's #21 page.  He put that together from discussions on MLS when Bob Baxter and Chris Walas were building their sparkie versions a few years back.  It's been useful to me throughout this project.  Doesn't say anything about the air pump or its plumbing though. ;)

Part of the fun (to me) of this whole thing has been the research.  Same with my yet-to-be-started On30 layout based upon the SPC.  I enjoy learning about local history and how my area used to look.  It's fun to come across a street name like "Lick Mill Rd." and know where it came from. /DesktopModules/NTForums/themes/mls/emoticons/laugh.gif
 

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There's a device sitting atop the small air tank that for months I couldn't figure out what it was or what it looked like.  It was large enough and prominent enough that I wanted to reasonably represent it.



I finally sent out an email to a bunch of people I know and posted the same question and photos in the Public Forum (figuring I'd get the most views and responses there).  See this topic.
 
Only two people responded (including the emails) - Matthew and David Fletcher.  Both agreed it was a triple valve for the brake system on the tender.  David was also kind enough to email me this image of an 1883 triple valve...



Armed with this info, and not being able to find a commercial casting that would work, I set about to make one.

Taking proportions from the prototype photo, I determined that the overall height should be 0.656".  Measuring the above image of the triple valve, I generated an AutoCAD drawing from which I could take measurements.  The first step to making one was to rough out the shape from a piece of 0.375 brass hexagonal stock.  I turned the upper and lower cylinders manually, then clamped the part vertically in a machinist's vice on the milling table and wrote a little g-code program to mill the body profile and center-drill the hole locations.







After milling and drilling, I then had to use the lathe again to remove the scars left by the vice /DesktopModules/NTForums/themes/mls/emoticons/angry.gif (I did that after taking these photos 'cause I didn't notice them until I looked at the pictures).

I then started making and adding parts using various sizes of tube, rod, and wire.  Here's the finished triple valve...









Now to mount it and run the plumbing (I need more elbows again - sigh).
 

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Dwight,
your builder's log has two big disadvantages/DesktopModules/NTForums/themes/mls/emoticons/tongue2.gif:

#1 It makes everybody jealous of your excellent NPC #21
#2 Same holds for your CNC equipment!

By the way, I googled over the weekend and tried to find any patents by William(Bill) Thomas (designer of #21). Amazingly, none showed up... 
One more thing: Are you sure, the lower "steam collector" is really for steam. If you look at the backhead (or what would be a backhead on a conventional loco), you see a water gauge right at this spot. I think this is real, because the photos of the unfinished boiler don't show any fittings/holes for such a device at a different location.

Regards
 

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Posted By HMeinhold on 02/19/2008 8:30 AM
#2 Same holds for your CNC equipment!
Thanks Henner.  However, with the exception of the main body profile, everything here was done by hand.  :)

One more thing: Are you sure, the lower "steam collector" is really for steam. If you look at the backhead (or what would be a backhead on a conventional loco), you see a water gauge right at this spot. I think this is real, because the photos of the unfinished boiler don't show any fittings/holes for such a device at a different location.

I'm not 100% sure about anything on this locomotive.  Where did you see the site glass?  In a photo?
 

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More beautiful work Dwight, you are showing us all the way these models should be made  /DesktopModules/NTForums/themes/mls/emoticons/satisfied.gif
 

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Dwight,
the sight glass is visible in the drawing, spanning exactly the water level. On the photos of the boiler you can't see any fittings for either such a sight glass or try cocks. It would be mounted on the plate bolted  to the upper drum (which is still missing on the photos). I still think the drawing is quite authentic; it may even be from the (not yet found) patent drawings.
Regards
 
 

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That triple valve is a beautiful little part Dwight.  Can you make me one?  I want to wear it as a piece of jewelery.;)

Regards,

Eric
 

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Thanks Rod. :)

Henner - I have my doubts about drawings - first because I've seen a couple of them that were obviously wrong, and second because I doubt there were very many drawings made at the time she was built, and I doubt those survived.  If you're referring to the drawing I posted earlier from Those Amazing Cab Forwards, it was first published in 1983 - 81 years after #21 was built.  While I don't have the book and so haven't read it, I seriously doubt the author was an expert in obscure marine boilers.  The fact that the lower collector(?) connected to the globe valve out the back is, for all intents and purposes, identical to the upper collector(?) connected to the throttle valve, and yet is under water, indicates to me that the author was guessing at best.  The additional fact that the globe valve isn't shown connected to anything reinforces my suspicion that this drawing is wrong, as does my own study of the actual photos.

At any rate, when you come right down to it, without actual builder's drawings and with only a few grainy photos to go on, we're all guessing here, no matter how educated the guess may be.  :D  That being the case, if I can't see it and recognize it in an actual photo of the prototype, it's up for interpretation.  ;)

Eric - thanks, but no thanks.  /DesktopModules/NTForums/themes/mls/emoticons/tongue.gif
 

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Dwight, Your #21 is certainly looking FINE!!! Those little tiny pieces sure time consuming, I admire the amount of work you put in to them. I'm glad the Mason Bogie research and drawings were done for me or I would have never even gotten started. Looking forward to the finished loco.
 

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Thanks Winn. I enjoy the detailing on my models - always have (Tom Bowdler says I'm "anal" - hehehe).

I'm glad the Mason Bogie research and drawings were done for me or I would have never even gotten started.

And I'm equally glad I didn't have to make my own cylinders and valve gear or I never would have gotten started! ;) How's your Mason coming btw?
 

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Hope to have an update in a day or two. I'm finishing up the cab except for decals and windows. Trying to get all the parts for th RC servo links figured out. I'm getting down to the detailing which goes very slowly for me.
 

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I got the triple valve installed tonight.  There's one more pipe connection out the top, but unfortunately I'm out of elbows again. /DesktopModules/NTForums/themes/mls/emoticons/sad.gif 

Here are the requisite pics... /DesktopModules/NTForums/themes/mls/emoticons/tongue2.gif





and one from the same relative perspective as the prototype photo...

 
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