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Discussion Starter · #22 · (Edited)
In an early post, you said Swiss adhesion/rack engine. Does that mean this engine is capable of running on non-rack sections in between rack rail sections?
Ive been to Mt. Washington Cog RR and Pikes Peak Cog RR, and they both have racks installed on every inch of track.
I was wondering how the engine proceeded from non-rack rail onto the rack rail and get the gear in alignment with the rack?
They had (and still have today) a very sophisticated system to synchronize the gears when entering the rack section. First a hinged section at the beginning of the rack was set on springs in case the gear happened to sit on top of a tooth. Secondly the pitch of this section was slightly different from the pitch of the gear. This ensures that after a couple of feet the gear synchronized with the rack. Also sometimes the height of the teeth varies. Many Swiss rack systems today switch between adhesion and rack at fairly high speed using this method. See e.g. https://www.google.de/search?q=zahnstangeneinfahrt&source=lnms&tbm=isch&sa=X&ved=0ahUKEwih8KOGxc7gAhUPVK0KHVb3CR4Q_AUIDigB&biw=1536&bih=701&dpr=1.25.
The prototype of my loco ran without rack within the iron works and entered the rack section when climbing up a hill.
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Discussion Starter · #23 ·
The boiler fittings (manifold/throttle/safety valve/dead-leg lubricator/water gauge) are done. It was pointed out to me (I should have known better), that the water gauge should not be tapped off the manifold, as opening the throttle will affect the reading. I will proceed with the remaining plumbing and then test the loco under steam. If the gauge really misreads, I will solder a separate bushing into the boiler. Yesterday we milled the reach rod out of 1/16" steel. Here how the loco looks like now:



The throttle handle is some black rosewood, donated by Dennis.
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You don't have much room to work with! I guess you could turn off the throttle to read the gauge. I never have much luck reading site gauges on the run anyway. Good luck.
 

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I saw a Ruby with a sight glass fitted like yours. It would not run at all due to water being drawn off the bottom of the boiler through the sight glass and through the throttle valve. The cylinders would never clear.
Good luck, beautiful build so far.
Keep 'em Steamin'
John
 

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The water glass my be a problem, maybe not...i am curious about how you are running the throttle...do you have some more photos showing that detail?
 

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Discussion Starter · #27 · (Edited)
Eric,
the throttle was a bit of a headache. In the real loco it is housed in the dome. I could not do that, as there is absolutely no space on the front end for a lubricator. So I put the throttle into the manifold, having to use a fairly long steam line (the Ruby has about the same length, so I might be OK). Here is a picture of the throttle proper (the M4 thread is not shown):





and the temporary routing of the steam lines:




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Very interesting project Henner...thank you for sharing your progress.

A small suggestion...you may want to consider insulating the steam line running from the manifold forward to the split "T" over the front of the boiler...The plastic tubing you have used would be an excellent insulator...even if you need to split it to get it to fit.

Alternatively if you can do a few bends and run the steam line from the manifold through the firetube you can do a great job of keeping the steam hot and avoid condensation....I hesitate to call it a superheater line, but it would act somewhat as one.

Otherwise, with no insulation you'll have a lot of heat loss in that copper tube between the manifold and the front.
 

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Discussion Starter · #29 ·
Cliff,
In the Ruby the steam line runs from the throttle via two bends through the lubricator and then uninsulated under the boiler to the fairly bulky reverser valve with a lot of surface. The line is longer and has more surface area than my pipe system. The Ruby design seems to work OK. Obviously the heat transfer between the fast moving steam and the wall of the pipe is not outrageously high. But I will definitely insulate the long pipe, as the prototype tube had a fairly large diameter. However I will first test the temporary piping to see, what happens.
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Wow that is really neat! Good job on the throttle too, i couldnt qquite figure it o u t from the earlier photo..
 

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Henner
Maybe we could fill the boiler to the top of the sight glass and then run it on air and see what is going on with the clear tubing. Start, stop, etc.
 

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Discussion Starter · #32 · (Edited)
The live steam piping is done. I had to go around the water filler valve on the dome. Dennis and I had two competing designs for this manifold, but Dennis' "won". It is a ring channel which will also minimize heat losses, as it is in contact with the dome. Everything is silver brazed, quite a tricky job, as the wall thickness of the brass donut is just 0.02".




The next steps are the exhaust piping and adding RC. I decided on radio control, as this loco is not of the - fire up/let it run for 30min/watch it sitting in a lawn chair with a beer - variety. In fact it will run fairly short distances with frequent reversal.
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Discussion Starter · #35 · (Edited)
The functional part of the loco is done and I have run some tests.

- Burner/boiler generate enough steam to hold 30PSi.
- Frame and servos get lukewarm at best.
- The rulon slide valves seem to work well.
- Due to the short connection between jet holder and tank the gas tank gets just enough heat to keep the pressure.
- The fairly long steam line does not seem to be a problem, even without insulation.
- The dead leg lubricator also seems to work.
- So far the complicated valve gear has not shred itself to pieces :).
- The location of the sight glass was indeed a problem as it worked as an ejector pump. I soldered a separate bushing into the boiler and shortened the manifold.


Yesterday, after successfully running on rollers, I built a test track in my garden. The rack (cog) railway branches out of the main line with a portable switch and climbs directly up the hill, bypassing a line with two switch backs, which had to be abandoned due to termite damage on one of the bridges. The new track was simply laid on top of the old line:



Here the loco in its natural habitat. The tender contains the RC equipment and was used for this test only. Eventually the RC will go into the cab:



Finally a short video of the test run (my friend Dennis was the engineer at the throttle):




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Henner
It runs beautifully and the drive mechanism is mesmerizing.
You seem to have mastered the complex Gooch valve system for a smooth and powerful engine
Congrats.
 

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Discussion Starter · #39 ·
As the loco seems to run, I can focus now on "detailing". The smokestack is one important feature of a loco, so I focused on that first. I made 2 attempts making the saddle, but was not happy with either. Dennis (Bill's and my CNC/laser guru) came up with a brilliant idea. The saddle was turned in one piece with an integrated skirt 0.02" thick at 30° degrees. This was annealed and then formed to match the boiler curvature. Here is the result:





Here the loco with the finished smokestack:





The cab is temporary and laser cut out of thin MDF. It is a mock-up to check the installation of the R/C components, as the loco is very small. The smokebox door was turned using coordinates and the hinges made in a fixture. If someone is interested, I can describe how I did it. Currently I am waiting for various hardware and R/C components.
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