# Aster K4s arriving on track virtual one ;-)



## StackTalk (May 16, 2014)

When one buys an Aster via Ebay, there is always the wondering about what one will find in the box when one opens it up.

In this case, I got lucky, again.










I found one locomotive, one tender, one loose simulated (dummy) brake shoe, a spacer and a screw required to remount the loose item.

It did not look quite as pretty on its way out of the box as it does above, but I did send it to the "works" for a wash-up and a polish of the bright-work.

Has it been fired? What do _you_ think?













and . . .











It isn't perfect . . .

1 - There is a very small patch of green paint that has been rubbed off just in front of the cab roof.

2 - The cow-catcher was dinged a bit, but can easily be straightened and repainted.

3 - Wheel rotation is stiff. Before I even attempt to run it on air, the cylinders will need to be inspected and lubed up at the least. If it hasn't been run, it is not yet broken-in, despite being 30 years old.

In speaking with Jim Pitts today about my newest acquisition, he warned me that the marker lights and headlamp are brittle and can easily be broken, so it's especially nice that they arrived intact.

Also, the site glass is strictly for looks and operator deception; so watch the water level.

I will most likely play with it a bit on butane before I make the final decision to put it in the hands of Charles and Company for conversion. I am close enough to south Jersey to put it in the back of my truck and deliver it personally. 

Cheers,

Joe


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## StackTalk (May 16, 2014)

As I type this post, I do not know whether there are any replies above yet, so I will talk to myself just a little longer. 

My "shed" is not all that large. It consists of a Frank S (HF-110C,) an Aster Schools and a BR(WR) Castle, so I was pretty surprised by the relative size of the K4 when placed against the Castle:






















They are both 1:32 and the tractive effort of the real K4 is 44,460 lbf versus 31,635 lbf for the real Castle +/-, so the K4 was 40% more powerful as a prototype locomotive.

But here, the cubic volume of the K4 looks to be at least twice that of the Castle.

Here are the tenders:










So which one weighs the most?

The Castle [Edit: model] is heavier than the K4 by a fraction of a kg, whereas the Castle tender is about 1 kg heavier than that of the K4!

Looks are deceiving.

Cheers,

Joe


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## David Leech (Dec 9, 2008)

StackTalk said:


> Also, the site glass is strictly for looks and operator deception; so watch the water level.
> 
> 
> Cheers,
> ...


Joe,
I disagree!
The site glass is VERY important.
IF YOU SEE THE WATER LEVEL THEN PUMP LIKE ****.
It's just that it is too short!
Good luck,
Regards,
David Leech, Delta, Canada
p.s. That's interesting, I spelt out the word H*** and the system replaced it with the four ****.
I wonder what other words are treated as a 'no no'!


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## Semper Vaporo (Jan 2, 2008)

The following words are not allowed:

****
****
****
****
****
****
****
and 
****
and there might be others!


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## StackTalk (May 16, 2014)

David Leech said:


> Joe,
> I disagree!
> The site glass is VERY important.
> IF YOU SEE THE WATER LEVEL THEN PUMP LIKE ****.
> ...


 
Jim's point was that, in his experience, the K4 site glass is unreliable and works like h3ll. 

I would defer to him in the absence of information to the contrary. I find on the Castle, the site glass becomes useless in short order until one blows down and then it seems to be pretty good momentarily.

I reckon I will find out for myself by and by . . .

Butane fired locos are not forgiving if one runs low on water - or worse - whereas the meths fired locos tend to protect themselves a bit better from operator abuse. 

Cheers,

Joe


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## Kovacjr (Jan 2, 2008)

Joe, its not that the gas is less forgiving then meths but the original boiler that you still have in the K4 has a very large thin wall flue, that when low on water and if pumped with cold water will flash steam and collapse the boiler.


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## Kovacjr (Jan 2, 2008)

Semper Vaporo said:


> The following words are not allowed:
> 
> ****
> ****
> ...


And I though there were only 7 dirty words according to George Carlin


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## Semper Vaporo (Jan 2, 2008)

Variation in spelling and regional dialects create a few more.


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## Charles (Jan 2, 2008)

Joe
Our rule of thumb was to prime the engine via axle pump and/or keep the water at the top of the sight glass. As Jason indicated some K4's had a "thin" wall boiler and if it runs low on water could cause it collapse the flue (no all mainly relates to the first 50 out into production).
BTW- if you lose on the the classification(markerlights) we stock replacements.


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## StackTalk (May 16, 2014)

Kovacjr said:


> Joe, its not that the gas is less forgiving then meths but the original boiler that you still have in the K4 has a very large thin wall flue, that when low on water and if pumped with cold water will flash steam and collapse the boiler.


Jason,

Thanks.

[Edit: Didn't want to come across sounding like a know-it-all, lol.]

I understand the dynamics. In a meths fired loco, as the water level drops to the point where the boiler would be in the danger zone, the loss of steam removes the draft (either through the blast tube exhaust or the blower) which reduces the flame, thus providing some degree of self-protection from destroying the boiler.

With butane or butane/propane mix fired systems, one can keep supplying gas - and beaucoup heat - while the boiler runs dry.

This is what I am referring to . . .

So, as far as I am concerned, gas-fired systems are inherently inferior. 

If we add the pressure drop with cooled gas and the need to provide warming to the storage or supply tank with a steam return or water bath and we add the difficulties experienced in cold whether . . . and gas just does not "cut the mustard" in my opinion.

[Edit: I note that the K4 places the butane tank in the tender's water tank so there is that - better'n nuttin'  ]

We on the same page now, Jason?

If you know that the boiler in the K4 is _especially_ thin-walled or otherwise atypically more vulnerable, something I do not know, then that just make matters worse.

Cheers,

Joe


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## StackTalk (May 16, 2014)

Charles said:


> Joe
> Our rule of thumb was to prime the engine via axle pump and/or keep the water at the top of the sight glass. As Jason indicated some K4's had a "thin" wall boiler and if it runs low on water could cause it collapse the flue (no all mainly relates to the first 50 out into production).
> BTW- if you lose on the the classification(markerlights) we stock replacements.


Glad to know those classification lights are available. Maybe let Jim know you have them? You guys are on the ball for sure. 

Jim also had the same pointer for me: keep the sight glass full.

My S/N is 036/350, so mine is one of the early K4s.

I see an advantage here, though . . .

When I am done running the loco, instead of drying the boiler with air pressure before storing the loco, I can just reach in the cab and grab the boiler and squeeze the water out of it! 

Cheers,

Joe


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## StackTalk (May 16, 2014)

Kovacjr said:


> And I though there were only 7 dirty words according to George Carlin
> 
> http://www.youtube.com/watch?v=vbZhpf3sQxQ



Jason, I too am a fan of the late George Carlin.

I participated in a forum for many years that employed a funny word substitute filter.

If you wanted to say: "In a nutshell," it would come out "In a nutsheck." It was a WW II related site so every time folks discussed "shells" they were always "shecks."

If the offending word fell as a syllable within a commonly used word, the results could be quite amusing.

The filters ironically served to emphasize the words that they were supposed to suppress.

As an example, there was a fellow who posted often whose name was Hathcock. Whenever he signed with his own name, it came out "Hathchicken."

So discussion of a cockney accent became discussion of chickenney accent. 

One cannot make up this stuff.

Cheers,

Joe


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## Charles M (Jan 2, 2008)

Joe,
Not having seen an Aster K4 in the flesh, what is the circular opening below the valve handle in the 3rd picture ? Or am I not seeing an opening at all ? 

Charles M SA#74


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## rbednarik (Jan 2, 2008)

Charles M,

That is where the burner goes. Aster used a combustion chamber setup with a large diameter flue housing the single poker, held in place by a large brass plug which fits in that opening. 

A little history and information on the 80's US model Aster gas boilers, which only applies to the: NYC Hudson, K4, WM/GC&E Shay. 

There is a rear flue sheet about 1/2 way down the boiler with 3 smaller (approx 5/16") and one larger (approx 3/8") flue which extend until the smokebox end of the boiler (seen in the second photo in the first post). The large flues were made from too-thin diameter copper as stated and if subjected to any overheating and then suddenly (panicked operator) filled with water, the thermal shock would collapse it. 

Aster reissued the boilers with thicker walled large (combustion) flues, but the second weak point always remained in that the sight glass must always be full or else the large flue and 3/8" diameter smaller flue (plus the rear flue sheet brazing joint) are uncovered and can be easily overheated, causing collapse or failure of the brazing on the inner flue sheet. Especially the inner flue sheet, as this is constantly blasted with heat from the burner, unlike conventional straight flue poker setups where there is no impedance and gasses exit in the smokebox without directly touching a single boiler brazing joint. 

As long as the operator is mindful of his water, the boilers can last a very long time indeed. Razing the upper sight glass fitting is an option to give better peace of mind as the sight glass on the K4 is actually very good at giving true readings...just that the readings are bad for the boiler's service life. 

The passages in the sight glass/tubing are 1/8"-5/32" id and are well removed from the turbulence of the fire as they are to the outsides of the boiler water jacket. If only the upper fitting came off the top of the boiler, all would be perfectly OK, that would allow you to run with 3/4 glass and be safe. 

I believe David Leech has a photo of just such a modification to a Hudson boiler using the original fittings and bushings.


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## David Leech (Dec 9, 2008)

rbednarik said:


> I believe David Leech has a photo of just such a modification to a Hudson boiler using the original fittings and bushings.


Yes, I do!
As you can see it raises the observed water level to well about the burner flue.
Regards,
David Leech, Delta, Canada


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## StackTalk (May 16, 2014)

Here is the poker burner:











I have taken a series of "before I do anything" photos.

So the sight glass works, but is poorly sited. 

David, your modification looks to be a good way to show the full range of water levels.

Ryan, thank you for all of the background information specific to the K4 boiler and your input generally.

I plan on firing the K4 in the next week or two and running it on the rolling road, but most likely it will not see a track in its present configuration. 

I'll have a care to avoid damaging the boiler by keeping the level up, but I won't worry overly much if damage should occur as it is likely that I have one of the very early boilers and as Charles knows, I am seriously considering a conversion. One way or the other, the boiler is likely to be replaced.

I have found the source of most of the binding/rolling resistance, but I will save that for another time as I am off to work.

Cheers,

Joe


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## Pete Thornton (Jan 2, 2008)

> I was pretty surprised by the relative size of the K4 when placed against the Castle:


 Just as an aside to this conversation about thin flues and dirty words . . . 

Britain built a lot of railways before it was discovered that bigger trains wouldn't fall over on corners. Having built with stone, it was tough to rework all the railways for the standard 'continental' (and US) loading gauge. Hence UK trains are generally smaller - as you can see from the photo.

Another recent issue, now that there is a Chunnel, is that continental freight trains can't venture off the Chunnel high-speed tracks. There's one exception - the GWR from Paddington was built to Broad Gauge and the bridges and tunnels easily accommodate big trains. Unfortunately, it's a long way from the Chunnel to Paddington!


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## StackTalk (May 16, 2014)

Pete,

Thank you. 

I often find the background information just as interesting - and sometimes even more interesting - than the "foreground" information . . . as to why things are the way they are.

Oftentimes, we see photographs of one thing or another without there being an obvious point of reference in the scene to judge size. If there are photographs of UK outline locos positioned alongside US outline locos, I have not seen them as yet. I suppose such would only take place at a railway museum somewhere.

Funny enough, I had always thought of my Frank S as "toy-like" in appearance until one day I began looking at pictures of various other prototype Henschel HF-110C locomotives and it was then I understood that the real things were toy-like in appearance as well, owing to the narrow gauge proportions.

After I unpacked the K4 and placed it beside the Castle, I went over to Jim's Southern Steam site and looked up the dimensions for other U.S. outline models, Mikado, Berkshire, among others, to gain a better understanding of relative size. I then began to look up the various tractive effort numbers for the prototypes so that I could see what size had to do with power.

From the reading I have done about the UK "big four," I see that a good deal of consideration had to be given to the curve or turn radii and to the loading that the track and roadbed could handle. I assume our engineers needed to address such issues as well, but to date, most of the little reading I have done concerns things UK.

I just ordered up three books relative to the PRR as an adjunct to having purchased the K4. If I do not learn something every day, what's the point of going one? 

I imagine you have read about the French ordering up some new kit that won't make it through 1/3 of their stations?

Ouch! That has to hurt.

Cheers,

Joe


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## Kovacjr (Jan 2, 2008)

StackTalk said:


> Jason,
> 
> Thanks.
> 
> ...


 
Just keep in mind that a Meths boiler makes steam until there is no water left way past the danger zone. 

From the boiler image in the first posts if does look like the thin wall one. Never know there may be a newer updated boiler available from someone that converted to meths of coal.


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## David Leech (Dec 9, 2008)

Joe,
Before I converted my NYC Hudson to alcohol, I found it very difficult to get the gas burner to light.
How I used to do it in the end was to pull it out slightly to light from the cab end, and then using the suction fan pushed it back in, which seemed to get the fire going nicely, and then removed the suction fan.
Maybe the K4 is better!
I'm sure that you will let us know.
All the best,
David


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## StackTalk (May 16, 2014)

Kovacjr said:


> Just keep in mind that a Meths boiler makes steam until there is no water left way past the danger zone.


Good to know, Jason. A word of caution here is not misplaced.

I think my cavalier-sounding approach may be somewhat influenced by the 1975 Aster Schools which has no sight glass and no pressure gauge. One simply metes out the required number of CCs of water and alcohol, lights the thing off - and off it goes until it either runs out of alcohol or water and stops on its own. I suppose it is designed to run out of fuel before running out of water?

Cool it off; wash, rinse, repeat.

Perhaps this laissez faire approach explains why some of these old model locomotives with smithies boilers, are nicely browned-off on the sides! 

My Schools looks new, and so far, I have been able to keep it looking that way.



> From the boiler image in the first posts if does look like the thin wall one. Never know there may be a newer updated boiler available from someone that converted to meths of coal.


 I have made a few impulsive purchases lately. (Who does not do so from time to time?)

If, upon reflection, I decide I am going to hang on to the K4 for a while, I will invest further in it, most likely asking TRS to do a conversion for me. Time will tell.

Changing gears . . .

I realize I was a little hard on gas-firing in my earlier post.

If this were a model boat discussion group, rather than a train-related group, most of the boiler-related discussions would be about gas-fired boilers with the occasional evaporative alcohol burners such as is employed by Saito and Aster being commented upon. One can't very well use a chicken-feeder wicks-based alcohol fuel approach on a model boat, which tends to bob around unless one likes to film spectacular small fires on the waterfront. 

That said, there is something to appreciate about not having to warm the supply tank to try and get enough liquid butane into one's "day-tank," and then to try and keep the fuel temperature low on the loco fuel tank so as to coax out as much run time as possible without having to worry about the ambient air temperature so much.

That - and the fact that there is no connection between water level, steam pressure and burner temperature, unless one uses a regulator of some sort such as the products of Forest Classics or Anton.

http://www.forest-classics.co.uk/bix029.htm

http://jmc.vapeur.free.fr/index.htm

As long as I keep topping up the water, I get from 65 minutes to 75 minutes of run time from the Castle. It would be hard to get that kind of run time out of a gas-fired loco, wouldn't it?

Must get back to work . . .

Cheers,

Joe


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## Charles (Jan 2, 2008)

Joe
Speaking of steam boat and the Saito system, are aware that there has been several applications of the evaporizing burner system on steam locomotives!



StackTalk said:


> Good to know, Jason. A word of caution here is not misplaced.
> 
> I think my cavalier-sounding approach may be somewhat influenced by the 1975 Aster Schools which has no sight glass and no pressure gauge. One simply metes out the required number of CCs of water and alcohol, lights the thing off - and off it goes until it either runs out of alcohol or water and stops on its own. I suppose it is designed to run out of fuel before running out of water?
> 
> ...


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## StackTalk (May 16, 2014)

Did I mention that I have to get back to work?

. . . So that I can leave early today and meet my sister and brother-in-law for dinner and a concert. 

No, Charles, I was not aware of evaporative alcohol burner systems being used in model locomotives, but why would anyone want to listen to all that racket interfering with the lovely stack talk? 

For those who haven't used one, think ramjet engine. 

I Googled while eating lunch here at my desk and up to four pages and no examples found yet.

But I bet you have copious photos . . .

Cheers,

Joe

PS: I have a T2DR, a T3DR and a T2GR with Saito brass boilers (I know brass is a very bad word when used alongside boiler, especially if one is British.  )

The early Aster two and three cylinder marine engines similar to the Saitos are not made as well, btw. 

Arrrrgh, Blasphemy!


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## Steve Ciambrone (Feb 25, 2014)

It looks like the K4 is just a poorly designed boiler and burner, I would think a redesigned boiler with a simple flue or even two flues and burners would work well. As far as gas fired locos, most of us just turn them down to quiet them and conserve fuel and water for longer runs. The Saito burners once started and warmed up should be dialed down to reduce the noise and extend the duration. I have also converted a Saito boiler to gas fired with a ceramic burner and it is very quiet.
It is all fun.
Thanks
Steve


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## Pete Thornton (Jan 2, 2008)

> If there are photographs of UK outline locos positioned alongside US outline locos, I have not seen them as yet. I suppose such would only take place at a railway museum somewhere.


 Back in 1969 the LNER "Flying Scotsman" came and toured the US. I assume there are more photos around of it alongside a US loco, but this is the only one I found:


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## StackTalk (May 16, 2014)

Pete, I wonder whether anyone can identify the US locomotive alongside the A3?

It does not look like one of our larger US steam locos, but a great photo just the same.

Cheers,

Joe


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## iceclimber (Aug 8, 2010)

Is it a Mikado? Sort of looks like it from the front to me anyway.


Congrats on the acquisition of my most coveted engine. The K4.


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## David Leech (Dec 9, 2008)

Savannah & Georgia 4-6-2 number 750.
All the best,
David Leech, Delta, Canada


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## StackTalk (May 16, 2014)

So . . . .

I mentioned that the K4 came into my possession with three issues (now four, counting the boiler issue,) identified where work needed to be completed.

The slight rub-off of the green paint just in front of the maroon cab roof will be taken care of in the future when I can figure out how and where to source the paint.

These days, one can go to a paint store and have an item color-sampled and matched nicely for water-based paints including enamels. I suppose there are specially auto paint places that can do the same?

Advice welcomed.

The cow-catcher came in damaged and looked like this:












And gradually, using what I call my 30 cent solution to bending the brass . . . 













I ended up with this, which, though not perfect, will do:












Now on to the binding problem, next post.

Cheers,

Joe


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## StackTalk (May 16, 2014)

David Leech said:


> Savannah & Georgia 4-6-2 number 750.
> All the best,
> David Leech, Delta, Canada


 Thanks for that, David.

What I was wondering about is how the locomotive in the photo compares with the K4.

Relatively speaking, a K4 is larger than a light Mikado, but smaller than a Berkshire or a GN S2, for example.

In the photograph, the US locomotive does not seem so much larger than the A3 as I would have expected, so this led me to suppose that the US outline loco was a smaller main line loco than a K4, for example?

Cheers,

Joe


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## StackTalk (May 16, 2014)

I have been thinking about starting a thread revolving around my recent Aster Castle build. I do realize the Castle is a 2009 loco kit (with a few BR(WR) liveried kits remaining for purchase,) so not the latest thing and probably not a lot of interest? Hopefully such a thread would not come across as a vanity thread. 

My purpose would be to encourage anyone who was on the fence to give it a go, while at the same time I would describe a few knuckle-headed things I did that, through discussion, may keep others from repeating. At the same time, I would definitely learn some things from the more experienced.

Topics would include such things as:

So you think you passed the "runs well on air test," so why doesn't it run on steam?

How is it that you put the upper banjo bolt on the lower side of the axle pump while putting the lower banjo bolt on the upper side even though you are one of the world's greatest interpreters of mechanical drawings?

Thread-locker? Who said anything about using thread-locker and what kind should we use or avoid?

Lubrication, where, how and why?

How not to make mistakes even though one believes one has very good reading comprehension skills and therefore it is the manufacturer who must have made a mistake? 

OK, you are going to make mistakes anyway, but can we please reduce the number of them?

"I read all of the advice there is on the Interweb - all the experienced builder's logs - and still I goofed?" How is that possible? 

* * * * *

Anyway, what does any of the above have to do with the K4?

I had the K4 running on air (accidentally) the other evening, but I do know, based on my experience that it would be a waste of time trying to steam it up because it will not run in its "as is" condition.

How can I be so sure?

Because my recently arrived at rule of thumb is that, if you can push the loco across a table (covered with, say an Alvin self-healing cutting pad,) or down a test track and the wheels don't turn on their own, don't waste your time trying to steam it.

IMHO, the weight of the loco itself should always provide sufficient downward pressure to cause the wheels to turn.

The K4 is stiff and I know why.

So how did I get it to run on air by accident?

I filled the Roscoe oiler with semi-light weight machine oil and pressurized it with air so that I could back-feed some lubrication into the cylinders and the darn thing ran on its own. No blow-by, by the way.

But it took 30 to 40 PSI for it to run and it should run on as little as 5 to 10 PSI, so we have some loosening up to go.

The machine oil did result in an improvement, but oiling will not "fix" what's wrong.

With the K4, here is what the linkages look like:

(Keep in mind the loco is inverted. I suppose I could invert the photograph, but why do that?)












OK, so in order to determine where the resistance was originating, I separately uncoupled the main driver rod(s) and the D-valve rod linkages to "feel" the individual levels of resistance.

The valve rods seem fine, but the pistons took quite a bit of hand pressure to move back and forth even after I forced lubricant into the cylinders and lubed the slides.

Turns out that the next photo tells the story:












The resistance to sliding on the slide clamping mechanism is the issue.

No doubt, Aster used thread-locker on those two small screws, but once I loosened them, the slides would do what they were supposed to do - they slide. So while I can feel some of the effects of compression, there is most likely nothing wrong inside the cylinders.

I reckon I am going to have to lap the slides because as it stands now, the slides are not slides so much as they are clamps.

I am "off" for the weekend, so no new info until later in the following week.

Cheers,

Joe


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## StackTalk (May 16, 2014)

Thanks to David's lead, found some information on the Savannah & Atlanta #750 light Pacific - 4-6-2

http://www.railarchive.net/randomsteam/sa750.htm

S&A 4-6-2 #750

Tractive effort = 31,000 lbf
Weight, 180,000 lbs.

The Gresley A3

Tractive effort 32,910 lbf
Weight, 205,000 lbs

So the two locos in the picture were comparable. I suppose over here, a Gresley A3 would be classified a light Pacific.

Cheers,

Joe


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## BigRedOne (Dec 13, 2012)

Joe,

I'm sure plenty of people would enjoy such a thread, especially those interested in the model or contemplating building a steamer. I know I've enjoyed all the steam threads.


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## StackTalk (May 16, 2014)

Last time I posted a progress report on readying the K4 for running, I had identified the crosshead slides as the primary source of chassis rolling resistance.

As it turns out, by removing the two screws that bolt the crosshead to a brass slide that fits into a "T" shaped slot, the motion of the pistons overall is much improved. In fact, as a temporary measure, I ran the loco slowly in either direction on the rolling road with 12 PSI of air. Give it 20 PSI to 2 bar, and it runs quite nicely at speed.












In the image above, one sees the newly polished reverser control mechanism and handle on the left and the unmodified crosshead slides on the right along with the brass slides that fit inside the "T."

Below is a shot of the disassembled loco.












The paint and detail work is very clean overall with only the area identified as having paint damage and when I can find matching paint, the piece itself comes off, and the repair will be an easy one.

Next week I'll finish up the work around the cylinders and decide how much "clean-up" I want to do to the patina of the various driver and connecting rods. I like the way it looks naturally aged, so I may leave it as you see it? Not sure.

But I should be able to fire it up next week or the following week depending on life's other distractions and whether I find the paint to fix the one area while the loco is in pieces.

Cheers,

Joe


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## Charles (Jan 2, 2008)

Joe
Cross head guides might be an alignment issue when put in place or needing a bit of filing for smooth motion of the crosshead.


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## StackTalk (May 16, 2014)

Charles said:


> Joe
> Cross head guides might be an alignment issue when put in place or needing a bit of filing for smooth motion of the crosshead.


Charles,

Thanks. I did not go into any detail above, but yes, the guides were "out of plane," a bit. It is easy to make such a determination once one uncouples the crosshead from the slide and allows the crosshead to move freely in its "natural" plane. One than can observe the angular difference or diversion from a parallel plane.

Mainly though, with the screws that fasten the crosshead to the brass slides in the "T" tight - as they were "factory tight," the brass slide was pulled up snuggly against the lower edge of the "T" in such as way as it became a clamping mechanism.

I was able to square the motion easily enough, but now I will lap the edge of the guide that contacts the crosshead itself. After removing, say .002 at time, I will get to the point where the screws can be tight, the motion is fluid, but not sloppy.

For the above operation, I tape first 1000 grit and then 2000 grit wet-or-dry to a precision plate, which as you know is a heavy stone guaranteed to be flat to within .0005.

I use a bit of cutting oil on the stone when I do this.

Cheers,

Joe


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## StackTalk (May 16, 2014)

*U.S. Gasketmaking . . .*

Moving along a little at a time . . .

I was able to remove the pistons without having to take the cylinders off the frame, so time saved there.

As discussed, the cross sides were binding on each side because the "keeper" or brass slide piece was binding against the inside of the "T" within the slide. The "T" shape I have been referring to can be seen in the image on the left, looking at the slide from one end.













For some reason, one slide was 0.198 in. and the other side was .193. I polished up one side down to .189 and it worked a treat as I was able to reassemble the entire side and test that motion was smooth and only piston compression could be felt.

New gaskets being made here:











Brass tube at left is the home-made punch for the holes.

That was the good news.

The bad news is that, in attempting to assemble the opposite piston into the cylinder, the piston would bind internally no matter what I did. It even binds when held "free" as in no end-cap in place.

Piston diameter is 0.511 in.
Rulon piston ring diameter is 0.511 in.

I did not mike the "good" side, but the other side was smooth as silk and I suspect the ring diameter > the piston diameter as well it should have been.

I am guessing that the rings on the one side dried up and shrunk.

I have contacted Hans about getting two sets of rings, so we will have a bit of delay putting things back together.

Cheers,

Joe


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## Charles (Jan 2, 2008)

Joe
Seems that the K4 was fortunate to be in capable hands and you will be enjoying a run in the near future. Might I suggest while you have it apart to hone the cylinders and lap the surfaces. How are the link and rods as to tolerances/loose?


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## StackTalk (May 16, 2014)

Charles said:


> Joe
> Seems that the K4 was fortunate to be in capable hands and you will be enjoying a run in the near future. Might I suggest while you have it apart to hone the cylinders and lap the surfaces. How are the link and rods as to tolerances/loose?


Charles,

Thank you, again.

How do you recommend honing the cylinders? I don't have a hone that small. Perhaps you can recommend one?

Keeping in mind my limited experience with these little engines, the linkages feel about right to me, neither sloppy nor tight. I have rolled the loco around on the table-top with "one lung" only and the motion is fluid.

I am lapping the cylinder covers, but if I can get away without having the valve chests open, I may do so, hoping that I do not regret having taken the short-cut later. 

When I ran it on air in both directions, there seemed to be no blow-by and it went as well in reverse as forward. The one cylinder (piston) being stiff now has me a bit puzzled, though new rings and honing should take care of the issue.

Regards,

Joe


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## StackTalk (May 16, 2014)

Looks like items of interest here:

http://www.americanlap.com/Barrel%20Laps.htm


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## StackTalk (May 16, 2014)

*Inching my way toward Altoona ;-)*

So . . .

I decided it was not necessary to locate a hone for the cylinders as they are nice and shiny and varnish-free inside.

But . . .

While I am waiting for a set of replacement Rulon piston rings to arrive, there was some work to do.












In the image above, one can see the lateral scoring of the piston which results from the diameter of the brass piston (.511) being no smaller than the diameter of the Rulon piston ring, also .511.

No wonder the left cylinder was binding!

I am not sure whether the Rulon ring experienced shrinkage over the years or whether someone ran the loco extensively on air without lubrication, but there is an easy fix in any case.

Let's slightly reduce the diameter of the brass piston, shall we?

I do have a lathe and could have turned down the piston if I were able to successfully separate the piston rod from the crosshead without scoring it, but it was easier to oil up a strip of 2000 grit wet-or-dry and simply rotate the piston by hand. Even if the surfaces were rounded at the ends a bit, it would not matter so long as I did nothing to adversely affect the grooves which hold the rings.

Here is the result:












and












I soaked the original rings in light oil for two days and temporarily reinstalled them and assembled the cylinder without sealant . . . and the motion is smooth and the compression appears to be good.

I could probably get away with keeping the original ring set.

Not having the new rings has effectively prevented me from putting things together, so in the meantime, a little disassembly and re-painting of detail items was in order.

Below, I renewed the builder's plate(s)












Cheers,

Joe


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## JEFF RUNGE (Jan 2, 2008)

In my 17 years in this hobby building over 30 Aster engines, I have never need to, or ever heard of anyone needing to turn down a piston... not sure that was a wise move.


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## StackTalk (May 16, 2014)

JEFF RUNGE said:


> In my 17 years in this hobby building over 30 Aster engines, I have never need to, or ever heard of anyone needing to turn down a piston... not sure that was a wise move.


Jeff . . .

I wouldn't think removing a maximum of .003 really constitutes significant "turning down."

The scoring caused by the original piston fit should be visible in the photos above . . . and as I have reported, the binding was significant.

Bear in mind that the axles would not turn on this loco under its own weight originally and all of the binding was in the two cross-slides and the left cylinder.

It took 30 PSI just to get it moving initially, 40 PSI to get it to appear to move at scale speed on the rolling road.

The original Aster dimensions on the crosshead slides were asymmetrical in thickness by at least .005 as I described within this thread, so Aster isn't perfect. 

[Edit: One side was .193 the other .198. They are both now .189 and the slide on the right side (assembled) is very smooth.

Finally, this loco has never been fired since it was originally (factory) assembled and if it ran at all, it would have been on air only a . . . and probably not with proper lubrication.

* * * * *

The new Rulon rings came in from Hans later today and before leaving for the weekend, I test fit them. Piston itself .508 to .509. Ring diameter mounted, .510 to .511.

I lubed up the rings and cylinder walls and the fit is still tighter than on the right side, but there is no more metal on metal feel to the motion as I had before polishing the piston.

I did not permanently reassemble the left-side cylinder assembly yet, but I feel confident that I will be able to roll the chassis without binding and I am hoping to get it to run on air (briefly,) with about 10 PSI.

I have left the new rings soaking in oil over the weekend and will see whether I can reassemble it next week, failing that, by the week following.

After reassembling the left side cylinder assembly, I will take the right side apart again to replace the original piston rings and while apart, just for jollies, I will check the diameter of the right-side piston.

Thanks for your input.

Anyone following this thread will find out how the story ends, whether in tears or in joy. 

Cheers,

Joe


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## JEFF RUNGE (Jan 2, 2008)

Sorry, I did not see where you measured the cylinder bore, this would be the ONLY way to determine if you had the correct piston to cylinder clearance? I guess you could remove the rings and see what it felt like, they should be pretty snug( not sloppy) but stll slide freely. If the rings are sitting below the piston surface, you can slide them over a tapered drift and run them under hot water to expand them a little, but they will should seal just fine when the steam gets behind them and forces them out against the cylinder wall.


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## StackTalk (May 16, 2014)

Jeff,

What is the diameter of a piston? Where is it measured? What should be the clearance between piston diameter and cylinder bore?

Allow me answer one of these questions on my own, before I refer to others who may know more than Jeff or I.

The piston diameter that really counts is the diameter of the piston + ring. If one takes a little "meat" off the piston without affecting the diameter at the ring, one can adjust for poor overall clearance, overall piston diameter to cylinder bore safely, I would think. But let's not rely only on my opinion.

This post may be regarded as an informational _bridge_ post, a bridge between doing a bit of research and reporting it here for the benefit of those reading along, and my next K4 work session which will be this evening. I have two evenings scheduled for this week and I will continue on next week.

*Dave Stick . . .*

Sorry to name-drop.  In the most recent issue of G1MRA NL&J, Dave discusses his rebuilding of his own King George V, originally built by him circa 1990. Dave has probably built as many Asters as Jeff. This fellow does a number of things I cannot even conceive of doing, one of which is to run a model locomotive often enough - and long enough - to wear it out, literally. I can assure everyone that I will never wear out a live steam model loco because I'll never have the opportunity, nor find the time, nor have the passion to do so.

What does Dave do when he wears out a loco? He rebuilds it, of course, and in this case, Dave put in quite a lot of work, including over-boring the original 11 mm cylinders to 7/16", sleeving them with K&S brass stock 7/16" O.D. and then turning four new pistons using the "Dick Abbott tried and true magic formula."

Re-reading Dave's article got me to thinking that I ought to be ashamed of myself if I went as far as tearing open the K4, but stopped short of opening up the steam chests and re-lapping the D-valves and mating surfaces even though I suspected to do so is unnecessary in this case. 

I have mentioned more than once now that this early K4 has never been steamed, but apparently it has been run on air (probably dry, by some person not aware of the need for lubrication,) long enough to score the piston surfaces. And if the piston surfaces are scored, what of the D-valves and mating surface?

One of the methods Dave uses to confirm a good piston to cylinder fit is to simply put his fingers over the steam ports and push-pull the piston to make sure there is plenty of resistance indicating little to no leakage past the rings.

So I will end up putting in a couple of extra evenings before I put the K4 back together. I needed to remind myself why I am doing this in the first place . . . and what was that reason again?

Was it to have an opportunity to be needled by Jeff Runge? No. I don't think that was part of the plan. 

Oh, I remember now: it was to have a bit of fun?

* * *

So what is this *Dick Abbott magic formula *for piston, o-ring and cylinder bore relationships?

Ordinarily, one has to be a G1MRA member to read the wonderful NL&J, but it just so happens that the free sample (August 2012) contains the Dick Abbott article:

http://www.g1mra.com/pdf/autumn-2012-newsletter.pdf

I don't want to ramble on all morning, but here is the upshot where it may pertain to my K4 rebuild.

The piston diameter - sans o-ring, should be about .010 smaller than the cylinder bore.

In my view, without the rings present, this is indeed a "sloppy fit."

I certainly can feel 10 thousands and while I have not measured the bore on the left cylinder as yet, I can assure the dear reader of this thread that the clearance was nowhere near 10 thou.

A couple of blown-up views of the piston with the original rings:






















Even allowing for the fact that, compared with brass (gun metal to any Brits present,) the Rulon rings are soft, the K4 left cylinder had "zero" protrusion of the ring diameter above the cylinder diameter and the scoring certainly makes this pretty clear. In the pictures above, it even appears as if the rings have receded below the level of the piston diameter.

Now why did I not measure the bore before pronouncing the need to either increase the bore or decrease the piston diameter?

Laziness did play some small role, but also, I did not have any small inside calipers handy at the location where I am doing this work. (My machine shop is in Oceanside, NY and my build location is near my workplace on Staten Island.) More importantly, the binding was felt to be so severe, that to measure was a mere formality.

How would I know how to _feel_ binding without using an inside micrometer caliper? 

It may have something to do with having had one semester of foundry, one semester of Industrial Processes and a class in metallurgy. More to the point: six semesters of machine shop and one semester of inspection shop in my early background and a life-long love of things mechanical. Oh, and having access to my own genuinely modest machine shop.

[Edit: But a part of the purpose of this thread has been to encourage other folks not to fear to take their locos apart and work on them, even without a strong background. To build an Aster loco, or to "clean one up," a machine shop is not required.]

Should the Rulon piston rings protrude above the diameter of the brass piston itself, while cold and obviously not under steam? Yes, they should.

If the answer were "no," then woe unto anyone who ever runs a model loco under air because 0.000 clearance would mean a lot of unnecessary wear before ever getting to use the loco for its intended purpose.

One can deduce what the clearance ought to be in reading Dick Abbott's article.

So far, I have reduced the original piston size from nominal .511 diameter to a nominal .508 or a total reduction in diameter of .003 without reducing the portion of the piston diameter that supports the Rulon rings. The net effect is to allow the Rulon rings to remain at nominal .511 overall, a mere .0015 nominal protrusion. (.003 of diameter implies .0015 or radius.)

Why did I start throwing in the word "nominal" in the above measurements?

Because the best tools we generally have available with which to measure are only accurate to +/- .001, if that, in the first place - and errors in measurement may be additive (and can be subtractive as well.) If one starts with a measuring tool that has an accuracy of +/- .001, one is undoubtedly likely to add human measurement or handling error to the above by another +/- .001 or more. Some may introduce more error than others according to experience, but even the most talented among us will introduce some measurement error.

It is easier to measure a small outside diameter (piston) accurately than it is to accurately measure a relatively tiny inside diameter (boring.)

But as I say, there is nothing like .010 of clearance between the naked brass piston and the boring of the cylinder in my K4, left-side.

If one has the slightest interest in relationships between piston, o-ring and cylinder size, take the time to read the Dick Abbott article.

To be continued . . .

Cheers,

Joe


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## StackTalk (May 16, 2014)

By the by . . .

I am aware that this thread has had some 1,766 views as I type this, and no more than 1,700 of them can be accounted for by my reviewing what I previously typed. 

So as long as there is some interest I will carry on.

I do not mind a little good-natured needling now and then as well. 

Jeff's input is responsible for my re-reading Dave Stick's Aster King rebuild article - which then prompted me to read Dick Abbott's piece and to then refer it to the readers of this thread.

And now I _think_ I know what proper piston, ring and cylinder clearances should be.

So . . . "it is all good." as they say.

I hope to continue to learn a few things . . . whether I actually like it or not. 

And I hope others are encouraged to tear things open and have some fun putting them back together as well.

Cheers,

Joe


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## JEFF RUNGE (Jan 2, 2008)

Joe, Are you applying O ring theory to a Rulon piston ring application ? It's your engine so do what you want, but you seem willing to do a lot of research. May I suggest you read up on piston rings? Also the material "Rulon" which unlike many piston rings, will have little too no "spring tension" , but relay on pressure from behind the ring to seal like other piston rings. 
Good luck
Jeff


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## JEFF RUNGE (Jan 2, 2008)

What have I learned? I've wasted my time trying to point you in the right direction. Good luck with your project.


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## StackTalk (May 16, 2014)

JEFF RUNGE said:


> Joe, Are you applying O ring theory to a Rulon piston ring application ? It's your engine so do what you want, but you seem willing to do a lot of research. May I suggest you read up on piston rings? Also the material "Rulon" which unlike many piston rings, will have little too no "spring tension" , but relay on pressure from behind the ring to seal like other piston rings.
> Good luck
> Jeff


Jeff,

I don't need any luck at the moment. A little _real_ or helpful input perhaps, would be welcomed, as opposed to pseudo information, but thank you for your wishes for continued good luck, just the same.

* * *

You have caught me taking a short break in this evening's work session, so I will add a bit of information first and then comment briefly on your posts in this thread, thus far.

I decided to re-assemble the cylinder with the .003 lapped and polished piston and give it the "Dave Stick push-pull suction test." The fit is smooth; the motion is now fluid, and with the steam passages blocked, there is ample compression with the piston "rubber-banding" to center whether pushed or pulled.

I am satisfied all is well concerning the clearance piston-to-cylinder bore for this cylinder even if Jeff Runge has his un-quantified doubts. 

I have just run the loco on air, (heavily lubricated in the steam passages,) and disconnected one main driver rod at a time, running the loco first on one cylinder and then on the opposite cylinder to see whether one cylinder moves the wheels better than the other. I observed no discernible difference. I am using just under 10 PSI and I am getting scale mid-speed - not too fast but not too slow either. I will try and put up a video at some point.

This engine will run very well under steam.

I started the process of opening one of the steam chests, but I am vacillating a bit now and leaning toward leaving them alone based upon my estimate of the additional time required versus possible gain. I will think on it some more, but I can't imagine much of an improvement considering I have it running in both directions - one direction at a time, of course,  The loco runs slightly better in forward, but it runs fine in reverse.

Jeff . . .

Don't you think that my words speak for themselves? I have been accused of a few things in my life, but being inarticulate has not been one of them.  

I am not applying "o-ring theory" to the Rulon ring fitment. What can be said is that I am applying the _practice_ of estimating the clearance between the brass piston host for the ring and the diameter of the cylinder bore. It seems to me that .010 of clearance suggested by Dick Abbott (for O-rings) is what I would have expected. But if I were supremely confident that .010 is what is needed, I would have to take off another .005 or so. I like to study things, but I am also a pragmatist. Because I am now satisfied that the .003 I have removed is doing the job nicely, I am content to leave it where it is.

You have stated that the piston to cylinder bore clearance is important, on this we agree, but you have volunteered _no useful information whatsoever_ as to what it ought to be? I find your contribution to this thread to be decidedly unhelpful thus far, Jeff.

I find myself asking: "Where are you coming from?" And "If you are unwilling or incapable of being truly helpful, are you willing to go back?"

How about some references? How about suggesting how the clearance for o-rings differs from those of Rulan piston rings? Let us have a pleasant and useful dialog. Why not share your superior knowledge and experience with the rest of us poor souls?

That said. I did in fact go to the Saint-Gobain site earlier today and did some reading. Have you? And if so, what have you learned, Jeff?

One thing I learned is that there are probably more than 20 varieties of Rulon with unique characteristics each.

Jeff, may I respectfully suggest that you either participate affirmatively in this thread or that you keep your oblique criticism and your wishes of good luck to yourself?

Thank you!

Cheers,

Joe


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## StackTalk (May 16, 2014)

Jeff,

What you reacted to above was an accidental post. The one immediately preceding this post is what I meant to say.

Cheers,

Joe


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## JEFF RUNGE (Jan 2, 2008)

Fair enough. A little very basic piston compression ring theory. ( we will keep this about compression rings not oil control rings) The metal rings used in internal combustion engines and steam engines are sized a little larger then the intended bore they are used in. However most of the sealing power is provided by gas pressure ( on in our engines steam pressure ) that gets behind the ring and forces it out. In an internal combustion engines this only takes place in one direction, so some manufacturers modify one side of the ring to aid in this process. Because our engines are double acting cylinders the ring are just square cut. The direction of travel loads the ring to one side of the grove allowing steam to get behind the ring and push it out against the cylinder wall. ( this is why it was not important that your rings did not stick out past the piston surface) 
The material Rulon material used to make our rings have no useful outward pressure. You can expand them up by sliding them over piston body and running them under hot water, but this is only a temporary effect. 
For this reason the fit of the ring into the ring grove is very important in order to prevent the ring from twisting. The ring ends being cut at an angle gives a bit of flexibility in the final bore diameter. (Sealed power used to make a ring with a stepped end cut to do this) Most rings have square cut ends and are gapped based on bore and operating temp.
Ok thats all for tonight.


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## iceclimber (Aug 8, 2010)

Good info Jeff.


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## StackTalk (May 16, 2014)

JEFF RUNGE said:


> Fair enough. A little very basic piston compression ring theory. ( we will keep this about compression rings not oil control rings) The metal rings used in internal combustion engines and steam engines are sized a little larger then the intended bore they are used in. However most of the sealing power is provided by gas pressure ( on in our engines steam pressure ) that gets behind the ring and forces it out. In an internal combustion engines this only takes place in one direction, so some manufacturers modify one side of the ring to aid in this process. Because our engines are double acting cylinders the ring are just square cut. The direction of travel loads the ring to one side of the grove allowing steam to get behind the ring and push it out against the cylinder wall. ( this is why it was not important that your rings did not stick out past the piston surface)
> The material Rulon material used to make our rings have no useful outward pressure. You can expand them up by sliding them over piston body and running them under hot water, but this is only a temporary effect.
> For this reason the fit of the ring into the ring grove is very important in order to prevent the ring from twisting. The ring ends being cut at an angle gives a bit of flexibility in the final bore diameter. (Sealed power used to make a ring with a stepped end cut to do this) Most rings have square cut ends and are gapped based on bore and operating temp.
> Ok thats all for tonight.


Jeff, Thank you, I would characterize the above post as a helpful and well-meaning post. 

I can better appreciate that the clearance above the piston diameter suggested by Dick Abbott for o-rings - is not applicable to the Rulon piston rings - and why not.

I have replaced pistons and rings on small internal combustion engines as well as a couple of auto engines and I have rebuilt a number of air compressors over the years, but have not had need until now for the information you have provided for Rulon piston rings. Thanks again.

With respect to the K4, what I believe that I have accomplished despite not understanding that Rulon ring clearance may not be a concern above the piston diameter, is that I improved the interference piston-to-cylinder bore without harming the fit of the Rulon piston rings - or so my preliminary testing would indicate. This assertion is subject to confirmation when steaming up the loco.

Perhaps I have experienced some "good luck" after all.

I'd be curious whether you agree that .010 is the correct clearance piston diameter-to-cylinder bore or whether some other clearance is recommended for Rulon ring equipped pistons.

Finally, it would seem, based upon the information you have provided that it really is a good idea to avoid running any steam engine equipped with Rulon piston rings on air for any length of time as they cannot possibly swell and perform on air as intended and metal-on metal contact piston to cylinder bore is a likely result.

Perhaps you can pick up on this another time.

Thanks again.

Cheers,

Joe


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## StackTalk (May 16, 2014)

Alrighty then . . .

*Time for a SUMMARY . . .*

I purchased an Aster K4 via Ebay which was purported to be in pristine condition and unsteamed.

Upon receipt, it was determined definitely to be unsteamed and received in the original wooden crate with a few items needing attention, including a couple of small cosmetic blemishes that were easy to repair.

However; The chassis was very stiff and also in need of attention.

As it turns out, there were three areas of binding or friction that contributed to the loco not moving under air . . . unless 30 to 40 PSI was supplied.

The main binding points were these:

Both crosshead slides were binding with insufficient clearance between the crosshead and the "keeper" or rectangular slide within the "T" shaped slide/support. Geometry was checked. One side was determined to be .198 and the other to be .193 in top to bottom "thickness" and these were reduced to .189 and polished on the precision stone.

The above took care of about 50% of the binding. The remainder of the chassis rolling resistance was determined to be located in what was identified as the left side (actually the right side) piston-to-cylinder bore clearance.

A (somewhat) controversial polishing of the offending piston removed .003 from the outer diameter and resulted in a smooth fit and no loss in compression. 

New Rulon rings were applied and Jeff Runge provided us with some good information as to how Rulon rings work in a double-acting steam engine and how they differ from conventional piston rings.

Below is the interim result:








Cheers,

Joe


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## StackTalk (May 16, 2014)

Closing in on 2,000 views for this thread, so I feel I ought to point out two things about the video that have been suggested to me privately before everyone who is going to watch it, watches it and moves on . . .

I do not show the oiling of the chassis and cylinders and it looks like the chassis may be running dry. What I did do was put quite a lot of light-weight machine oil in the feed pipe before attaching the air line and then I ran it a bit with a rag over the blast pipe to sop up the excess oil ahead of making the video.

I do not like running these locos on air at all, actually, but I did do bit more running on air than I would like for the sake of this thread.

The second thing goes to absent-mindedness I suppose . . .

I was heavy-handed about the way I shifted rapidly from forward and reverse and back. Got a little too carried away, did I. 

The motion should be slow as if one is shifting a car.

Otherwise . . .

There will be a lull for a bit while I figure out what I wish to do next.

Cheers,

Joe


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## StackTalk (May 16, 2014)

*She now runs on air @ 5 PSI !*

Greetings!

The K4 chassis was languishing a bit as I moved on to other things.

Maureen and I took a four day weekend on Cape Cod and during the visit, attended a steam-up in Brewster. As it was my first steam-up, I was too focused on watching and getting my Castle ready to run to take many photos.

I did get the Castle running and pulling a rake of seven BR Mk I chocolate and cream coaches, but alas, I had had only about 10 minutes of running at moderate speed before a problem developed.

The issue turned out to be quite minor and I will save the discussion for another time.

Oh . . .

And I left with a BR-9F "Evening Star" kit in the back of my Tahoe. 

* * * * * *

Back to the K4 . . .

When last I posted, Charles PM'ed me and asked whether I was going to check the valve timing before reassembly. Never pays to take shortcuts.

I popped off the steam chest covers and found the right side timing to be as near-perfect as I could get it, but the left side eccentric needed a bit of twist counter-clockwise (anti-clockwise to you Brits,) so as to allow the steam ports to be more exposed. They were only opening a slit and they were not balanced (front versus rear) as to degree of opening and this required moving the d-valve positioning a bit.

So Some results . . .










It is a pleasure to set outside valve mechanisms when compared with setting inside mechanisms.

With the reverser centered, one should have the d-valve approximately centered (while the eccentric lobes on the drivers are straight down.)

Rocking the reverser back and forth should open the front and rear steam ports about the same amount +/-

In the above shot, I am checking the forward setting on the right side. The reverser is forward; the piston is front dead center and the rear steam port should be exposed.










Other side above . . .

In neutral, neither port should be open:











After setting, we (the K4 and I, ) needed some new gaskets and a polish to the steam chest covers:











And she is now ready for reassembly after the Holiday . . .












Five PSI . . .

After lubing everything up, the chassis moved along briskly in forward and reverse @ only 5 PSI.

To be continued . . .

Cheers,

Joe


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## StackTalk (May 16, 2014)

*Good News; bad news and good news again . . .*

As of last evening, the K4 was back together except that I have left the cab off until I finish up testing under steam.

The good news is that the loco runs quite nicely under steam in both directions on the rolling road.

I only ran it for about five minutes for two reasons:

I had a gas leak.
Once running, I remembered that the last time I filled the lubricator was not with steam oil, but with machine oil!

So I shut'r down before taking any videos this time.

A couple of issues cropped up . . .

I previously spent no time on the tender, and when steaming the engine for the first time ever in thirty years, I discovered that it has an easy to repair water leak - more of a slow drip.

Also, one of the hoses that is supposed to have a fitting on it had none and the hose that was supposed not to have a fitting on it had one. This is a head-scratcher for a factory assembled K4, but easy to remedy.

The other thing I noticed was that gas was leaking from the gas c0ck on the burner. See below:










Looking at the top picture, hopefully you will observe that the packing gland nut on the valve is too tall for the valve assembly, right?

Yes, there is a silicone 0-ring under the nut, but it is only half as high as the space reserved for it and so the valve leaks, but also . . .

The stem is not tall enough to seat the valve properly and so it does not close completely either.

If I close the valve with the packing nut missing, the valve still passes some gas (and it doesn't even say "Excuse me!  )

So . . .

There are three such valves on the K4, one for the gas reservoir (tank,) one for the bypass valve and one for the valve on the burner. No, they have not accidentally been switched around or substituted.

I have no way of explaining this mystery, however; I am going to shave the height of the nut so the nut just pinches the o-ring and then the valve will close 95%.

I like the idea that the valve only closes 95%. Why so?

Because, when I lit the burner with the valve closed tight (at 95%) and with the valve on the tank open, there was just enough gas-flow to light the burner with a small pop and for it to act as a pilot light until the valve was opened to a full flame. Lighting the burner on the first go was incredibly easy.

Next week I will run the loco for the length of a full tank of gas and water to check the total run-time and I will put up a video here.

Cheers,

Joe

PS: I was able to purchase a J&M PRR "Edgar Allan Poe" heavy last night on Ebay (now sitting in Germany,) so I have started in a very small way to put a rake together.


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## BigRedOne (Dec 13, 2012)

Looking forward to seeing it run!


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## StackTalk (May 16, 2014)

Thank you!

Me too 

Tomorrow after _real_ work I will repair the water leak on the tender and the gas valve on the burner. The gas leak was from the stem, but also from the threads so I will want to seal the threads and let the assembly dry overnight.

I expect to test the K4 on the rolling road on Wednesday evening and I will take some video clips at the time.

Cheers,

Joe


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## StackTalk (May 16, 2014)

So now I am now stoked, pumped and chuffed, 


I ran two sessions on the rolling road tonight, the first one being a bit funny and the second one as good as I would hope, but the storage disk in my old Canon camera ran out of space near the beginning of the second session so I did not get a lot of the "good" session on video.

The first session was funny because I was "skeered" of my own locomotive. 

During my air tests, I had noticed that the safety valves never opened even when I put enough pressure in the boiler to peg the gauge.

Before steaming, I removed the valves and soaked them in acetone then blew them out, lubed them up and made sure that they had good opening mechanically.

During the first session tonight, when the steam gauge pegged at full scale (which I thought was 6 bar owing to me vision slipping with age, but was really only 5 bar,) I panicked and shut off the gas flow twice and then relighted the burner while the loco was running. At one point, because half of you scared me concerning the early boiler and the risk of blowing it out, I overfilled the boiler twice and then took a shower as wet water mist finally blew out the relief valves due to over-charging the boiler. 'Twas funny to watch, of that I am sure.

Once I decided "screw it, let's see when the valves open," they began to open at 5 bar and close at 4.5 bar.

I did get some of my over-reaction on video, lol. 

The first run was about 45 minutes.

For the second run, I made a point of squeezing in as much butane as possible.

The second run started at 10:12 PM New York time and the gas ran out at 11:14 PM so a good run on the rolling road.

The K4 did not have much stack talk running free, until I used my finger on the center driver to add plenty of friction and then opened up the regulator and then she chuffed. 

I realize that a loco has to run well on the rolling road before one can believe it will run well on the track, but until it is on the track, one does not know for sure.

However;

I am now confident that the K4r will have good pull.

I will try and put up a video here in the next day or two.

Cheers,

Joe


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## StackTalk (May 16, 2014)

So . . .

The K4 is about 95% back together and I have now had about three hours with it running on the rolling road. 

I am satisfied that it will run well on the track, but, as I do not yet have a track of my own set up, it may be a while before anyone sees it in the context of a train of Penny heavyweights at work.

Here is the video I promised, more or less:










I did take about two hours of video. But to have to watch that much would be incredibly tiring for anyone - a bit like a home movie, but without the excitement of watching Little Billy jump off the diving board and into the pool - while holding his nose and flailing his arms!

What you see above is less than 15 minutes and even then, I doubt anyone will watch it completely.

What you will get a glimpse of is this:

The K4 is incredibly easy to light and to keep lit.
The gas may have to be adjusted at least once and maybe twice in a one-hour period - mostly as the gas pressure drops near the end (not shown)
The loco runs very smoothly slowly in either direction and can race like a thoroughbred.
I talk too much. 

Cheers,

Joe

[Edit] The first minute or two is slightly fuzzy until I remember to turn on the macro feature of the lens and then the quality is sharp. You'll also see how quickly the K4 clears its throat.


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## StackTalk (May 16, 2014)

*Had a breakthrpough and Charles was right!*

A quick update before retiring for the evening . . .

The thing that has been stopping me from finishing the assembly of the K4 has been the inability to find paint to do a bit of touch-up work.

I do have a 30 year-old tin of paint that came with the loco, but upon opening it up, the paint was black and dried flat upon application and drying, so no joy.

Charles recommended going to an auto body shop and having someone mix the paint to match a cylinder cover, but I was loathe to take that approach. In passing, Charles mentioned that Aster used a shade of green that was a bit too green when compared with the prototype. I had done research prior and I knew he was right, but stumbling into a dark shop on a side-street with no sign on the door confirmed what we now all know:










Well there it is in black and white, Aster K4 green is named "Inauthentic Green."

I was able to buy it in the brush on version and the pre-thinned air brush version. Wow!

So, after repairing my new air brush, here is a glimpse of how the paint matched up:










The little square above the Belpaire fire box is the newly painted piece. In any kind of lighting I have tried, I can't see the difference with the naked eye.

More next week.

Cheers,

Joe


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