"Chicken" update

[Jan-Eric Nystrom]

In another topic, the question of wear on Teflon valves was mantioned.

Well, here's an update to the article about the "Chicken" (in the latest two issues of LS&ORR):

I decided it was time to take apart the "666" after two summers of running. Who knows how much wear there might be in the bearings, or in the valves and cylinders - after all, they are made of copper-nickel, a material much softer than bronze. Furthermore, the engine had become quite dirty, as you can see...

http://www.saunalahti.fi/~animato/3003/PICT2116.JPG
When I removed the cylinder assemblies, I was rather shocked at the amount of crud that had accumulated behind the crossheads!

http://www.saunalahti.fi/~animato/3003/PICT2133.JPG

Well, time to disassemble everything, and do some cleanup work! I started by taking off the rods, and had a look at the teflon/bronze/steel bearing bushings...

http://www.saunalahti.fi/~animato/3003/PICT2155.JPG

Nice! No wear at all, the bearings look just like they did when I installed them, almost exactly two years ago.

Now, it was time to open up the cylinders...

http://www.saunalahti.fi/~animato/3003/PICT2141.JPG

Again, a nice surprise! Having run at least 800 kilometers (500 miles) since the engine was built, the cylinders still had some of the honing marks left! The Viton O-rings on the pistons were also in good shape, in fact so good, that I did not see any need to exchange them yet - maybe after two more years...

The Teflon piston valves also looked good.

http://www.saunalahti.fi/~animato/3003/PICT2142.JPG

Here, there was some slight wear (parallell lines in the Teflon), but nothing to worry about, at least not yet. The perforated center portion of the valve ring is recessed, and has darkened somewat. The edges are the only parts in contact with the valve cylinder, and it's there that I can see the slight wear. Next time around, I will turn new valve rings, an easy job.

The valve "liners" also showed some slight lines, but most of them did not even catch my nail when I ran it over them, so I won't need to hone the valve yet.


http://www.saunalahti.fi/~animato/3003/PICT2146.JPG


All in all, I was very surprised that the materials had stood up this well - as you know, this was a "new" design, that I have not seen in any books or magazines.
Here is the disassembled engine, less frame, cylinders and wheels. Quite a heap of parts, all to be cleaned before re-assembly...

http://www.saunalahti.fi/~animato/3003/PICT2149.JPG

Greetings from Finland,

Jan-Eric

[timz1999]

Did you inspect the boilrer? if i remember you used a cornish boiler (three tubes) and I would like to know how thats held up? maybe a picture? all in all it looks like it held up well.

[Jan-Eric Nystrom]

<font face="Verdana, Arial" size="2">Originally posted by timz1999:
Did you inspect the boiler?</font>

Not yet, but I will do it next week. I'll also make a hydro test to 180 psi.

(The working pressure is 100 psi, and the original hydro was to 230 psi, so I don't expect any problems.)

regards,

Jan-Eric

[Bill Shields]

J-E:

Good pictures..

I was one that mentioned the teflon valve rings in another topic.

Admittedly, my design for teflon rings was quite a bit different than yours, and I see that yours appear to be holding up quite well, and that you probably don't see a need to change them for a while. This attests to your original good design / construction process.

My design was a bit more coventional, using a teflon ring with a viton o-ring behind it to provide circumfrential pressure. This worked well for a while...but after a couple of seasons, began leaking and required replacement. This was 20+ years ago, and I don't know how many KM / Miles it ran, but it was a great more difficult to disassamble than your design, so I went conventional with cast iron rings against the steel sleeves in my welded-up cylinder castings. These have been working well for me for...well 20+ years.

I have been using o-rings for piston rings in my steam driven water pumps for 23 years, are the originals and have given me no reason to disassemble, so like you point out, properly done, these 'modern' materials work just fine.

Question about bearings...Have you ever tried NYLATRON for reciprocating bearings, like on the crosshead end of the main rod? You may not know it by that name, but it is a modybdneum disulfide impregnated nylon.

I tried bronze, cast iron etc: for a while on my Hudson, and eventually, they all wore out. Others may have good success, but I didn't.

I put in the nylatron 18 years ago and it is still tight on the pin, no lubrication other than self-lube.

I would NOT used this material on a rotary bearing, or one where I thought dirt might get into it, because like most synthetics, any dirt is destruction..but on the cross-head pin, it has been a life-saver.

I like your articles and your aggressive style. Even though I write software to convert CAD drawings into machine tool code for a living, I had never considered using a water jet cut part in our hobby until your "chicken"...now you have me really thinking every time I look at a new project.

Also...from where does the name 'chicken' come from? In the US, I dare say, I have never heard of anyone refer to a loco as a 'chicken'....pig, and a few other unprintable words, yes...but never a chicken.


[This message has been edited by Bill Shields (edited 11-10-2005).]

[GWRdriver]

Nylotron should also not be used where a significant rise in operating or ambient temperature will be expected because it has a relatively high co-effcient of expansion.

[Jan-Eric Nystrom]

<font face="Verdana, Arial" size="2">Also...from where does the name 'chicken' come from?</font>

I answered the "chicken" question where it was originally posted, i.e. in "Topic: Steam Chest castings", but I'll copy it here:


This type was really called "Chicken" by the crews, and even the general public! (Or, the "Hen" - that's just a matter of taste in translation from the Finnish "Kana".)

The reason? It's a switcher, so it was always pecking in its own yard... Also, it was the smallest of all modern Finnish steam engines, so the name stuck.

As I mentioned in the first part of the article (Sept/Oct), other designs were called "Roosters", "Ducks" (this because of the wagging motion), and one was a "Turkey"! (Without the connotation of U.S. use of that word - even though it was of U.S. Vulcan manufacture... http://bbs.livesteam.net//wink.gif )

Most Finnish engines had nicknames, a few after presidents, the post-war Baldwin and ALCO decapods were "Trumans", for obvious reasons...

regards,
J-E

[tel]

Nice series of pics Jan-Eric, very interesting.

'This type was really called "Chicken" by the crews, and even the general public! (Or, the "Hen" - that's just a matter of taste in translation from the Finnish "Kana".)' In that case it would be called 'CHOOK' over here

[Bill Shields]

Sorry, I have lost my copy of that version of LS, or I would not have asked...

OK, so the obvious question:

Is there a reason why Finnish locos were all named after largish birds?...

And yes, GWRDrvr: I forgot to mention about Nylatron and high temps...it IS a nylon derivative, and being an ex-duPont employee, staying ambient is obvious to me, but not necessarily so to others looking for solutions...sorry, getting lax in my old age.

[GWRdriver]

Fortunately I was spared this learning experience . . . . My first mentor, Paul Brien, in an attempt to apply more current technology to good advantage, used Nylotron/nylatron for all the bushings & bearings on his first loco, as well as the slide valves IIRC, and on first steamup it locked up solid. No one knew to allow for the high rate of thermal expansion.


[This message has been edited by GWRdriver (edited 11-10-2005).]

[Bill Shields]

Your mentor and my mentor are apparently different schools....mine is very old school (retired NYC signals engineer)...

I had to practically tie him down and gag him when I suggested we put a set of wheels on axles with loctite..OH NO, THAT WILL NEVER WORK!

He had accidentally bored a set of wheels a bit too big for a press fit (somehow a bar of 12 MM drill rod had ended up in the rack..what he had ASSUMED was ground .500" was...well a little undersize)...and was looking at either a new axle or.....so he 'allowed' me to 'try' my 'fancy new stuff'.....

Now, I can't get the little red bottle away from him....and he has a running engine with METRIC axles, much to his dismay...

And I have yet to figure out how I got a bar of 12MM drill rod...

[Jan-Eric Nystrom]

<font face="Verdana, Arial" size="2">Is there a reason why Finnish locos were all named after largish birds?...</font>

All? - No, certainly not! Here's a little pick of other nicknames (some translated):

Steam locos:

- Top Hat
- Bristoller
- Flash
- Wind
- Cloud
- Drone
- Granny
- Riksmont (from Richmond)
- Jumbo
- Little Jumbo
- Little Brownie
- Hurricane
- Hindenburg (made by Hanomag, Germany)
- Wilson (US made)
- Truman (US made)
- Risto (named after Finnish president)
- Ukko-Pekka ( -"- )

and some diesels:

- Flat Hat
- Carrot
- Zebra
- Siberian Wolf
- Teddybear

As you can see, we had more or less "nice" nicknames - no "unmentionables"...


<font face="Verdana, Arial" size="2">...and on first steamup it locked up solid. No one knew to allow for the high rate of thermal expansion.</font>

Well, I did have to take the expansion of the PTFE valves into account in my design. Otherwise, they would probably have locked up, too.

Since I don't have inside/outside micrometers for this size, I tested my machining of the rings by matching them to their tubes: At room temperature, they are an easy sliding fit, but cooled in cold tap water (i.e. less than 10° C), they drop through by their own weight, but heated in hot tap water (55° C) they need a slight finger push to slide through the valve tube. This means that they give a steam tight but still easily sliding fit at working temperature, i.e. around 120-160° C...

Greetings,

J-E


[This message has been edited by Jan-Eric Nystrom (edited 11-12-2005).]

[Bill Shields]

J-E:

Rather unique names from the USA perspective.

I would personally, be a bit wary of riding immediately behind a loco named Hindenburg.

For many years I supervised maintenance of a power plant that had hydrogen cooled generators...and naturally, we had our own hydrogen generation /compression plant with distribution pipes all over the facility.

One afternoon, a Korean construction worker cut into the wrong pipe...the one he cut into was..you guessed it, our hydrogen line.

Fortunately, he was not seriously injured, but did require a trip back to his apartment for a fresh change of underwear...

[railfancwb]

Jan-Eric Nystrom is too modest to mention it, but he has one heck of a web site. See

http://www.sci.fi/~animato/

Or if you are mostly interested in his live steam, look at

http://www.sci.fi/~animato/steam/index.html

Wonderfully detailed "how I did it" information on the Chicken, the predecessor American, and now a 4-6-0. Oh, yes. There is a non-steam loco also.

Charles