# Custom machining work for steam engine parts?



## Amber (Jul 29, 2011)

Does anyone here do custom machining of steam engine parts? I don't have the necessary tools to make certain things, such as the pistons for steam cylinders that I put together. I haven't found a way to make pistons for the cylinders. The cylinders are brass, I was going to use a piece of stainless rod for the pistons, but I don't have a way of machining it. I'm not sure if it's the right material to use, but the rod has a nice fit in the cylinder and it won't rust.


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## gra2472 (Mar 1, 2009)

try www.emachineshop.com. Make your own drawings on their free cad sofrware and order parts. It's very expensive for one off parts but it's and option.


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## Charles (Jan 2, 2008)

Amber

Have you tried the sponsor of the forum?


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## Phippsburg Eric (Jan 10, 2008)

Amber-- I have a lathe and small mill, as do several other folks. I know I would be happy to do a small project for you as, I am sure others would be.


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## steamtom1 (Jan 2, 2008)

For small parts, Jim Sanders, of Wee Bee Loco Parts might be considered. He may be able to also do some custom parts. His work is quite good. Pop him an e-mail, [email protected].


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## Amber (Jul 29, 2011)

At this point, all I need to have made is a set of pistons to use in a set of brass cylinders that I've made. I don't know if stainless steel would be a good material to use for the pistons, but the piece of rod that I have fits in the cylinders nicely.


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## Kovacjr (Jan 2, 2008)

Amber, no you would not use SS for the piston itself but you can use it for the rod, typical 1/8" in our small scales. The piston would be brass typically and be threaded or pressed on but can be soldered also to the piston rod. Soldering allows for a loose fit and allowing the piston to be crooked on the rod. The biggest concern is the bore ID and the piston rod length to connect to the crosshead or the main rod. The length of the piston rod is imperative as too long and the piston will hit the front cover and too short the piston will hit the back cover.


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## Amber (Jul 29, 2011)

I guess I'll need to find a piece of brass rod stock for the pistons then. the stainless rod measures .375 with my caliper and the inside of the cylinders measures .378 I could go with stainless piston rods. I think threading the rod into the piston would be easier for me. I would imagine that the length of the rod could be adjusted a bit where it threads into the the part that rides in the guides.


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## Kovacjr (Jan 2, 2008)

Amber said:


> I guess I'll need to find a piece of brass rod stock for the pistons then. the stainless rod measures .375 with my caliper and the inside of the cylinders measures .378 I could go with stainless piston rods. I think threading the rod into the piston would be easier for me. I would imagine that the length of the rod could be adjusted a bit where it threads into the the part that rides in the guides.


Doesn't much matter to have to find a exact rod for the bore as it needs to be turned down smaller than the bore anyway. You also need to make a critical groove in the piston for a Oring or packing. Yes the thread can be adjustable but when set it needs to be permanently affixed to the piston.


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## ScottB (Jan 8, 2010)

Jason, 

What is the reason for using the same metals for both the cylinder and the piston? I was under the impression that two different types of metals were to be used due to wear factors, Metals of the same could have a tendency to gall as they both wear the same. I do understand that the piston should not really have much contact in the bore as it will be slightly undersize and the O ring will be making the contact. Are the same metals used due to thermal expansion? I am not questioning your reply, I am just looking to further my education. 

Thanks, Scott


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## TrotFox (Feb 15, 2008)

Scott,

Brass and cast iron are two of the very few metals that can safely be used together in this way. This is because they are somewhat self-lubricating, the brass due to lead in the allow and the cast iron because of graphite in the metal. During those infrequent (but somewhat unavoidable) moments when a piece of metal touches another piece of metal due to insufficient oil the parts barely wear at all, greatly extending the life of the part. If stainless rubs against stainless without proper lube you get galling, where the metal stretches and rolls up, frequently locking the parts together.

With stainless/brass combinations you expect the brass to be sacrificial in the event of lube failure and in prototype practice it is usually replaceable.

Trot, the bearable, fox...


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## Chris Scott (Jan 2, 2008)

Amber said:


> Does anyone here do custom machining of steam engine parts? I don't have the necessary tools to make certain things, such as the pistons for steam cylinders that I put together. I haven't found a way to make pistons for the cylinders. The cylinders are brass, I was going to use a piece of stainless rod for the pistons, but I don't have a way of machining it. I'm not sure if it's the right material to use, but the rod has a nice fit in the cylinder and it won't rust.


Amber,
"...steam cylinders I put together." I'm figuring you did not machine the cylinders and I was wondering if they perhaps came from another loc, maybe a Ruby? Orphaned Ruby cylinders are not uncommon as many upgrade to larger ones. If yours are Ruby cylinders you can buy replacement cylinders from Accucraft. Just a suggestion.

Did your cylinders come from another loco?


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## Kovacjr (Jan 2, 2008)

ScottB said:


> Jason,
> 
> What is the reason for using the same metals for both the cylinder and the piston? I was under the impression that two different types of metals were to be used due to wear factors, Metals of the same could have a tendency to gall as they both wear the same. I do understand that the piston should not really have much contact in the bore as it will be slightly undersize and the O ring will be making the contact. Are the same metals used due to thermal expansion? I am not questioning your reply, I am just looking to further my education.
> 
> Thanks, Scott


 
Scott - The parts do not touch. The need a gap to work. The Oring or ring is the seal. Brass is by far easier to work with over Stainless.


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## ScottB (Jan 8, 2010)

TrotFox and Jason, 
Thanks for the explanation on Brass vs stainless. It all makes perfect sense now. 
Scott


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## David Leech (Dec 9, 2008)

Scott,
I have an Aster oscillating cylindered 0-6-0 where they had used brass for both the cylinder and piston (no o ring or seal of any kind) and regardless of lubrication as the metals expanded it would grind to a halt.
I had a friend make me up a stainless piston replacement and it was like night and day and runs well and long.
All the best,
David Leech, Delta, Canada


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## xo18thfa (Jan 2, 2008)

David Leech said:


> Scott,
> I have an Aster oscillating cylindered 0-6-0 where they had used brass for both the cylinder and piston (no o ring or seal of any kind) and regardless of lubrication as the metals expanded it would grind to a halt.
> I had a friend make me up a stainless piston replacement and it was like night and day and runs well and long.
> All the best,
> David Leech, Delta, Canada


On your 0-6-0 is the portface brass too? If so, the next upgrade could be a bronze cylinder. Brass portface, bronze cylinder and stainless piston is a perfect combination. Bronze is very durable, the stainless will never wear it out.

You coming to Sacramento this summer?


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## Amber (Jul 29, 2011)

My cylinders are home made from brass tubing and other brass parts


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## bille1906 (May 2, 2009)

Amber
I have a couple of complete Ruby cylinders and various Ruby pistons and rings which will work in your cylinders which you can have. Let me know if you are interested.


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## toddalin (Jan 4, 2008)

I belong to another web site, "The Home Machinist" devoted to machining (CNC/lathes/mills/etc.). They actually have forums for "live steam" and "riding-scale" model train engines/parts. They also have forums for maching offered/wanted. Maybe someone there can help you out.

http://www.chaski.org/homemachinist/


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## Amber (Jul 29, 2011)

Bille 1906, of course I'm interested, that would save me a lot of headaches! 
Thanks for the link toddalin, I'll check it out.


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## bille1906 (May 2, 2009)

Amber 
Do you want the complete cylinders or just the pistons and rings.
Send me a PM with that info and your address and I will get them off to you


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