Locomotive cylinder & piston valve fabrication

[John R. Griggs]

I would like any information on fabricating
steam cylinders and piston valves from steel
tubing for a 1.6" scale locomotive.

[Curtis_F]

<font face="Verdana, Arial" size="2">Originally posted by John R. Griggs:
I would like any information on fabricating
steam cylinders and piston valves from steel
tubing for a 1.6" scale locomotive.</font>

I can be done.

What else would you like to know?


Ok. enough of me being a butt-head. http://bbs.livesteam.net//wink.gif I believe that this topic was covered in past issues of live steam by Bob Reedy in his series on building a Mogul.

And Bob learned his tricks from Ed Yungling, builder of the infamous 7 1/2" gauge Cab Forward here in California.

Fabricating piston valve cylinders can be easy or hard depending on what look you want. A Vulcan Compound or a Alco 3 Cylinder can be neigh impossible, a cylinder for a Southern Pacific 4-8-2 is hard, a cylinder for a Southern Pacific GS-4 is easy.

Difficulty depends on if the exhaust passages are internal or external & how much extranious detail you want.

The basics are that you need a Cylinder Spreader: http://home.earthlink.net/~carsoncolorado/fab_cylinders/Cyl-01.jpg

Then Attach the Cylinders using bolts through the spreader and screwed into the cylinder wall: http://home.earthlink.net/~carsoncolorado/fab_cylinders/Cyl-02.jpg

Make the Front and Rear Sheets (around 1/4" material for 1.5" / 1.6" scale), bore out the holes where the Cylinders and Steam Chests are going to stick through. Not the small holes just inside of the Cylinders, those are the exhaust ports pipe-tapped from the inside out: http://home.earthlink.net/~carsoncolorado/fab_cylinders/Cyl-03.jpg

Fit up the Steam Chests. Make sure they're securely located by the Front and Rear Sheets. You may want to make a large welding jig that locates the Cylinder bores to the Steam Chests just to ensure parallel alignment: http://home.earthlink.net/~carsoncolorado/fab_cylinders/Cyl-04.jpg

Attach the Exhaust Passages that take exhaust steam from the Steam Chests to the afore mentioned pipe-tapped exhaust passages: http://home.earthlink.net/~carsoncolorado/fab_cylinders/Cyl-05.jpg

Weld in the internal Steam passages that guide steam between the Chests and the Cylinders: http://home.earthlink.net/~carsoncolorado/fab_cylinders/Cyl-06.jpg

A flat plate can be welded into place just under the saddle part where the exhaust lines can be routed to and then a Exhause Nozzle can be bolted to that plate.

Put holes in the Steam Chests that let you look into the valve chamber to see the location of the piston valve in relation to the steam ports. You'll need these ports when timing the engine. Simply put a pipe plug into them after timing.

Make the Valve liner out of a single piece if at all possible. The prototypes uses two pieces each pressed in from one end, which is a buggar to get them spaced properly. Much easier and more accurate to just press in a single piece.


Well, that's the nickle tour around fabricated piston valve cylinders.


Cheers,

Curtis F.

[pockets]

Check the May, 1993 Modeltec. An Article about fabricated piston valve cylinders.

Sorry, Clover.

[This message has been edited by pockets (edited 03-04-2005).]

[andypullen]

There was an article in 1977, September I think, by Bill Van Brocklin about silver soldering up bronze cylinder assemblies. I've read and reread that article many times. I'll dig the article out and run a copy for you if you want.

Bronze could be an option if you worry about corrosion. Seems to me that steel would be harder to seal. Even with a highly qualified tig welder doing the job. I know it can be done since others have done it, though.

Nice work, Curtis. I'll have to keep what you posted in mind when I do my articulated.

I agree with you about the pipe plugs. I've made them for N&W #1218 and #611 when they were running. They were about equal to 1 1/2" pipe threads. 3/16" or 1/4" square or hex heads will be prototypical in this instance.

Thanks,

Andy Pullen

[This message has been edited by andypullen (edited 03-04-2005).]

[BillB]

OK Curtis, that deserves some kind of award for most informative concise reply to an awfully broad question.

Nice website, too.

BillB

[Curtis_F]

Thank guys for the kind words. That's information that was passed on to me so I felt it only right to keep it passing around.

Also, I wanted to add that Ed Yungling scales the Valve Gear & Cylinder Port spacing on his models. Now I was always taught that when you scale an engine that "steam doesn't scale" and that you have to make exceptions in the Valve Gear and Cylinder block. Not Ed. He scales it all, and ALL of his engines run better than any Swiss watch.

By my logic they shouldn't work well, but his engines perform in power, firing and sound better than most engines with a reengineered Valve Gear.


Cheers,

Curtis F.

[andypullen]

I've only seen Ed's models in Live Steam. Going waaaaay back into the '70s. He's a builder like Bruce Hamilton, Joe Mastrorocco or Fred Bouffard in the east. (Sorry to anybody I missed, I know there are many prolific builders.) 3 true craftsmen. Their engines all look like a million bucks and run like they look.

I'll be sure to print out what you posted for my future projects...Thanks.

Andy Pullen