Stephenson valve system

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Steamer Al
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Re: Stephenson valve system

Post by Steamer Al »

Looking at your drawing I make your port bridges out to be .15625 each
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Bill Shields
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Re: Stephenson valve system

Post by Bill Shields »

If the spacing between the ports is different than what can be deduced from your earlier drawing...then check everything.

1/2" of valve travel should work.
Too many things going on to bother listing them.
Emfinger
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Re: Stephenson valve system

Post by Emfinger »

Bill Shields wrote: Sat May 29, 2021 8:33 pm The space between the ports can be determined by basic math...assuming the shown dimensions are correct.
Yes, it is basic math, sorry...
Emfinger
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Re: Stephenson valve system

Post by Emfinger »

Hello Guys, OK as you know, I'm into the final adjustments. There is a bunch of linkage under the boiler with all kinds of connections all of witch have 40 years of ware. But when there is (a bunch) of them the slack adds up.
Now what? How do I bush the slack out of several small parts?
I guess I can't evaluate the valve system until the slop is gone.
Thanks guys.
Last edited by Harold_V on Mon May 31, 2021 1:26 am, edited 1 time in total.
Reason: to remove undesirable language
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NP317
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Re: Stephenson valve system

Post by NP317 »

One of my Pandemic Isolation Tasks (PITs) was to R&R the well-used and now-sloppy Stephenson valve under my Allen Ten Wheeler.
I machined new clevises and pins, hardened them all, and enlarged worn holes for matched diameter pins.
The slop is all gone now and I am slowly working through the system to get the valve timing balanced and square.
The eccentrics had no wear and had not moved, and the straps were still good too, so I do not need to retime their positions on the axle.

It does feel like a big chore, but get the loco where you can work underneath it, and take it one bite at a time.
First: Determine what is worn and what is still OK. Then get to work.
It's not really as bad as eating an elephant...
RussN
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Bill Shields
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Re: Stephenson valve system

Post by Bill Shields »

Options are to fix it or leave it sloppy

Start at each eccentric and move forward

Like Russ says. Eat the elephant
Too many things going on to bother listing them.
Emfinger
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Re: Stephenson valve system

Post by Emfinger »

Well the good news is that the boiler is off the frame.
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Bill Shields
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Re: Stephenson valve system

Post by Bill Shields »

always step 1 with Stephenson gear....kind of like the old British cars:

1> Step 1 -> remove engine
Too many things going on to bother listing them.
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NP317
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Re: Stephenson valve system

Post by NP317 »

Emfinger:
Good to hear the boiler is off the frame.
Rebuilds and repair will be SO much simpler that way.

Last year I machined new valve gear for an acquaintance's Ten Wheeler project.
It was simple with the bare frame. Pic attached.

Keep us informed on your progress.
RussN
IMG_3704.JPG
IMG_3705.JPG
Emfinger
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Re: Stephenson valve system

Post by Emfinger »

Very nice.
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