Slide valve

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Emfinger
Posts: 229
Joined: Tue Oct 01, 2019 3:30 pm
Location: Yucca Valley, CA

Re: Slide valve

Post by Emfinger »

Bill Shields wrote: Sun Jun 13, 2021 4:25 pm If this information is not available...then the request for someone to build you a valve is somewhat of a non-stzrter.
What engine do you own?
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Bill Shields
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Location: 39.367, -75.765
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Re: Slide valve

Post by Bill Shields »

I fail to see what that has to do with the make a valve information...but if you want to know...then

I have built and own / run

3/4" hudson with baker piston valves
3/4" tom thumb with eccentric slides converted to Stephenson
1-1/2" 2-8-0 with stephenson slides
1" 2-4-0 with southern slides

Built but no longer own
3/4" 0-6-0 with baker piston

Own but did not build

3/4" tich with eccentric slides
1/2" 4-6-0 baker with slides

Then there is a 3/4" Atlantic that i am finishing for a good friend who did not live to finish. He did most of the chassis.. I did the walscherts valve gear and boiler.

I can assure you that I know quite a bit about loco valve gear and know what questions to ask when designing a slide valve.
Too many things going on to bother listing them.
Emfinger
Posts: 229
Joined: Tue Oct 01, 2019 3:30 pm
Location: Yucca Valley, CA

Re: Slide valve

Post by Emfinger »

send pictures
Emfinger
Posts: 229
Joined: Tue Oct 01, 2019 3:30 pm
Location: Yucca Valley, CA

Re: Slide valve

Post by Emfinger »

Dave, I may be misreading the post but the pictures and the words seem to conflict they talk about Lap and others say Lead.
I'll read it a few more times.....hell, I'm less than two years into the hobby and 77 years old.
Tom
Emfinger
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Joined: Tue Oct 01, 2019 3:30 pm
Location: Yucca Valley, CA

Re: Slide valve

Post by Emfinger »

Builder01 wrote: Sun Jun 13, 2021 5:06 pm How has it been determined that the existing slide valve is not correct?
The Stephenson gear is tight and properly timed. My problem is when the piston is at FDC (I call it forward dead center) and the lead is set to about 0.015" and the wheel is turned forward the port becomes fully uncovered. Turning the wheel to BDC (bottom dead center) there isn't any lead in fact I have to turn the wheel a lot more to get the back port uncovered, but it is never fully uncovered.

The valve rod has a total travel of 1/2"
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Builder01
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Re: Slide valve

Post by Builder01 »

Sounds like you need to reset the valve on the valve spindle to get equal movement over the ports. A properly functioning valve does not have to completely uncover it's port. This is especially true when it's notched up.
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Builder01
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Location: Erie, PA

Re: Slide valve

Post by Builder01 »

After you set the valve for equal movement over the ports, if the timing is now off, the eccentrics have not been set correctly.
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Bill Shields
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Re: Slide valve

Post by Bill Shields »

Emfinger wrote: Mon Jun 14, 2021 6:04 pm send pictures
Of what do you want pictures and what does that have to do with your valve problem?

If you remember I while back - i asked if the eccentrics were correctly set and why it has been determined that your existing valve is incorrect...so it appears that we are going full circle.
Too many things going on to bother listing them.
Kevin S
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Joined: Sun Apr 11, 2010 4:11 pm
Location: Rocklin, CA

Re: Slide valve

Post by Kevin S »

Do you have drawings for your engine, to compare your slide valves with the drawing, also with the ports to the drawings? How have you determined that the eccentrics are in the right location? I have seen some eccentrics that are set to the proper angle to the drawing and still be off a little and needed to be adjusted some to achieve proper valve movement.
What people have asked for is key information to help design the slide valve you are wanting and you have given nothing in return.
-Kevin S.
VGC
Posts: 111
Joined: Tue Sep 22, 2009 3:17 am
Location: Europe / earth - yet in freedom ;-)

Re: Slide valve

Post by VGC »

If a PC user wants an IT specialist to tell him which button to press when any error occurs, the result certainly will not be the specialist showing him this button. And this is not because the specialist is unpolite.

Understanding this could be helpful if the PC user does not want to be nicknamed "Tamagotchi" soon.

Just a hint...
David Powell
Posts: 523
Joined: Thu Mar 13, 2003 10:38 pm
Location: Pickering Ontario Canada.

Re: Slide valve

Post by David Powell »

The school of telephone or internet instruction is beset with problems., misunderstandings and consequent failure to solve puzzles .Some 25 yrs ago I got a phone call from a fellow 100 miles away about valve timing. After several calls we decided that the only answer was to visit him, I drove over in my ancient pick up and began a long lasting friendship.
Your best answer would be to visit or host a fellow live steamer with experience, and listen and watch while he or she examines your model.
I do not know how far other folk will go to help beginners. Now, at 71 I do not have the time or energy to do more than give advice, and most certainly will not design, build or rebuild major parts of other folks projects. That said, a few hours helping out makes a cheerful change from my own ( Mis) adventures.
Regards David Powell.
thunderskunk
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Joined: Mon Jul 31, 2017 8:24 pm
Location: Vermont

Re: Slide valve

Post by thunderskunk »

Emfinger wrote:Duh !
I’m surprised anyone is responding to this, you’re all better persons than I could be.

You asked Bill to list off the engines he’s built with pictures to prove he knows what he’s saying, but I can tell from just one word that I wouldn’t want you as a customer.
"We'll cross that bridge once we realize nobody ever built one."
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