C.W. Woodson Vertical Single Steam Engine

[chucketn]

I am getting ready to mill/drill the steam ports for the C.W. Woodson Vertical Single, from the April 1947 issue of Popular Science. My build is not exactly to plan, so I have to make adjustments as I go. I cast the cylinder in aluminum, and lined it with a steel sleeve. My cylinder’s bore is 1 1/8”, where the plan calls for 1 ¼” bore.
My first question is, if running this engine on compressed air only, do I need to scale the port sizes up or down?
Next question, does anyone know of a good build thread or video on milling/drilling the steam ports? This is my first steam engine of this type. My available small diameter mills are 3 mm and 1/16”, both 2 flute or slot drills. I plan to drill out the port faces slots and clean them up with the slot drills.
Chuck

 

[chucketn]

Well now, 144 views in 24 hours, and no comments!

Let me re-phrase my question.

Does any one have an online reference(book/pdf/html/forum post) for the design/dimensions/requirements of the port size on a slide valve steam engine based on cylinder size?

I found one but it was quoted from a book written in German. I can't read German.

Chuck

 

[Gerhardvienna]

My first question is, if running this engine on compressed air only, do I need to scale the port sizes up or down?
Chuck

Hi Chuck
As far as I know, many builders do the steam ports equal for steam or air. The only difference is in the cylinders. While the air-engine has no liners built in, the steam engine will have.
Here is a good example for that, the engine was planned from Georg Held in Germany, (together with me). The shown engine runs on air!
[ame]https://www.youtube.com/watch?v=25oraf20Csk[/ame]
I have the original plans, but they are copyrighted from Georg, so I cannot "deliver" them in the download section.
Just looking forward to your build...............
Regards
Gerhard

 

[chucketn]

I want to make sure I understand how the slide valve works on the C.W. Woodson vertical I’m building.
There are 3 port slots on the port face, the center is the exhaust and the end ports go to the respective ends of the cylinder.
The slide valve is basically a flat block that is hollowed out on the port face side, the hollow being sized to cover the exhaust port and whichever cylinder port is being exhausted.
The steam chest guides the valve rod that moves the valve and provides the input for steam.
The valve rod provides for adjustment of the valve position. Valve rod moves under the influence of the valve eccentric, whose offset is determined by the amount of valve movement needed.
The slide valve is held to the port face by steam pressure.
Does it sound like I understand it?
Chuck

 

[canadianhorsepower]

[I found one but it was quoted from a book written in German. I can't read German.

Chuck[/QUOTE]

I have German buddy that could translate it for you

cheers
Luc

 

[Gerhardvienna]

Hi Chuck
YES!, it sounds like that.
The size of the ports are depending to the bore and stroke of your engine, for a bore of around 20mm and stroke around 30mm a steam port of 2 - 3mm will be enough. Sorry for measuring metric, I`m not that firm in inches-measuring:wall:
For a slow runner 2mm steam intake ports will be enough, for a fast running engine 3mm would be good. The exhaust port can be a bit larger, but not too much. The engine from the video above has only 1,5mm steam ports, at a bore of 14mm and stroke 20mm.
Regards
Gerhard

 

[chucketn]

Gerhard, thanks for the reply. Don't know how I missed it. I will convert your numbers and compare to mine. I'm guessing better to go a bit bigger than too small.
Got the standard cast and cleaned up a bit. Now trying to decide if I should sleeve the crosshead bore in the aluminum standard or if a brass crosshead will run in an aluminum bore.


Chuck

 

[ShopShoe]

Chuck,

You asked:

"I want to make sure I understand how the slide valve works on the C.W. Woodson vertical I’m building.
There are 3 port slots on the port face, the center is the exhaust and the end ports go to the respective ends of the cylinder.
The slide valve is basically a flat block that is hollowed out on the port face side, the hollow being sized to cover the exhaust port and whichever cylinder port is being exhausted.
The steam chest guides the valve rod that moves the valve and provides the input for steam.
The valve rod provides for adjustment of the valve position. Valve rod moves under the influence of the valve eccentric, whose offset is determined by the amount of valve movement needed.
The slide valve is held to the port face by steam pressure"

That's pretty much how a slide valve works. You just need to be sure that you provide a way to adjust movement and timing when you are ready to run it.

--ShopShoe