Mystery steam engine

[chris123]

The only thing critical are the ports and the valve edges.
Nothing else matters much.
.

Thanx green twin
I just make that he valve lies on properly on
The valveface centered and thats it
Chris

 

[GreenTwin]

Even if the port face is at an angle, the valve will still ride flat on it.
The valve should be able to float a bit on the rod, and not be attached tightly to the rod as far as movement away from and towards the port face.
This was how the old D-valves were able to automatically take up wear.
.

 

[Jasonb]

Well with the buckle design you do need it to be quite close to parallel as if the valve is tilted too much it will become tight in the buckle and won't be able to move relative to the face.

The hole position which we have been talking of is also quite critical on this as there is not a lot of clearance in the valve so it needs to be within say +/-0.005" or 0.13mm if the valve is to have some movement. To little and the valve will be held tight to the port face and will also make the valve rod bind. Too much and it won't make contact with the port face and you will just leak steam/air

 

[GreenTwin]

I think the metric/imperial thing is like Chevy/Ford.
You are either a "Chevy" person, or a "Ford" person, but you are not a little of both.
At the race track, there were Chevy, Ford, and Hemi folks, and there was a huge rivalry.
And they all thought their brand was the best, but well all know Chevy is best, but I must admit those Hemi's were hard to beat.

I have metric tools because the cars and tractors use metric fasteners, but I don't stock metric fasteners, and I never will.
Keeping up with one set of fasteners/taps/dies is plenty.

The building industry here still uses feet, inches, pounds (weight), etc.
It is very convenient to build around standard sized items, like 4x8 plywood, 2x4 studs, standard floor tiles sizes, plumbing pipe sizes, etc, etc.

If I lived in Europe, no doubt I would be a "Metric" person.
I think many here have rejected the metric system, because they don't think it is better, it is just different.
Machines and equipment here that are configured into assemblies seem to have gone metric.
Buildings and large sitework are not metric.

I think I am getting off-topic here.
.

 

[chris123]

Maybe
Bud you are right green twin
Chris

 

[Charles Lamont]

The hole position which we have been talking of is also quite critical on this as there is not a lot of clearance in the valve so it needs to be within say +/-0.005" or 0.13mm if the valve is to have some movement. To little and the valve will be held tight to the port face and will also make the valve rod bind. Too much and it won't make contact with the port face and you will just leak steam/air

In designing the valve I had to deal with the valve rod seemingly being very close to the portface. This is why the exhaust cavity is shallower in the middle of the width. Now we know different, the hole through the valve could be made larger, 8mm or even 9mm.

While a lot of stuff in the UK is genuinely metric, boards are still 8 x 4, they are just designated as 2440 x 1220.

 

[chris123]

In designing the valve I had to deal with the valve rod seemingly being very close to the portface. This is why the exhaust cavity is shallower in the middle of the width. Now we know different, the hole through the valve could be made larger, 8mm or even 9mm.

While a lot of stuff in the UK is genuinely metric, boards are still 8 x 4, they are just designated as 2440 x 1220.

Hi charles
I can make the hohle bigger
That means it wouldent matter if paralell or not
The buckle have to be accurate isnt it?
Chris

 

[chris123]

Hi charles
I can make the hohle bigger
That means it wouldent matter if paralell or not
The buckle have to be accurate isnt it?
Chris

I actually didnt drill that hohle yet
So u could change things if needed
Chris

 

[Charles Lamont]

That means it wouldent matter if paralell or not

Depends how far off it is. How much is the port face out of parallel to the valve spindle? Are you sure the valve spindle is vertical?

 

[chris123]

Depends how far off it is. How much is the port face out of parallel to the valve spindle? Are you sure the valve spindle is vertical?

I double check
Chris

 

[chris123]

I double check
Chris

Hi charles
I got on the top valve about 9.5mm
The bottom center blackened an marked
With sharp centered rod is 8.1 mm
So Over 36.195 mm sbout 1.4 mm
Chris

 

[chris123]

What do u reckon charles
What should i do with the hohle?
Chris

 

[chris123]

fabricating the cocks

 

[Charles Lamont]

Chris, you need to make the hole in the valve big enough, and put it in a position so the rod will pass through with clearance all round. Working from your measurements it looks as though it wants to be half way, 8.7 mm from the face. I suggest you start small, and open up as necessary, perhaps with a file. The hole does not have to be a perfect shape, it just has to be clear of the rod over its range of movement. I can't really be more specific than that.

Nice drain cock.

 

[chris123]

Chris, you need to make the hole in the valve big enough, and put it in a position so the rod will pass through with clearance all round. Working from your measurements it looks as though it wants to be half way, 8.7 mm from the face. I suggest you start small, and open up as necessary, perhaps with a file. The hole does not have to be a perfect shape, it just has to be clear of the rod over its range of movement. I can't really be more specific than that.

Nice drain cock.

Ok i understand
I get it done i make 2 cocks for underneath
And solder small pipes on which go down on the front
The brass is not here yet for the buckle
The flywheel can be smalker and thicker also isnt it? As long the wheight is same
I got dia 100 here cast
Thank you charles

 

[Jasonb]

Charles, with the valve being tilted about 2.5degrees from the buckle do you think there is a risk of it either not being able to seat fully or not being able to lift as the racking could make the valve tight in the buckle top and bottom where we want minimal clearances?

 

[GreenTwin]

If the valve rod is fixed, and cannot rotate, it could be perhaps shaved off on the side facing the valve to give a little extra clearance.
.

 

[Charles Lamont]

Jason - I agree, the buckle will need to be eased to allow the valve to tilt. Slighly rounding the inside end faces should do it. Alternatively, the working face of the valve could be remachined at the required angle to make the back and the hole parallel to the rod. (I am not totaly convinced about the nature of this problem anyway.)

With a flywheel it is the moment of inertia the matters, so for a given mass the larger the diameter the better, as well as concentrating the mass at the rim.
100mm should be fine if that is what you have available.

 

[chris123]

Jason - I agree, the buckle will need to be eased to allow the valve to tilt. Slighly rounding the inside end faces should do it. Alternatively, the working face of the valve could be remachined at the required angle to make the back and the hole parallel to the rod. (I am not totaly convinced about the nature of this problem anyway.)

With a flywheel it is the moment of inertia the matters, so for a given mass the larger the diameter the better, as well as concentrating the mass at the rim.
100mm should be fine if that is what you have available.

Thank you charles