Mystery steam engine

[Charles Lamont]

If the eccentrics have been made as pairs in one piece then there will be a fixed angle between the two sheaves and we can work backwards from that to find the intended valve lap (ignoring lead). If the eccentrics are separate they may have been set, and then again they may not.

 

[chris123]

Amazing work jason
Awsome
The right valve gear is very stiff
Thats why the crank is hard to move
I check straight away the eccentric again

 

[chris123]

Hi jason and charles
The ofsett is
If jason could match 360degrees
Over the flange then some degrees could be
Obtained easy??
Chris

 

[Jasonb]

That is very close to 1/4" = 6.35mm so we can assume that is what the builder was aiming for.

Depending on how far the curved expansion links can move you may or maynot get the same movement at the valve rod.

The four ctr drill holes suggest one for each eccentric, not sure if they would have been used to turn them insitue or whether they were used to clock the eccentrics in once fitted to the crankshaft.

Can you take a Sharpie or similar and mark the position of the two crank pins on the flange, it looks like one is at about 4 o'clock and the other at 8 o'clock

 

[Charles Lamont]

From the latest photos there is a fillet radius between an eccentric and the bit of plain shaft between the sets, suggesting that the eccentrics are made as one piece with the shaft. There should not be a problem with slackening the eccentric straps, if that will ease the shaft. Or any of the other bearings.

 

[chris123]

Hi jason yes the centerhohles are for crankshaftturning
Thats why i thought the thing with the degrees
However the crank pins for the pistons
I will send
The valves are just eccentrics i think
Bud have to do it t morrow
Chris

 

[chris123]

Hi jason yes the centerhohles are for crankshaftturning
Thats why i thought the thing with the degrees
However the crank pins for the pistons
I will send
The valves are just eccentrics i think
Bud have to do it t morrow
Chris

Ok now
Hi jason ithink i got the go
Look the crankpins are on 9 and six
And the high point of the valve eccentric
Is about 2 and may 2 30 for the 2 in the middle visible on the flange
The outer ones the high point of eccentric corresponds with the left side crank pin 6
With about 10
The other the right towards 9 crank pin
The hogh point of eccentric points at 5
Visible on flange
The big cylinder is right
The small is left
I hope i explain understanable?
Check it out

 

[Jasonb]

We should be able to work with that, I can get the angles with CAD

 

[Charles Lamont]

That looks right. Don't have much time this morning but looking at centres on flange: 10 o'clock - HP clockwise, 2 - HP anticlock, 1 - LP clock, 5 - LP anti. If we can have the outside diameter of that flange Jason can do his technique of scaling from a photo to get a pretty accurate drawing.

 

[chris123]

Sorry charles phone on charge
30.298
About

 

[chris123]

Sorry charles phone on charge
30.298
About

 

[chris123]

Actually 295

 

[Jasonb]

It is not quite as I would expect.

I used another image that was squarer on and rotated it to match the position in post #247. Added th eposition of the two crank pins.

LP looks as I would expect with the eccentrics leading the crank by 90 + approx 120deg

But the HP seems to be only show a lead of 60deg as the crank pin is at the top, the eccentric positions seem more suited to the pin at the bottom

Though I could be completely wrong.