Valve operation on the 5″ Schools locomotive by Neville Evans

[Tony EscottParticipant @tonyescott89409]

Has anyone building this locomotive had problems with the valve operation set up?

MIDDLE CYLINDER VALVE

With the radius rod held at the top of the expansion link the crosshead over-travels the rear of the valve guide by 3mm but is correct when the crosshead is at the cylinder end of the guide.

With the radius rod at the bottom of the expansion link the crosshead still over-travel the rear of the valve guide by 1,5mm.

I have checked the measurements of various items and their location. Checked the 9.5 degree positioning of the eccentric on the crank shaft.

I could bring the cylinder or the valve guide back a little but then the crosshead will over-travel at the cylinder end.

It looks as though I will have a similar problem with the outside cylinders and valve gear.

Any ideas will be most appreciated.

Tony

[Tony EscottParticipant @tonyescott89409]

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