I cancelled this message which went out incomplete. I resent the complete one a few minutes later.
The only reason for the analogy was because you seemed to have difficulty thinking about it in degrees. The result is the same - at the crank.
No. It is irrelevent what the angle of the cylinders is. It is a property of using a crank shaft or axle to convert reciprocating motion into rotation.
The pistons must be at their extremes when the crank is at to dead centre.
And the explosion, steam admission/exhaust, etc happens (simplistically) when the piston is at top dead centre. Which means when the crank is at TDC.
So if one of the three cranks is not symmetric with the other two, the beat cannot be symmetric.
piston, even though it
Mechanically it has to.
No, you didn't. You used the clock analogy which only works at the crank axle. A clock is a continuous rotation, not reciprocating.
And how does that allow it to fire at 4 o'clock when the crank is at
4.30?
that cylinder would have
difference of the center
That still does not permit a beat at 4 o'clock with the crank at 4.30.
in the Gresley system
timing you can derive
times. If the valve timing
with one cylinder
valve got later and
direction, so that 7
become steadily worse!
And I'll leave you to work out what happens when you move the valves further along the valve spindle with respect to the steam ports to compensate for the angle.