question about correcting error introduced by using straight slide in valve gear

[Chris KaminskiParticipant @chriskaminski64716]

I have two drawings from K.N.Harris setting out how to correct error
introduced by using straight slide.
Both of them based on Greenly and mostly identical,
but for one dimension (that I have highlighted in red)

as far as I can see in one (from article about JMG) – “L” appears to be vertical, when vibrating lever is at FDC…

in another (from article about Radial gears) – it appears to be in line with vibrating lever…

which one is correct?

please (and why?)

[duncan webster 1Participant @duncanwebster1]

Which articles, without context can’t say?

When he says ‘correction’ it needs to be taken with a pinch of salt. Better than a straight slide, but curved can be better. KNH didn’t have the benefit of computer models, so couldn’t fully see the effect of various dodges. In any case, Heywood used the offset top joint when Greenly was still a boy in short pants.

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