Hi Alex,

As you found out from the Helen Long drawings, a lot of the dimensions
on LBSC's drawings do not tally! The problem is that he built by eye
rather than from drawings and most of the drawings he did do were done
from memory after the locos were built.

I picked up a set of Dyak frames and cylinders recently so I did start
to make a set of full size drawings for use when I get around to
finishing the loco. I haven't got so far as doing a general
arrangement drawing so haven't picked up the errors that you have found.

LBSC did say in the ME articles that the exhaust and bolting holes in
the frames were based on the original Helen cylinders and using these
with different cylinder castings would result in the cylinders being
'slightly' inclined, although how much 'slightly' is I am not sure. By
my reckoning, to bring everything level the inlet and exhaust holes
and the bolting holes in the frames all need to be lowered by 5/32" !

RE crosshead clearance: LBSC does suggest that the back of the
crosshead may have to be filed to clear the coupling rod.

Not sure about the weighshaft problem.It is unlikely that the axle
boxes will move much on modern tracks which tend to be fairly even so
I doubt if they will ever reach the top of the horns. One thing I have
noticed is that the centreline of the radius rod falls 3/32" below the
centreline of the weighshaft so in mid gear the lifting arm will not
be level anyway but will point downwards.

It will be interesting to hear any comments from the Dyak
builders/owners out there.

John

PS Still haven't sorted the middle cylinder layout for Helen Long!