Hello, MMD readers. The rebuild of my Steck upright Duo-Art is about
70 percent completed. I have rebuilt everything I could lay my hands
on in the lower action, and two of the three valve and pneumatic decks
in the upper action; just the middle one to go.
When I removed the spoolbox and all the other attachments above
the three decks, I discovered for the first time that I had acquired
a player with cross valves, and with pneumatics of three different
sizes, the largest in the bass register and the smallest in the treble
register.
I'm aware of the debate that persists between those that insist that
cross valves were the invention of the devil, and those that consider
them to be the next best thing to sliced bread, although I suspect that
cross valves came before sliced bread was readily available. Anyway,
I am keeping my cross valves.
My query is about the desirable range of travel to which the valves
should be set. I have settled on 0.035" for the treble register
(smallest pneumatics), 0.037" for the middle register, and 0.039" for
the bass register (largest pneumatics). Well, that's what I was aiming
for; in fact, the travel varied by as much as 0.002" between adjacent
valves.
I have completed the top deck and the bottom deck and tested the valve
and pneumatic behaviour with a vacuum of 7" on my water manometer.
This is just on the bench, without the pneumatics having to lift the
wippens.
They all seem to work okay when I take my finger on and off the brass
tube(s) that connect each pouch to the atmosphere. However, if more
experienced rebuilders than I think that I'm being dumb, I guess it's
better to find out now rather than after the rebuild is complete.
John Phillips in Hobart, Tasmania.
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