Your Projects

Following an exchange of secret documents (Richard gave me a copy of his original design notes) a few months ago, I've been attempting to make a two-part steam control valve. This is what Richard has in his Duchess allowing it to whistle while moving as well as when switching from forward to reverse. I hadn't really appreciated the tolerances involved - they are at the masochistic end of the spectrum.

Here is my progress so far. I have something that sort of works under compressed air, but there is a small steam leak to be cured. When running under steam, the leak reduces the available pressure resulting in a pitiful crawl at best.

The general concept is to add extra backlash in part of the control valve which allows an extra whistle passageway to be traversed as you go through the backlash. Some photos might help:

The normal spring holds the parts in place on the new shaft.

The new parts I had to make compared to the Hornby originals. The lower part of the new whistle has the extra backlash to allow the shaft to turn the top part while the lower part stays still. At least that's the theory.

The really tricky part now is to find out which path the steam is following as it leaks out of the whistle. Does anybody know a good way to look inside while at pressure ! Perhaps a glass superheater could be invented next.

Some more in another age when I've found enough time to move on a bit further.

David