At 10:48 AM 8/16/01 -0700, you wrote:
>I intend to buy Lady Anne from Roundhouse.
>I would prefer her with an inside frame . . . . .
>Has anyone experience with these modifications
Matthias,
Although it certainly could be done, I doubt the cost could be
justified. Everything from the top of the chassis down would have to be
redone to convert to inside frames.
>What are the parts of a slide valve and piston valve, how do they work?
There are too many parts to go into here, for instance the Walschaerts
gear (a variation of which the Lady Anne has) has no less than 49 variable
points/values in the cylinders and chassis. There have been countless
publications on the subject of valve gears in the last 150 years, ranging
from a few pages to volumes as thick as my forearm and a few of them have
been written specifcally on designing valve gears for model engines.
Most valve gears have the same purpose, to derive the motion to drive
the valves from the cranlkshaft and there are dozens of valve gear designs
and any one of them can drive either a piston or slide valve. Whether or
not piston valves are superior to slide valves or vice versa is
conditional, each has its place, based upon size and application. But
generally speaking in miniature practice, especially as the scale gets
smaller (and we're near the bottom), slide valves are preferrable (although
not necessarily superior) to piston valves because they are simpler to make
and keep steam tight.
>seals. Is there anywhere information on the web
>(descriptions, drawings, etc.)?
For starters try this site: <http://www.tcsn.net/charlied/> This will
show overall animated illustrations of all the better known motions. For
specific descriptions and details of the valves themselves you'll need to
find texts or magazine articles and if you have a decent public library or
university you ought to be able to find information there. You can of
course go to <www.google.com> and type in "locomotive valve gears" and sort
through the 1000's of entries that come up, most of which will refere to
books and publications.
Regards,
Harry Wade
Nashville, Tn
