First loco build

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Steamup

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I am new to this game by the standards of the guys on this site so I am looking for some advice.
I enjoy making steam launches which have provided me with the opportunity to develop a new passion for steam.
I purchased a set of castings for Heilan lassie 3 1/2" gauge locomotive some time ago with a vague intention of building some time in the future.
That time has arrived I think.
I have slide valve cylinder castings and piston cylinder castings for this loco. Which way do I go?
Mark
 

deverett

deverett
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Mark

As this is your first loco and you already have the castings, why not follow LBSC's 'Words & Music'? Many of this design have been built and run successfully following same.

Don't know whether the design is for slide or piston valves, though.

Dave
The Emerald Isle
 

abby

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Mark if this is your first engine I would go for slide valves as they are less demanding for accuracy , also the adage " piston valves wear out , slide valves wear in " is very true.
When you have completed the locomotive and had some fun running it you could machine up the piston valve cylinders and retro-fit them.
Dan.
 

GWRdriver

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The answer is "it depends." The slide valve version will be a bit easier to make and over time be more steam-tight and require less maintenance (or be easier to maintain.) However since the full size loco (or the full size loco this model approximates) was piston valved, the piston valves would help it better represent the prototype. Someone could also make the argument that piston valves give better valve events and steam distribution and therefore performance. Maybe so, maybe not. Here are pictures of the two versions (courtesy Station Road Steam web site) which show the differences in the external appearance of the cylinder blocks.

Heilan1.jpg


Heilan2.jpg
 

Steamup

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Thanks for the response thus far .I have experience of slide valves but not piston. By the way both of the photos seem to be piston cylinders.
 

GWRdriver

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The top one is slide valve. The valve chest cover and screws can just be made out and if you look closely you can see the parting line between the cylinder block and the valve chest. But I also know this from another indicator, for slide valves (outside admission) the radius rod connects to the combination lever below the valve stem and for piston valves (inside admission) it connects to the combination lever above the valve stem.
 
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GWRdriver

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steep learning curve.
Yes, and will never end (unless I decide to end it.) Coming soon I must design an outside admission Walschearts valve gear from scratch and there are something like 57 potential variables in such a gear. Talk about learning curve! Certainly many of them are predetermined but even with the best texts and newer computer aids setting the rest of them is like juggling cats. :wall:
 
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