it depends on the type of running you require, an engine doing hard work, or a demo under steam. Just have a go with a small boiler, you will be surprised by the result I would bet. doing a large boiler is a hudge investement, a long job without using your lathe or and mill, too sad...
[ame]https://www.youtube.com/watch?v=KDjY2zIFZfE[/ame]
the engine I did here is the well known ET Westbury Vulcan, ( 7/8" Bore x 2 1/4" Stroke ) Don't look at the wobbling flywheel, it is fixed now...
[ame]https://www.youtube.com/watch?v=KDjY2zIFZfE[/ame]
the engine I did here is the well known ET Westbury Vulcan, ( 7/8" Bore x 2 1/4" Stroke ) Don't look at the wobbling flywheel, it is fixed now...