Runner:- The runner is the path by which the molten metal travels and fills the mould cavity. The molten metal comes through the sprue. Riser:- The riser act as an reservoir of molten metal. It feed the molten metal to the mould, after pouring. It helps to compulsate the shrinkage. It...

You can really do any size, any metal, and any level of detail. It all depends on the type of sand you choose, the type of casting you’ve picked, and the heat you use. For smaller things, such as bakeware, dumbell,  I would tell you to use a Lost-Material casting, which is to use a materi...