Hi im trying to build a cupola furnace. ive seen some sort of plans on "backyard metal casting" website but the furnaces that were built didn't seem to work right. 

Im hoping someone here has plans of a working cupola furnace. Id like to build a small one say 6 to 10 inch  size id. hope you can help thanks! 

I, and no doubt others, would suggest that the backyard metal casting site is the place to pose this question. If their forum can't provide you with appropriate guidance........