Thanks JMirisola, but how would I figure out the inner and outer diameters for the washer config if I only know the dimensions of the formed funnel? Say if the washer's inner and outer diamters are 3" and 4" respectively, that would leave a 1" width of material across both sides of the washer...
How would you go about creating a flat pattern for a funnel with the top 2/3rds cut off? I know you to make one by rolling the sheetmetal and then "welding" the ends together but how would you do it for if you wanted to form it from a washer shape as the base material? In essence you are almost...