First, I'm not a mechanical engineer, just some other kind (EE), with a one-time mechanical problem. I need to find a way to make a steel cone, with a thin wall section, like in a funnel. The problem is that the size at the small end is too small for any sheet metal roller I have ever seen, else this would be easy. The cone is destined to go on the tapered end of a crankshaft driving a generator, which is direct coupled to the tapered shaft. I need to adjust the spacing between the engine and generator housing so that the far end of the generator's rotor shaft is in the right place. Currently tightening the long bolt through the rotor pulls the outer support bearing partly out of the end housing supporting it, and misaligns the brushes/rotor. I considered machining the housing on the engine, but numbers are not working out. It looks like there would be a "break through" of some thin casting sections if I cut out .100" to move the generator into correct "Z" depth. So, anyone have a suggestion for how to make said thin funnel shape? wall thickness needs to be .010", very tight tolerance, as the taper is1-to-5 on the shafts.
TIA, Bill ps: hi-tech approaches are not economically feasible..