Have been attempting exactly what you have for the last six months!!
A source of diecast single V pulleys is :
I have managed to obtain a 14mm machine reamer from E-bay which will take the 1/2" bore out to 14mm.
But again as in your case my lathe is not yet running -- is it?? I will probably stick an old 1/2" shaft motor on it temporarily to ream out the new pulley.
Cheers, Paul
I need a pulley for a 1/2hp motor with a 14mm shaft with key. Ideally it
> would be 3 1/4" outside diameter, but anything from 3" to 4" would do. I
> guess I could cut the keyway myself if necessary.
> Can anyone suggest a source for this at low cost?