I see this is commonly done on machinery which (I think) was originally run from a master line-shaft system. I'm enclosing a picture of Wildo's 9A restoration as an example; my Diamond mill has a similar setup. How does the belt stay on if the large pulley isn't crowned? Would a serpentine or leather flat belt be a better choice, and the motor pulley changed over to a flat one (with a crown)? Mark S.