This is my attempt to replicate a volume knob for a Tandy 1000 TL/2 computer, though it also works with other Tandy 1000 computers. The factory knob had fins behind the handle, but those were non-visible once the knob is installed, so I deleted them in order to provide more gluing area.

A raft is fine for this, but supports should not be needed. Print the three pieces. Then glue the two halves together, and then glue the cap onto it. At that point, it should work exactly like the factory knob on a Tandy 1000.