The thread has had a "gutter" added between the last thread and the shoulder of the hub as a "machine/tool exit" as a spring with a ground end is being screwed onto it but I have been told its too fine to try to get the thread up to the very end of the hubs shoulder.

As for 1 operational pass Im not sure, but Id like to keep the holes uniform across all the production if possible

As for numbers Im looking at setting up shop in the US as supply chain issues out of asia is ridiculous (freight more than anything due to FJB insane fuel prices means small jobs are now no longer economical 

So Im trying to figure what machinery I need (second hand to start) to get this going here

Try this IGES file of an older version 

TSC06-02 Keyway.iges

Ive been told only a 5 axis machine will do the job

Needs a helix machined to accept 3 spring coils (screwed on, so it needs to be machined precisely)

So width ranges (3 models) 48mm, 70mm &  81mm

Currently made of either 4140 or T6061 T6 (customers choice)

Hole from the top to accept a 1-2" shaft also

Any model recommendation would be appreciated