To VFD or Rotary Phase converter

I’ve built two rotary converters, a 5hp in garage for the mill and 3 hp in basement for EMCO lathe . I have a total of maybe $100 in both including the motors, relays for starting, and balance/run caps. The lathe had a two speed motor and it wouldn’t work well with a vfd. Vfd is great for speed control but one rotary can run a whole shop.