Parallel Motor Rotary Phase Converter Help

Need to double my rotary phase converter output and have a few questions.

First motor can be used to start the second?
Do the two motors have to be exactly the same size/HP, RPM, etc.?
I would like/need to have second single phase supply for second motor?

I only need the added capacity for one machine and so most of the time I can use just one?
Sizing run capacitors for added motor?

Any help is greatly appreciated.

You really just need an unloaded 3 phase motor of suitable size (can be the motor on a machine that is not in use) . No necessity for more capacitors, no need for any extra single phase stuff, no start caps etc.

Start main converter, start the secondary idler from that, and start your load.

My existing RPC is a 30hp and the single phase feed is sized accordingly.

When I add in another 30hp RPC, I need to double the single phase feed?

Currently running 60amp feed to existing RPC.

I need to run 120 amps to both or 60amp to each?

The easiest for me is to bring another 60 amp lead from the 200amp service direct to second RPC and when the two units are combined there will be a combined 60hp and 120amp capacity?

I keep hearing about just adding additional 3 phase motors in parallel or idling more 3 phase machine motors.

If I need 60hp three phase I need single phase feed capacity for 60hp, adding more idling motors pulling from the same single phase feed will not work?

The 60hp total RPC capacity is for running 35hp cnc lathe.

Am I missing something here?

You can even use existing machinery as your idler, so long as it can run unloaded. Start your mill and lathe for a little extra help starting your compressor, for example.