Good evening All
Once again I'm in need of help!

I'm looking for a VFD for a cnc lathe conversion and I'm looking for the best one (and cheapest) for the job. I will be threading so either need a closed loop vfd or a sensor less vfd that can hold constant speed under load.

The dedicated closed loop ones are a bit pricey so I'm looking for advice as to whether I need a full blown closed loop system? the motor and drive will be 3hp so should have plenty of power.

I've seen these inverters which are sensor less but in the manual they say it can be configured for PID. is that not then closed loop? this would seem like a good option as I could switch to closed loop if problems arose.

I've read it a few times and does seem to be capable of closed loop but not sure why its not advertised as closed loop.

Thanks in advance