No worries on the english. It really isn’t a matter of ‘RPM that the system can handle’, it’s more with regard to how powerful a motor can it handle. I’ve only tested it out on my 2.5hp treadmill motor that I use in my lathe. I limit the duty on my controller to no more than 75%, so at peak it has handled ~1.8kW without issue. Now, my treadmill motor as is can go 6,000 RPM, but I’m interested in torque and lower speed on my lathe, so I have 2 reduction pulleys which brings my overall RPM down to a maximum of 1,500 RPM.

Basically, as the controller / driver is setup in the project files, it’s capable of driving a motor at ~160VDC ( rectified 120VAC ) @ 15A, or ~2.4kW. A fellow in the UK has updated some of the components in my design to work off of 220VAC, though the motor required less current to do the same work, and the overall power required was about the same.

Cheers,
Morgan