This is not a CNC specific question, but rather a Weihong NK105G2 specific question.
Answer: RTFM.
Find out what connection options and protocols it supports and then follow them.
I have read the manual tbh and there is nothing specific on that matter, that is why i decided to ask here.
The machine works just fine with usb flash, but connected to the PC with usb cable literally nothing happens, like it is not connected at all. Anyway thank you for the answers i assume that nobody here has any exp with this particular chines machine which is no surprise tbh.
Also excuse me is this is the wrong subforum
USB is a master / slave protocol. You can't connect 2 masters to each other and expect it to work. That's why USB cables don't look the same on both ends.
Plugging a USB memory stick into the computer, the computer is master, drive is slave and acts as a mass storage device. Same when you plug the memory stick into the CNC controller. If you want the CNC machine to see files on the PC you can't just hook it up with a USB cable, since the PC won't just act as a storage device. Mobile phones are a special case, they usually act as a slave when connected, but some have USB OTG which allows them to act as master so you can plug in a keyboard / mouse / memory stick, etc as slave.
Unless the NK105G2 has a USB-B socket, MiniUSB or MicroUSB I don't think you can hook it directly to a PC with USB. Are there any other ports on it?
You may just have to live with using a memory stick or other external storage and switching it between the PC and CNC to transfer the designs.