LinuxCNC and Linux MX on different partitions

Hey guys

I would like to have both OS on my hard disk. My idea was to have 2 partitions so that I can choose the OS on start up.

But actually I have no idea how exactly to do it.
I tried first by making the partitions, than installed MX and later on CNC. But it does not work. 

 

Install LinuxCNC first, then MX.
MX should know how to use existing stuff, it can also be done on Debian but not easily.

I also tried. I created a live USB Stick with the MX ISO, but when I boot the stick isn't detected. Any ideas???

Plenty,
use win32disk imager to write the MX ISO to usb.

LinuxCNC isn't an OS. LinuxCNC is an application.
Have you considered installing LinuxCNC on Linux MX?

Yes, that's right. But I thought it would be best to use the complete offered Debian OS with LinuxCNC. I don't want make any compromise if there would be any details or options in MX that might influence the performance of the CNC.

Today I tried installing Debian with LinuxCNC first and than MX. Works fine now. But I need to take a look at the grub. That's not what I imagined...