(NEED YOUR HELP SOOO MUCH!)
Hello guys,
in couple of month i want to start build an "fixed gantry" CNC router for machining steel and aluminium and use LinuxCNC. The machine should later be used for comercial use, so it should be an strong machine with ATC, etc..

Unfortunately i no experience at all. I have started to read about CNC and machining about one and half month ago, but many hours a day. I dont want talk here about the design, or rigidity or anything else, because to be honest, currently i see there no problem and i have a much bigger problem where i am already stuck for an week. I have watched many videos and it doesnt matter any more what i write in google, all links are already marked as "clicked".
So, i just want to say that tryed everything to get the information by my own and opening an thread and ask you guys, was really the last option. Unfortunaley, now i really need your help.

My idea/plan:
For cutting steel and aluminium without any problems i need lower rpm/much torque for steel and higher rpm for aluminium. I looked over an week for an spindle motor on aliexpress and also on U.S and EU sites, but the most spindle motors are from 9.000 - 18.000 rpm or 12.000 to 24.000 rpm. I have watched for spindle motors from 1000€, and at least over 3kw (mostly over 5kw), so not for the cheap ones. After some time i thought its an good idea to buy an Belt drive spindle and connect it to an standard electric 5.5 kw motor with 3000rpm with 2 different ratios, but i would lose much torque on higher RPMs, so i came to the idea to use an special spindle motor.

In germany i found an good condition Fanuc AC (servo)Spindle motor "3S-12000" for 550€. Its from 1995 with an red cap. Here the link to the spindle motor, where are all informations: https://www.resale.de/Gebrauchtmasch.../72522159.html . Soon i will visit my family in Germany, so i could buy it already and pick it up up on the way, but i just dont know how i can use that spindle on an new system. The parameters are just perfect for my idea, because of the power, torque (over 20nm) and of course the RPM (1.500 - 12.000). I want to connect the spindle motor to an belt drive spindle (ATC BT30 - max 12.000 rpm - about 1000$) through an chain or some strong quality belt.

So, its important to have ATC and also be able to do rigid tapping and everything what can be done with this kind of spindle motor.

Like i wrote already, i have tryed to do my homework and looked for the parts i need by my own, but mostly i found forum threads where poeple have asked for retrofiting an old lathe or mill where are this kind of spindle motors where poeple wrote to use MESA cards etc?!.

Im not sure, but do i need an "7I77 Analog servo interface plus I/O daughtercard" with "5I25 Superport FPGA based PCI Anything I/O card" ?

I have at all no idea what i need to be honest, but im so stuck with that. Since over an week i have installed Solidworks and have bought an book, so i can start to learn and draw the project, but i need to know if i can use that kind of spindle motor and what parts i need.

It would be really very helpful if someone could tell me exactly what parts i need. I just dont want to loose more time, because since 3-4 days, i have the idea with the spindle motor and im doing nothing else then trying to find out how its possible to use it.

Please guys, help me...

Best regards,
Denis