I have some questions related to my graduation 3-axis CNC machine project. Every answer and helpful comments are welcome. To introduce the project, we are working on making a 3-axis CNC milling machine. We ordered some parts, a 2.2 kW watercooled spindle with a matching inverter. The spindle is regulated from the VFD from min 8000 rpm to 24000 rpm. The dimensions are 80 mm in diameter and 200mm in lenght. 4 bearings in. The frequency is from 0-400 HZ. Also linear bearings,supported rails, ball screw set have been ordered. The working are is 210x297 (A4 paper). The tool should be moving in Y and Z direction while the support table should be moving in the X axis direction. X and Y are 300 mm in lenght and Z 250 mm. Still I'm trying to find all sorts of materials for this project, if you have something to recommend or link it would help a lot.
So, my questions are:
1. The goal is to be able to mill steel. But for steel milling the RPM should be at a much lover rate 1000 rpm e.g. So my general idea is to build in a planetary gear reductor or by building in pulleys and a belt. The torque should be higher while the RPM's are being dropped. What are your opinions on this? And, if the RPM's are being reduced more by VFD will the torque be enough to mill steel? Let's say an steel alloy AISI 1020.
2. How do i calculate heat generated in the spindle motor while on max load. (24000RPMs). I searched on the internet it says a 80W water pump should be enough to cool the spindle, but still I would like to calculate everything. And to simulate that which programm do you recommend?
3. And do you know any literature that can help? Does anyone have experience in building their own CNC? Any help is welcome.