The vertical alignment on the spindle signifies that metal chips can accumulate to the surface area from the workpiece and have to be cleared. With regards to machining centers, there are several varieties of machine centers that cater to different manufacturing needs. 1 common variety may be the Vertical Machining Center (VMC), https://isocialfans.com/story4139271/helping-the-others-realize-the-advantages-of-horizontal-cnc-production