Accurate Strong Gantry

[Ross77]

What spindle are you planning to use? I know there were a few mentioned but cant see which one you decided on.

The thing to remember with spindle bearings is the amount of pre-load they have which affects the rigidity and speed.

Taper bearings with a heavy preload will be super rigid and cut hard materials but will be limited to a low speed. If your milling steel this is what you need.

Angular contact (AC) bearings are similar and the heavier the preload the more rigid they become. Due to the reduced contact area they have a higher speed capability but lower load bearing capacity than a similar sized taper bearing.

So as most of the high rpm (15-20k) router spindles will be using AC bearings then the rigidity will probably be low. This will be the weak link and no matter how strong the machine is it wont be at its best.

Bottom line is you can have a machine capable of both but realistically you will need two separate spindles.

You could always get high end spindle with hydraulic adjustable preload :0)

I have 75x40 precision AC bearings for mine and should get me up to 12k for HSM with adjustable preload and with oil mist lubrication lol.