10 Inconvenient Mini Mill Truths 08 07 2017· The mini mill uses deep groove bearings—but for milling—angular contact or taper bearings are much better in combo loading radial axial Spindle Taper Stock Deep Groove Bearings Angular Bearing Upgrade New Bearing Break in recommended process R8 • 6206 2RS 30 mm X 62mm X 16 mm Top Bearing • 6007 2RS 35mm X 62mm X 14 mm Bottom