SLF FS45-50 Spindle Repair

This style of SLF spindle is commonly used in smaller milling machines or specialized operations that need higher speed capabilities. The downside to this type of spindle is it’s lack of power and rigidity.  The common failure modes are overloaded bearings, bent shafts, overloaded stators and contamination. If the spindle is run within its specified range of capabilities they tend to last quite well.


We completed a full breakdown and evaluation of this SLF FS45-50 spindle when it arrived at Northland Tool and Electronics.  We noted that the #1 front bearing was failing due to a slight contamination.  We also measure that the shaft taper had 6 microns of runout.  No other dimensional deviations were noted for the repair.



The following actions were performed on this SLF FS45-50 spindle:

  • Clean, inspect overall dimensions
  • Kiss grind the taper
  • Replace bearings, o-rings, and assembly screws



After reassembly of all components, adjusting bearing preload, and undergoing break-in and testing procedures, this spindle passed our final quality inspection before being returned to our customer with a 1-year warranty.

Does your spindle need repair? GET A QUOTE TODAY