Porta N145 FMU Spindle Rebuild

Jesse Riccardi General Manager

Possible cause of failure:
Spindle arrived seized, missing the drawbar assembly.
Spindle bearings failed from coolant contamination, grease was washed out and full of rust.
Front quill wiper seal was worn out and broken allowing contaminants to wear and score the quill od surface.
Quill od measures -7/-35 on the worn area.
Shaft tooling taper has severe gauling.
Ball screw bearing journal is fretted and undersized by -12/-14 (iso is +/-4).

Recommended action:
Clean, inspect overall dimensions.
Replace bearings, seals, balls and orings.
Grind, chrome plate and finish grind the taper.
Grind, chrome plate and finish grind the 75mm on ball screw.
Grind, chrome plate and finish grind the 145mm quill od.
Adjust preload, balance, assemble and break in. Final quality control inspection.

Jesse Riccardi General Manager

With over 15 years of spindle rebuilding experience, training, and shop management, Jesse specializes in partnering with industry leaders to advance and improve the precision machine service market.