Our technical engineers retrofit Lenze inverter to CNC milling machine

The milling machine before the retrofit

Our technical service engineers were asked to retrofit a spindle inverter on an #Okuma horizontal CNC milling machine at a large engineering company.

The machine dates from the 1980s and we received the enquiry as a spindle motor repair – but with no fault found, the machine's inverter was diagnosed to be the issue. The inverter had undergone several repair attempts prior to our involvement, so a retrofit was decided.

After reverse engineering the machine’s electrical drawing, we found that a 37kW #Lenze i550 frequency inverter could be integrated. 

An encoder was retrofitted to the motor, in place of a bespoke resolver to provide closed loop speed feedback for precise speed control.

The milling machine after the retrofit.