Troubleshooting Fanuc Spindle Drives

A guide too troubleshooting Fanuc spindle drives: why do spindle drives fail?

A critical part of the make up of any CNC machine tool that requires a spindle drive. Troubleshooting Fanuc spindle drives is useful knowledge if you have a lathe, machining center, CNC punch or grinder amongst others.

When the Fanuc spindle drive faults it can cause multiple problems. Causing obvious machine downtime to potentially impacting the entire productivity of the business. Either requiring a replacement fanuc spindle drive or FAST repair turnaround.

Like any part within a CNC machine tool; Fanuc spindle drives do experience various faults caused by dirt, component failure, electrical faults, mechanical issues, climate problems, lack of maintanence and age.

Please make sure that all the obvious have been checked i.e. cables are connected properly, windings are good on spindle motor and no mechanical binding!

Alarms, Problems, Causes:

• Dirt: crud from the machining process such as coolant and other oils cover the spindle amplifier and smother it. Eventually can’t cool down forcing overheating at best a simple blow out; at worst a complete burn out such as fire.
• Component Failure: The most common cause is usually overheating, age, overuse. Components fail include power transistors, fuses, internal and external fans, isolation amplifiers, capacitors, resistors, current detectors and much more.
• Electrical Faults: commonly spikes, power surges; normally take out the breakers to the factory or the machine. More sensitive components on spindle drives can be percetible to electrical disturbance. Another is during maintanence tasks, machine moves, etc that cables are incorrectly fitted and can damage spindle modules.
• Mechanical issues: commonly internal and external fans fail causing the drive to overheat with components burning out. Other problems as mentioned above is problems with the spindle motor damaging the spindle drive. More common with older AC spindle servo units.
• Climate Problems: commonly too cold and moist or too hot. As with all electronics, they have effective operating tempreture’s and when the weather or environment surrounding the machine tool is either too cold and damp or too warm then components fail on switch on.
• Lack of Maintenance: Common issues are blowouts and component failures due to not keeping the spindle drive clean. Replacing parts such as fans as soon as they get noisy to prevent the module overheating.
• Age: As mentioned at the top all Fanuc spindle drives will eventually fail due to age; quicker if used 24/7 or allowed to get very dirty preventing heat exhausting from the circuits. All components whether logic or power have a usuable life.

Fanuc Spindle Drive Repair and Parts Services:

Keeping the drive as clean as possible, in an environment that is neither too cold, damp or hot is the best approach for preventive maintenenace. We appreciate this isn’t always possible!

With all of the fault and alarm issues addressed some are easier to deal with than others. However once the spindle drive or amplifier module has alarmed and faulted out and been proven too be at fault then its requires technical knowledge and expertise.

CNC repaired thousands of Fanuc spindle drives as Fanuc drive specialists. Capable of repairing spindle units from the early AC upto the latest ALPHA i and everything inbetween. Massive stock of spindle drives and amplifier modules ready to ship!

Contact us at +1 (434)971-1394 or email or fill in contact form(s) on the website. Alternatively consult alarm information for fault codes on spindle drives.

Troubleshooting Fanuc spindle drives (Alarm information)

• Fanuc AC Spindle servo unit
• Fanuc spindle amplifier module (ALPHA and ALPHA i)
• Fanuc biSVSP mutli axis with built in spindle (BETA i)
• Common alarms for Spindle drives
  • Alarm 12: Overcurrent / high current alarm (make sure not cables or spindle motor).
  • Alarm 31: Motor does not rotate as commanded

For more information on Fanuc spindle alarms see Fanuc’s own troubleshooting guide.

Different Fanuc Spindle Drive series and types:

• Fanuc AC spindle servo unit
• Fanuc SPM spindle power module (Alpha)
• Fanuc aiSP spindle amplifier modules (Alpha i)
• Fanuc biSVSP spindle unt (Beta i)

For more information about what CNC can offer for your faulty Fanuc spindle drives contact us on +1 (434)971-1394 or email or use one of the contact forms on the website.