The spindle is the very core of every machining centre. Even though of major importance, spindle maintenance is an often overlooked or forgotten task. Every imperfection in its performance directly affects the quality of the final product. Taking care of the spindle therefore means caring for the outcome. Not only are the results affected by the working condition, but spindle malfunctions can also cause incidents ranging from expensive failures to severe accidents hurting staff. All tasks necessary to carry out the preventive maintenance of the spindle and the machining centre are documented in the Operation and Maintenance Manual provided by Okuma. Following the manual’s instructions ensures that the spindle’s life span will exceed Okuma’s three years warranty.
- Keep it sealed: Many spindle problems occur due to coolant leaking into the spindle. If the sealing is damaged, coolant may leak during high-pressure operations contaminating the taper. Therefore, checking and replacing the through the spindle coolant pin is key. In addition to the manual, every machine equipped with a through the spindle coolant pin has a maintenance schedule attached to the side of the machine.
- Keep it sleek: Even the best through the spindle coolant pin cannot work if the pull stud is damaged. In order to work properly with the pin, pull studs need to have a ground face and the through hole measurements need to be in accordance with the specifications listed in the Operations and Maintenance Manual. The pull stud’s face also needs to be free of abrasions, dents and scratches. Defective pull studs may not only cause coolant leaks but also severe damages and accidents.
- Keep it tight: Ensuring that nothing is leaking is always a good idea. Especially the top and rear of the spindle should be checked in order to make sure that the rotary unit is in good working order and that no fittings are leaking.
- Keep it smooth: The spindle lubrication tank should only contain the specific oil listed in section 3 of the Operations and Maintenance Manual. Only bearings that are lubricated with the right oil will seal reliably.
- Keep it breathing: Make sure that the spindle cooling unit air filter is clean and inspect it following the instruction of section 5 in the Operations and Maintenance Manual. Maintain the air panel filters following the steps listed in the same section. That way, the cooling oil will be cold enough to prevent overheating and the spindle will receive pure air to mix with the lubricant.