""no patient died untill today""

Untill today in our hands no patient died!  The sentence is very simple but this is the basic of our daily work.  Sometimes the patient will come twice and we have to find out the reason for this unwilling come back. We learned that most of our patients are coming back on behalf of a not propper done maintance job.  So we decided to assist the users of machine tools with some information how to prevent a spindle damage. 

 The rotary joint

The rotary joint is one of the most sensitive components of a motor spindle. The Spindle Doctor offers you a special service and bets on the proven laser lift slide ring technology for a longer service life. However, conventional rotary transmissions should be replaced after approx. 2,000 operating hours, since otherwise a serious mechanical breakdown might result .

Please note that the quality of your coolant significantly impairs the service life of your rotary transmission. The processing of special materials such as glass, ceramics and aluminium results in the release of suspended particles, which especially damages the ceramics of the rotary transmission and thus leads to a reduced service life. The occurrence of leakage is in many cases the beginning of the end and often leads to the total loss of the machine.

 Checking the filter fleece and the cooling lubricant

Please also make sure that the filter fleece of the band filter system is always located at 40 my and the cooling lubricant shows the right concentration and the desired pH value. Additionally, a police filter is a good supplement in order to assure the purity of the cooling lubricant.

 Regular cleanings

Of course, you should clean your machine on a regular basis. Especially the sensitive spindle cone should undergo this treatment. Please note that you do not spray the tool clamp with cleaning agent, but impregnate and clean the cone with a metal grease. The collet and the clamping set should be lubricated and protected on a regular Basis. The slot screen must also be cleaned in the case of too many chips. The cover plates must be dismounted every six months and the cast bodies, guidances and ball screws which are located behind must be cleaned. The same also applies to the tool magazine. Finally we recommend slightly lubricating the tool collet after approx. 250 operating hours.

Controlling the spindle oil and spindle lubrication

The use of an oil air lubrication can lead to an overlubrication or underlubrication of the spindle bearings. A regular control of the lubrication hoses and lubrication distributors is required in order to avoid bearing damages and failures. The oil level of the lubrication and the flow volume should also be monitored on a regular basis. Please note that a lot of tool machine manufacturers only monitor the filling level

but not the flow volume. The air quality, especially the purity of the used compressed air, must be constantly monitored and guaranteed. Polluted air or too-high air humidity are effective factors and result in the early failure of the spindle bearing.

 Spindle cooler and spindle cooling medium

The spindle cooling medium discharges the motor temperature via compressor cooling systems or heat exchangers. Please note that the cooling medium must always contain a sufficient portion of lubricants in order to protect from corrosion and contamination, therefore the filling level and the concentration of adaptives should be monitored on a regular basis. A permanent over-temperature can lead to an early failure of the spindle bearing. Therefore, please note that the system temperature of the spindle should not exceed 25 °C above the room temperature. The switch-off limits in the machine control are often defined at over 60 °C.

 Replace wear parts

Even a perfectly adjusted spindle causes wear. The pneumatic air filter and the hydraulic filter should be renewed at least every year. The hydraulic oil can be refilled in in this context. The fluid grease in the central lubrication must be renewed every two years while the wiper of the linear guidance must be checked and, if necessary, replaced every year. The same applies to the brushes of the tool flap. Please also include the coolant of the spindle into the programme of regular renewal as soon as the quantity and concentration no longer meet the specifications.

 Keep control cabinet doors shut

What sounds like a matter of fact is often neglected in practice. We urgently recommend always keeping the doors of your machine shut. Otherwise this might lead to failures of the electronics, for example due to penetrating dust. If you work with the ventilation mats, please replace them after 200 to 250 operating hours at the latest.

 Switch off the machine during non-use

Machine tools also need to call it a day. Therefore, please do not forget to switch off the machine completely during non-use. Of course this measure also helps you to save energy and thus cash.

 IMPORTANT

All maintenance and service measures should only be executed by trained and professional persons. Otherwise this might result in a risk of accident or a defect of the machine.

 Use suitable cleaning Agent

Please make sure to use the suitable material for all cleaning measures. Of course, compressed air tools and/or high-pressure cleaners are taboo and slightly linting cloths, such as cotton waste, should be avoided whenever possible.

Professional disposal of the lubricants

All substances which are renewed must be disposed of appropriately and professionally. This especially applies to oils, greases and lubricants

Note the instructions of the manufacturer

Different machines require different materials. Therefore, the instructions of the manufacturer must absolutely be observed. Especially oils, greases and lubricants show significant differences and also the values for the cycle cooling water are pinpointed.

Do you have any questions? Please don't hesitate to contact us.

 The Spindle Doctor is happy to support you with the professional maintenance and provides you with useful tips in order to keep your machine for a longer period of time.

Wolfgang Heinisch

alias The Spindle Doctor ( [email protected])