An expensive lesson that some wheel repair shops learned too late is that the automatic oil system on the CNC lathe may not be really fully functional all the time due to lack of maintenance. Many operators simply assume all is well if the alarm does not go off.  When the oil level is not really low for a long time, the automatic oil system has stopped working without the notice. In that case, the surfaces of the machine bedways become very dry and eventually causing the poor finishes on the machined wheel surfaces as shown in above pictures for Wheel Sample #1 to #3. These noticeable poor finishes were caused by the lack of oil lubrication on bedways. 

For this reason, it is very important to check the automatic oiler once a week for its normal function as part of the maintenance. The simple test to verify the function of the automatic oil system is to turn the timer onto the continuous mode (0 minute) for a couple of minutes. Then, you can check on the bedways for really fresh oil drops coming from auto oil system. If YES, then, that is working well.