We have problem with spindle motor that cuts out and knocks all feeds out as well, (its as if emergency stop has been hit)this usuallly happens after about 3 hours from switching on. When we switch off for 1 hour and then back on it will run for about 2hrs. We think it could be spindle temp cut out thats causing this, anyone got any solutions.
Make sure phasing is correct and the fan at the bottom of the spindle motor is blowing UP and not fighting a natural chimney of hot air rising.
When the brushes get short on the spindle motor it cannot conduct current through the armature and the revs drop under load. If the control sees a reduction of 20% of commanded spindle speed it stops the feed untill revs come back up.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)