Originally Posted by cjjonesarmory  After running my NM200 at about 3100 RPM for one hour or so under light load, my infrared temp probe reads about 140 Degrees F or so. After about 2 hours, it gets to be about 155 or so. I shut it down when it hits 160 because I get nervous. The location where the highest temp is found is on milling head (have to take off the shroud), closest to the arbor.
I had one bearing already go out in the spindle, which I have since replaced. The first bearing was contaminated with metal shavings and fibers. I believe the contamination was most likely present at the factory when it was assembled. It also had almost no lubrication, but it's possible that the lube burned off under the high temp of the failing bearing.
SO it's the chicken and the egg dilema. Did the heat burn off the lube and cause the failure which caused the metal shavings?
OR
Was the metal contamination the initial culpret causing wear, heat, etc...
To make a long story short, I wanted to know what normal operating temperature is for a spindle (and bearings)? My new bearings are in place (replaced them all) and I am reading similar temps.
Thoughts anyone? |
spindles get hot normally, but im not sure if 160 is normal. my nm070 spindle after an hour is hot to the touch, but not so much i cant keep my hand on it. a guess would be 140-160f.
part of this heat comes from the tool friction, part from bearing friction. i dont have any strong airflow in my enclosure though, so it could probably be alot cooler.
i dont think 160f is hot enough to harm the grease in the spindle bearings, but you should lube it regularly anyway methinks.