Air Cooled Spindle

There seems to be a lot of discussions about spindles, when can we get our own forum category?

Second, an update on the installation of our air-cooled spindle. It’s all configured and I ran it for a little over an hour and a half today. The carving, shown in the photograph, was made using a tapered ball end mill with a .0325 radius end. The job was run at 16,000 rpm a rough climb cut at 25 inches per minute and a finish pass at 10 pm. The ambient temperature of my shop was 81 degrees. I monitored the spindle motor frequently during the carving, taking temperature readings with a laser thermometer. The highest readings were 87.6 degrees, taken at the lower bearing area, 89.3 in the spindle body’s middle area, and 83.4 at the top bearing area.

My son and I are very happy with these initial results. We realize that this job did not put a heavy load on the spindle, that test will come soon. But, we are happy with the thermal performance of the air-cooled spindle and glad we took that approach.

Also worthy of note that the trim router had .007-inch runout when measured at the tool, where the new spindle has less than .001 and that measurement was taken with the cheap collet that came with the spindle. I will need to redo the test with a collet the better grade set we purchased.

One last comment. This spindle is so quiet, that I’m thinking about how I can move my vacuum dust collector into another room.


Air-cooled spindles work for most applications just fine. Some have mentioned the downside is the air they blow down but with a dust boot that is not really an issue. I am very happy with mine.

Great to hear which one did you get mind sharing link thanks