I bought one of the infamous Chinese spindles some 2 years ago and used it happily since (knock on wood) although the bearings made more noise from the very beginning when spinning by hand than I like. It has now probably some 200-300 hours of use, normally 12,000 to 15,000 rpm, sometimes 18,000, rarely higher. Mostly small bit wood duty but occasionally I machined brass and mild steel.
By chance I read somewhere that spindles are supposed to be heated up for 5-10 minutes with increasing rpm before use and, googling I found it seems to be quite a common recommendation. I never did that and the highly qualified Chinese seller did not tell me.
Now, should I change habits? What happens if I dont pre-run the spindle before use? Is it only about accuracy for precision mills and I can not care less for my router or is it a bearing wear risk? Thanks for any enlightenment.
JB