I bought a very lightly used NM-135 v2.1(?) about a year ago. I've gotten a lot of use of out of it so far, but I'm wondering about what general maintenance should, or can be performed on it. Aside from the self contained oiler, is there any other lubrication points I should manually look into? Specifically the spindle bearings? I run it at full spindle speed (6k rpms? I've seen conflicting info on whether or not it's 6k, or really 4.5k? Although it displays 6k in Mach 3)... I started feeling the spindle housing and after about 2 to 3 hours of running with the only down time in between running is just long enough to swap another part into the machine, it starts to get "burning hot" to the touch on the outside of the machine. I started giving it a 1-2 hour break every 2-3 hours of run time to cool down. I'm probably working it a lot harder than I should be.

I'm just wondering, is there something I should be lubricating periodically that I'm not? Any recommended maintenance that should be performed aside from cleaning, and using the oiler on a regular basis?