Dont fix whats not broke. Motors do get hot. Can you put your hand on it? If fan is working, and machine is working ok I wouldnt worry about it.
I’m a huge proponent of not fixing what’s not broke, but something seems off here. I can’t hold my hand on it for more than a moment. It’s hot.
We see about 35-50 degrees centigrade during normal operation. Our machines alarm out if any servo motor reaches 100 and I believe the warnings start at 80. I would definitely be looking into the cause of a motor constantly running 90*. We have only had them get that hot when there was a significant issue. The one I can remember right now was one of the two ball screws on an axis fell apart and the remaining servo had to handle the whole load. It could do it, but struggled.
Do you have any way to see the loading on the servos?
I saw temps of 96 C today and no alarms. Maybe if it hits 100, it’ll alarm out. I feel like a really hot day in the shop, and I’ll find out. The load meters aren’t showing anything that’s out of the ordinary.
I checked the servos and spindle motors on my Nakamura TW-10 at the end of the day with a hand held thermometer and every thing is under 35C. 90C sounds really hot.
Something is going on here. Have you checked if the controller temps vs a hand held corroborate?
I checked with an IR thermometer on the motor housing and was getting a max temp of 82 C while the diagnostic was showing 92. I’d say that those two temps are close enough to corroborate.
I checked some of the other machines, and the highest temp I saw was 68 C. The other turning spindle of this machine is only at 48. I’m really not doing any turning with this second spindle, though, other than grabbing the part when it gets cut off.
Something kind of weird that I did notice is that the temperature fluctuates with the machining cycle. The part I’m making has a cycle time of about 3.5 minutes. About the first half of that time is turning, then the rest is milling, cross drilling, cross tapping, etc. When the milling starts, the temperature starts creeping up. Then, once it goes back to turning, the temp drops. Today, for example, I watched it go up to 96 for the milling, then drop down to 92 for the turning. It does this repeatedly for every cycle. I don’t know how much of a lag between the heating of the motor and the reading of the temp sensor there is, so I can’t say for sure if it’s really the milling that causes more heat on the motor than the turning.
Like I said, the motor fan is working. I’m wondering if the vents through the motor housing might be clogged.
By the way, it seems that machines with Fanuc 18i-TB and 21i-TB (and probably newer) have these temp diagnostics if anyone else is interested in monitoring their machines. It seems like it could be a good preventative maintenance tool. 18i-TA and older don’t seem to have it.