Spindle bearing temperature

[paco]

Spindle expert,

what will most likely cause heat at the bearing(s); spindle RPM (high) or cutting force (thick/high chipload)?

I find that my spindle bearing get pretty hot under some circumstances and I was to start shopping for an infrared thermometer but what use will it be anyway?!... if I have to slow cutting specs. down to a router motor pace.

[br928]

Paco,

I am no expert, but just finished installing my 5HP Colombo recently.

I am getting more heat from the motor than the bearings. I use an inexpensive IR thermometer from Radio Shack, ~$20 I think. Motor housing is getting about 130-135 Deg F. The PDS Colombo tech said that that was normal but not to let it get over 140 Deg F. Heat from the motor will be transferred to the bearing and heat the bearing grease making it too thin. Man....a 5 Deg F raise in temperature can cause major problems.

I am beginning to miss the ol' Porter Cable. I can buy three of them for the price of a bearing change on the Colombo! Time will tell if it was worth it!

[carlcnc]

Stan,Paco,
I have a 6 year old and sometimes heavily used 5hp Colombo,
I don't think my case or bearings have ever approached 130 degrees. Not that I have ever used a thermometer,but it has alwasy been barely warm to the touch. Are you guys using a line reactor between the VFD and spindle?
Carl

[paco]

Nothing scientific here; under the shower I was thinking that it is getting warmer than me (37.5°C - 99.5°F) and hotter than I can stand for, say, 5-10 seconds but less than 60°C (140°F) (because my water heater shouldn't reach any more than 60°C or it would burn me - I can't stand the water coming from only the hot tap of my home faucets any more than a few seconds). In other word, it's probably reaching a temperature in between 40°C and 57C (104°F and 135°F).

quote:Are you guys using a line reactor between the VFD and spindle?No!.. not that I'm aware of looking at the wiring. It's a spindle/VFD bundle (all wired and prep.) from SB.

I didn't got any reply from HSD rep. yet (weeks... months?!). I could call the local repair shop but when you call a repair shop for an unknown problem, you unusually get a repair man/tech. with it's toolbox and an open bill!... still, I may take a chance.

I'd like to hear about other 4HP 220V (1 phase) HSD spindle owner if it's not too much to ask. Thanks in advance.

[harryball]

Paco, I'm running a 4HP HSD and I have an infrared thermometer. I've shot the temp various times in different places but I don't remember them off the top of my head but that's because I saw nothing alarming to me (like the 230 degrees on the steppers)

Where on the body do you want me to take temps and next time I run a batch of bat houses I'll take the temps there?

I do notice the spindle get's hot enough it's not pleasant to touch, but not painful to me. That may just mean you don't tollerate heat as well. I for one don't tollerate cold very well.

/RB

[Gary Campbell]

Paco...
Do you have 50 or 60 cycle per second power? 50 Htz power supply could cause some extra heat doing the same jobs we with 60 Htz power with ease.

We use the 4hp HSD and cut sometimes for hours pushing a 3/8 Mortise compression fairly hard. The spindle gets hot, but not as hot as our compressor motor, which runs shorter time.
Gary

[harold_weber]

Gary, please help me understand how 50Hz power can make a difference? Doesn't the power first go to a VFD? The VFD converts the power into Direct Current, and then its converted back to AC at the frequency you set. So the spindle never sees 50Hz AC current. My VFD's are rated at full power for any input frequency between 50 to 60 Hz.

[Gary Campbell]

Harold...
This is an assumption I made based on specs from most 50/60 Htz motors. Since most are listed as having less power output (HP) at 50 Htz than 60, I assumed that the spindle/VFD combo would act the same. Hopefully, someone with real knowledge can chime in and either confirm or shoot down my guess.
Gary

[harold_weber]

Sure, a 50/60Hz induction motor (like what's on a typical table saw) will run slower on 50Hz and therefore make less power. But this is a different situation. With a VFD you get to set the frequency of the power going to the spindle, so its speed is independent of the input frequency to the VFD.

So now we are left with the question of whether or not the VFD can provide the same power at 50 Hz input frequency. I have Hitachi VFD's and their specification sheets says they provide the same power output at 50 to 60Hz input frequency. Does anyone have a different brand of VFD whose specification sheet says it doesn't provide full power at 50Hz?

Finally, this is not doing Paco any good, because Canada has 60 Hz power according to this source:

http://en.wikipedia.org/wiki/Mains_power_systems

[Gary Campbell]

Harold..
Thanks for the clarification. It looks like we have to wait til Paco has a reliable means to measure if he has a heating problem. I am sure hoping he doesnt, as our PRSa can put a much higher load on the spindle than a PRT.
Gary