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

[harryball]

I ran my 4 HP HSD all day today, continuously from 30 to 50 minutes per sheet, maybe 5 to 10 minutes between sheets. The highest temps I saw anywhere on the spindle was 131 degrees F on the side of the body. The black round base was about 120 degrees.

/RB

[br928]

Carl,

I am not using a line reactor between the VFD and spindle. Does Colombo recommend using one? The tech I spoke with never mentioned it. The little I have been able to find on the subject says it will reduce the motor heating.

[paco]

Thanks Robert. Is it on the 220V 1 phase? Gary, what about you?

[carlcnc]

Stan,
I don't know positively if the line reactor helps with motor heating,was just an assumption
I have read conflicting info on when/if one should be used but have always had one on my spindles.
You can usually find one or two on ebay,

good luck

Carl

[Gary Campbell]

Paco...
I am using the OEM setup on the HSD 4hp right from ShopBot. No Problems or even minor concerns with heat and our shop is often 90+ degrees during the summer months.

Have you put an IR thermometer on the spindle? We have many tools/motors that get very hot with use. If you are at or above mfgr specs, you may want to contact the mfgr for fixes.

Order a new machine yet?
Gary

[paco]

Shopping for one on Ebay... IR thermometer that is...

Not ready for another Bot here... I'm amazing myself at how I can achieve efficiency with only one! I'm seriously considering milling metal sometime...

[harryball]

This is the one I bought. I've been very happy with it.

http://www.instrumart.com/Product.aspx?ProductID=10228&Redirect=infrared

[Gary Campbell]

Paco...
I forgot to mention... yes, 220V 1Ph
Gary

[br928]

RadioShack

http://www.radioshack.com/sm-non-contact-infrared-thermometer--pi-2103171.html

[rhfurniture]

Paco,
Have you checked the amp output on the VFD? I can switch my (Hitachi) VFD to display amps instead of Hz and you will probably be able to do the same. I have set up a meter on the outside of the box housing my VFD to display this and find it very useful. Remember that spindles seem to be rated for 60 percent duty. My spindle never gets more than warm, but then I have one of those old fashioned ones with a fan fixed to the top of the shaft. I like it actually - sounds a bit like a jet turbine - very cool! At least you know that while it is running it is cooling, and the faster it runs the more cooling it is getting. Downside is you cannot run slower than 7Krpm.
From what I remember a line reactor is a good idea if the spindle is more than 12 (cable) feet or thereabouts from the vfd as it helps smooth out the sine wave. The vfd apparently uses the motor to help form the wave, and too much cable reduces this effect. Something like that.
As a reassurance, they (my spindle anyway) have a thermistor build into the body that stops the vfd if they get seriously too hot. Don't really know what the shopbot supplied setup is though.
R.

[paco]

No I haven't. I don't have an amp meter handy... Everything look fine when I enable amp view from the VFD.

From three different sources I got a consistent specifications about the HSD spindle max bearing temperature (not sure if it apply to all model). 120°F would be the normal loaded bearing temperature; that is cutting not too lightly but not too heavily. 135°F (up to 140°F from other source) would be the max rated for spindle equipped with steel bearing like the one I have.

I've ordered a IR thermometer so I'll keep you post on my observations.

[paco]

106°F at the bearing(s) has been the maximum recorded today and 137°F at the motor housing. That is cutting aluminum 4 hours straight at 16000 RPM.

Here's the IR thermometer that I got (http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&rd=1&item=220231955952&ssPa geName=STRK:MEWN:IT&ih=012). I think it's a good deal.

[blackhawk]

Paco - I am a mechanical design engineer for a company that builds electric motors. We build mainly high dollar precision motors for PCB drilling machines and even some CNC metalworking machines. The temperatures that you recorded in your last post should be no problem at all. Any basic bearing setup should be good to 150F. The grease is going to be the limiting factor. I would think that Columbo uses a little better bearing setup than just the "basic", so you should be easily in the clear. Just remember that those IR thermometers are not that accurate. You can probably have +/-10% error on your measurements. The color and shape of your surface can make a big effect on accuracy. A flat black is the best color to detect. Any rounded surface can also throw off your maeasurement. If you always take your measurements at the same point and angle on the motor or spindle, you can probably plot a fair correlation over time to see a problem coming. For all our motor testing, we use thermocouples that we epoxy to the motor housings or endbells. Thermocouples are very precise and actually some of the better Fluke multi-meters have a hookup for thermocouples.

[blackhawk]

I probably exacggerated the +/-10% error on the infrared thermometers. They are probably around +/-5%. The mfr spec may say better, but they are usually assuming ideal conditions.

[paco]

Thanks for your input Brad.

I believe the subject was worth bringing to surface since this piece of equipment (spindle) is quite a bit expensive and we have so much improvement expectations (about cut quality) about it.

I'm glad I have made my homework and acquire the IR thermometer. I now feel more confident about what's going on when the tool work. It feeling very hot, now it feel like about 105°F.

What I'd like to know now is if this 4HP HSD run cooler (motor) on a three phase installation.

[br928]

Paco,

Your spindle can not tell if the input to your VFD is single phase or 3 phase. They usually oversize the drive for single phase applications. In either case the output to the spindle is 3 phase.

The Colombo tech told me the spindle motor would heat up whether it was under a load (cutting) or not. Running my spindle for an hour with no load and the temperatures you recorded are reached.

Apparently these are "normal" operating temperatures. However, others have posted that their spindles never get this warm.

I am pretty sure the old Porter Cable would get this hot if not hotter. But the PC was easily moving 10 times the air flow through it. That’s why I had to use a deflector on the end of it to route the airflow back up and away from the cutting surface. The electric fan on the spindle is blowing straight down and barely moves the sawdust.

I guess this is something I will get used to over time!

[carlcnc]

I discovered something new in researching VFD settings,
Carrier frequency has a lot to do with audible noise AND smootheness of motor,I had to tweak on a new VFD I am using. It is the switching[pulsing?] speed of the IGBTs
just something new to try if your spindle seems to run too warm.
Carl

[paco]

Carl,

where did you find your informations? If I may ask. Thanks.

[carlcnc]

Paco
I got info from manuals from a couple of different brands of vfd, then googled the subject
sorry I didn't bookmark any of the web pages.
Check the manual for yours,they ususally have a few setences about the different parameters.
Carl