New PM-727V arrived today, Happy ??

[mikey]

Just thought I'd check temps, after running in H-3 (gear selection) for 15-20 minutes side of motor was 142, top of head near motor 116, all other parts of head 102-109, spindle bearings 113. Temp taken with digital laser thermometer, motor speed kept high but not max to provide best fan efficiency. I think it will only get better with more run time.
Anthony

Are you able to directly measure temps at the spindle bearings? I mean shoot the laser directly at the upper and lower spindle bearings. If so, most quality bearings should not get above ~100 degree C. You cannot determine if the bearing is running hot by measuring the temp of the housing - too many variables.

For those of you who are thinking about re-packing your spindle bearings (tapered roller bearings), remember that you should clean the bearing thoroughly, then pack only 1/4 to 1/3 of the bearing with a high quality bearing grease. Overpacking the bearing like you do with wheel bearings will result in overheating and may destroy the bearing. You should also slowly run in the bearing after repacking it to allow the grease to warm up and re-distribute.

 

[GunsOfNavarone]

I think when I read PM's suggestion, it was really low, like 20-30% coverage...definitely not a "packing" style like wheel bearing. There really isn't much grease needed at all so get that Keblex (sp?) one small tube is plenty and it's pretty light stuff. You don't want wheel bearing grease. My bearings stay right at 70-90* (depending the ambient room temp.) I'm pretty confident you'll be fine...don't sweat it and just plan on changing out to better bearing when the time comes. Hopefully you're up and running after all this time!

 

[GTPI]

Are you able to directly measure temps at the spindle bearings? I mean shoot the laser directly at the upper and lower spindle bearings. If so, most quality bearings should not get above ~100 degree C. You cannot determine if the bearing is running hot by measuring the temp of the housing - too many variables.

Yes I agree, in my post I detailed temperatures, where they were taken and method used. I believe I covered it exactly as you mentioned, see the full results, the spindle bearings ran at 113
The machine is new so as far as the quality of the bearings goes they are what PM installed, the amount of grease used is unknown .
If possible I'd appreciate more info on replacing the spindle bearings and where to source high quality replacements.
Thanks
Anthony

 

[GunsOfNavarone]

I can pull the info from Amazon where I got mine, bearing replacement is very easy, though I never replaced the bearings at the top as I was unsure on those even though I have them. (not the top spindle, the ones you see around draw bar) They aren't part of the issue anyway.
30207 Nachi
30205 Nachi

 

[GTPI]

I can pull the info from Amazon where I got mine, bearing replacement is very easy, though I never replaced the bearings at the top as I was unsure on those even though I have them. (not the top spindle, the ones you see around draw bar) They aren't part of the issue anyway.
30207 Nachi
30205 Nachi

So the bearings that you pointed out are housed in the quill or on the spindle? Will I need to press them off & on. Any details on removal would be helpful, I want to get familiar with servicing them before I have a problem .
Thanks much

 

[mikey]

Yes I agree, in my post I detailed temperatures, where they were taken and method used. I believe I covered it exactly as you mentioned, see the full results, the spindle bearings ran at 113
The machine is new so as far as the quality of the bearings goes they are what PM installed, the amount of grease used is unknown .
If possible I'd appreciate more info on replacing the spindle bearings and where to source high quality replacements.
Thanks
Anthony

Okay, that's about 45 deg. C, which is normal operating temp for a spindle bearing.

 

[GunsOfNavarone]

I think you'll be fine for a while, this, like all things will pass....
I'll see if I can put some pictures together, it's probably 8 steps, 2 hidden grub screws, one semi-tricky tension spring. Bearings are a snug fit, never had to pull out a bearing puller/race puller/shop press. I literally could do it in 30 minutes now (had to play with bearing pre-load so I had to do it 3 times in a row.
You might as well get your money's worth out of those bearings, surprisingly, life didn't really improve with bearing replacement.
Did you get that surging rpm thing figured out?

 

[GTPI]

I think you'll be fine for a while, this, like all things will pass....
I'll see if I can put some pictures together, it's probably 8 steps, 2 hidden grub screws, one semi-tricky tension spring. Bearings are a snug fit, never had to pull out a bearing puller/race puller/shop press. I literally could do it in 30 minutes now (had to play with bearing pre-load so I had to do it 3 times in a row.
You might as well get your money's worth out of those bearings, surprisingly, life didn't really improve with bearing replacement.
Did you get that surging rpm thing figured out?

Thanks for the info. I never found the cause of the surging , I went over all connection, it only did it the first time it ran and never again. Maybe it was a bat in the bearings, I'll check the oil.
I did notice that the advertised max rpm is 3000, this machine will run smooth at 3500 rpm. Maybe the motor swap? sure it's OK.
What I noticed is that it will operate from 0 to the max rpm stated for each gear, the low speed in each range is just recommend startling point correct ? Hope that made sense. (new guy stuff)
Thanks
Anthony

 

[macardoso]

I have a G0704 - Different machine but hopefully applicable. I've run the factory original spindle bearings as well as 2 replacement sets of angular contact bearings (first set I installed poorly and destroyed). The most recent set was packed with Kluber IsoFlex NBU 35 for a 30% fill.

My spindle will get up to 140*F @ 5000 rpm. I can run it all day long at this temp and I have zero problems. It has been running for years this way. Personally I'd be thrilled with 115*F.

Sounds like you are up and running, time to start making chips. You can always revisit issues down the road.

 

[GunsOfNavarone]

@macardoso holy moly! 5K rpm's? Is this the stock setup? Yes Kluber is the grease I used but couldn't remember the name...it's crazy expensive but for a spindle bearing replacement, you don't need much. I really don't think GTPI needs new bearings at this point, but if he's just gathering info for someday, I get that, this place is invaluable for that.
Your 5k versus (well my PM only gets up to 1750 prm, OP's goes to 3 k?) I'd expect much higher temps. But again, I don't believe he has any issues to worry about. His purchase has had plenty already, I think he's a bit shell shocked, don't blame him.