Running tm1 spindle at 25rpm for hours on end... Bad?

S

sirAIG

Aluminum

Joined

Jan 10, 2019

Location

State College

• Jun 21, 2020

• #1

As title suggests.

I have to lap a bunch (200) of thin 3/4" dia disks to mirror polish. It will either be done by hand, or on my tm1. I have everything done and made and it works, but best results are had at 25rpm (perhaps even slower, but that's the slowest I can program without an alarm)

It will take at least 6 hours to polish all of these. Is this at all in any way damaging to the spindle motor? There is ZERO load being applied as the lapping tool I made for the spindle is spring loaded.

Thoughts?

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kustomizer

Diamond

Joined

Aug 17, 2007

Location

North Fork Idaho

• Jun 21, 2020

• #2

I would think it would throw an overheat alarm long before anything was damaged, Haas is good about that. You might feel the spindle nose now and again to make sure it doesn't get hot though I can't see how it could.

 

Phil in Montana

Stainless

Joined

Jul 31, 2007

Location

Missoula Mt

• Jun 21, 2020

• #3

What about at the end of each disc you raise off the part and run the spindle at 1200 rpm for 30 secs to cool it down?...Phil

 

S

sirAIG

Aluminum

Joined

Jan 10, 2019

Location

State College

• Jun 21, 2020

• #4

Pardon my noobiness... Why would the spindle be getting (potentially) extra warm running this slow? and how does running it faster cool it down? I can hear the cooling fan atop the motor kicking on as it should.

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Phil in Montana

Stainless

Joined

Jul 31, 2007

Location

Missoula Mt

• Jun 21, 2020

• #5

Spindle Motor will not cool at the low speed...Phil

 

S

sirAIG

Aluminum

Joined

Jan 10, 2019

Location

State College

• Jun 21, 2020

• #6

How is that possible. The fan kicks in all the same.

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ChipSplitter

Titanium

Joined

May 23, 2019

Location

Maybe

• Jun 22, 2020

• #7

Theory goes that you need RPM to work the spindle oil up into the bearings.
Gravity causes it to settle and running it without enough speed could cause them to run dry.
That's what Haas told me.........

Lubrication would be the problem, not heat.
And you're right, the fan runs almost constantly when the spindle is on.

I like Phil's idea about doing a dry cycle every few minutes. That should do the trick, IMO.

 

C

coyoinu

Aluminum

Joined

Oct 6, 2012

Location

Orange county, CA

• Jun 22, 2020

• #8

If this is an older machine, you're probably okay. If it's NGC, you might want to consult your HFO first. I've seen new lathe vector drives burn up doing something like that, but I think that kink has been worked out of the software.

As far as lubrication goes, your spindle is likely sealed and permanently greased.

 

D

D.D.Machine

Stainless

Joined

Dec 10, 2003

Location

poulsbo, wa, usa

• Jun 22, 2020

• #9

I would do it ,, just every hour or so give it like 5 min at like 750 RPM to move the grease around ,,

 

S

sirAIG

Aluminum

Joined

Jan 10, 2019

Location

State College

• Jun 22, 2020

• #10

Thanks for the enlightenment. I hadn't considered the spindle lubrication since it's grease packed, but that makes sense either way. Thanks for the feedback.

Machine is pre ngc. 2004

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S

Stirling

Hot Rolled

Joined

Dec 11, 2013

Location

Alberta canada

• Jul 4, 2020

• #11

Id just keep an eye on the drives and motor as they are running outside if the typical working conditions/electrical frequencies. I doubt there is concern

i cannot see the spindle having any issues, do your warm up cycle in the morning. if you walk away for a break bump it to 1000 rpm. to redistribute lubrication.
but 25 rpm with no load, I would not hesitate on mine.

if its something that comes up often I would consider a different process thought, or a drill press. keeps the spindle ready to cut (or cutting another job