TSC rusting in spindles

[So not a Guru]

We have a problem I've never come across before. In the last year and a half we've had 2 spindles get a ton of rust, in the thru spindle coolant column, of the spindle. One of them we had completely rebuilt last October & we just had to send it out again!

We have used the same coolant for years, although we are going to have a rep from Quaker-Houghton come out next week to evaluate our operation. I don't think that the coolant is the issue though, as we have virtually no rust in the machines anywhere else.

We have a robust water separation setup at our compressors & both machines have mist & water separators.

Anyone have any ideas as to what could be causing this?

[JParis]

Just now, So not a Guru said:

Anyone have any ideas as to what could be causing this?

Coolant concentration not likely high enough

[BILL HUNTER]

Are you running cast iron? Cast iron is brutal on rusting in draw tubes.

[gcode]

are you filtering the coolant

[JoshC]

25 minutes ago, JParis said:

Coolant concentration not likely high enough

^+1 to that, did you check the coolant concentration and are you using an oil based lubricant or water based? if its water based i would suggest reaching out to your coolant vendor to see what oil based coolants

[So not a Guru]

50 minutes ago, JParis said:

Coolant concentration not likely high enough

We run it at the recommended refractometer reading of 5 - 7, usually on the high side, and we check & adjust every morning. I would expect rust on the tables & covers, if it was thecoolant.

49 minutes ago, BILL HUNTER said:

Are you running cast iron? Cast iron is brutal on rusting in draw tubes.

No, we've never ran cast iron in this shop.

47 minutes ago, gcode said:

are you filtering the coolant

Yes, the TSC runs thru a 25 micron filter.

29 minutes ago, JoshC said:

if its water based i would suggest reaching out to your coolant vendor to see what oil based coolants

It's a full synthetic water diluted.

We are having a rep come in next week.

Once again though, wouldn't we have rust in other areas of the machines, if the issue was coolant based?

[JoshC]

40 minutes ago, So not a Guru said:

Once again though, wouldn't we have rust in other areas of the machines, if the issue was coolant based?

yea that is a good point, probably would have it other places as well so i am not sure

[Machineguy]

Check your water hardness and what else is in it. This effects coolant big time.

The water hardness wont let the coolant mix correctly.

We run cast iron on one job. We have to change the filters more often.

[Rstewart]

I personally have never had good luck or trusted Full Syn coolant.  I had rust issues in the past 

[Matthew Hajicek - Singularity]

+++ to Machineguy.  I had rusting issues here until I had a water deionizing system put in.

[So not a Guru]

41 minutes ago, Machineguy said:

Check your water hardness and what else is in it. This effects coolant big time.

The water hardness wont let the coolant mix correctly.

We run cast iron on one job. We have to change the filters more often.

This is one of the things the rep is supposed to investigate for us.

[BSmith23]

I think the other thing you need to consider is whether or not you are getting the coolant out from the spindle after you are done running your TSC.  If you have air blast thru your spindle as well, make sure you run that to purge the excess coolant out so that it's not "standing" above the tool.  I know that most of it drains out, esp after tool change.  But if you run an extra 5-10 seconds of air blast after running TSC, that might cure your problem.  We always run that purge here, except on our DMG, which doesn't have the thru air option.

 

Brent

[So not a Guru]

18 minutes ago, BSmith23 said:

I think the other thing you need to consider is whether or not you are getting the coolant out from the spindle after you are done running your TSC.  If you have air blast thru your spindle as well, make sure you run that to purge the excess coolant out so that it's not "standing" above the tool.  I know that most of it drains out, esp after tool change.  But if you run an extra 5-10 seconds of air blast after running TSC, that might cure your problem.  We always run that purge here, except on our DMG, which doesn't have the thru air option.

 

Brent

 

Thanks!

I was just discussing this with the Mazak tech, who is installing the spindle. Most of our TSC use is with thru-coolant carbide drills, a lot of them have very small coolant holes. The machines use an air blast to clear the coolant from the column, at the end of each operation, but you can often see coolant still draining from the drills after the air blast has ceased. We are considering increasing the air blast duration.

[Sumac Andy]

Hi.

A problem we had here along time ago..... high magnesium content aluminiums made our coolant split, sometimes the only way we knew was through oversized tapped or reamed holes.  The strength of the coolant was often shown as 'normal' or high also, we had a new (same) coolant with additives to cover this machine).  Our aluminium was a tooling plate issue (5000 series, I think?), worth investigating? I wonder if the pressure of the water/oil 'mix' is blasting through the tubes as normal, removing oil as it jets through, leaving a very week mixture inside?  Interested to see the outcome of this.  Andy.

Edited September 2, 2020 by Sumac Andy
spelling! My OCD!

[Leon82]

Sometimes the o-rings need to be changed. Our makino says to change every 2000 hours.

At the end of the program you can also switch to an empty tool and blow the spindle out for a longer time so it doesn't increase your chip to chip time.