Mini Mill Coolant Return Problems

[knkprecision]

Hello All,

New to this forum and need some help / advise.
I have a 2005 mini mill I bought used with very low hrs 9 months ago. Overall I am pretty impressed with this little machine. Havnt had any problems whatsoever with it since the day it was installed, except for coolant return.

It is equiped with the standard pump which works perfectly. Problem Im having is coolant builds up inside machine and doesnt drain back into reservoir fast enough. Between the inside of the machine and the reservoir there appears to be another reservoir that works in conjunction with the built in oil skimmer(which doesnt work very well either). Inside the machine I cant even see any drain holes. Where are these little guys hiding ? Obviously drain holes / slots are getting plugged by chips. From inside the main reservoir I can see slots that go thru to the skimmer reservoir. I hav blown thru these with air gun and it helps a little but not much. Coolant is basically just dripping from these slots.

Any suggestions / advise ??? Im sure someone out there has encountered the same problem.

Thanks.....knkprecision

[dougtyler]

While doing a complete cleaning on mine, I notice that a couple of the drain holes had been covered over with paint. The little slits that are along the bottom of the pan seem to get plugged pretty easily.

[knkprecision]

While doing a complete cleaning on mine, I notice that a couple of the drain holes had been covered over with paint. The little slits that are along the bottom of the pan seem to get plugged pretty easily.

My machine has a chip auger. Where are these drain holes on your machine. I cant see any drain holes on mine at all. Are they at the bottom of the chip auger trough ?

[Geof]

Clean out all the chips and you will see the drain holes, slots actually; they do clog very readily.

My solution is to have a blow gun with a long nozzle to blow backwards from inside the coolant tank. If you drag the nozzle against the sloping underside of the metal between the chip space and the tank you can feel the end bump the slots. I just try and run it up and down the slot while blowing air.

[knkprecision]

Thanks for your input Geof.

Are the slots in the bottom of the auger trough ? I havnt totally cleaned out the bottom of the auger yet. I cant see any holes or slots anywhere else inside the machine. And I hav blown air up thru those slots from inside the bottom of the tank. Helps a little.

Im pretty positive there is a second reservoir between the inside of the machine and the main tank. This is where the machine skims the oil off the coolant.

So blowing air up thru the slots from inside the main tank is just actually blowing into the oil skimmer reservoir.

The coolant isnt draining out of the inside of the machine and into oil skimmer tank fast enough.

I was thinking about drilling some other holes thru the inside of the machine. But then im faced with chips clogging those holes or worse passing thru.

Has anyone else encountered this problem. And what nifty idea did you come up with to fix it ?

Thanks in advance