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Coolant leaks

rimcanyon

Diamond
Joined
Sep 28, 2002
Location
Salinas, CA USA
I have a lot of coolant leaking on the floor, so trying to figure out where it is coming from. The projects I have been working on lately direct a lot of coolant towards the FP2NC column, and the oil seems to be seeping from under the machine. I pulled out the coolant tank and checked the hose from the machine base, but did not see any obvious leaks. The level of coolant in the tank is about the same as the top of the column drain hose top. The hose from the table enclosure to the tank is not leaking. The coolant pump output tubing is not leaking. The oil catch basin at the rear of the machine was pretty full, so I emptied it (the level was about ½" above the drain hole from the interior of the column). I am assuming that the catch basin is designed to overflow into the coolant drain on the right side of the base, is that correct?
 
Dave:
First to establish is the liquid coolant or way oil?

Several sources for way oil....First off oil from lubing the vertical screw eventually finds its way into the base of the machine below the screw.
Eventually enough will collect to leak out of the access window in the side of the base (non operators side, just below the "Z" servo, covered by a sheet metal plate that just snaps in)

You need to remove that cover from time to time and muck out the collected way oil...This is a dirty job as the oil gets mixed with rubber dust from the drive belt that drives the "Z" ball screw.

Additional notes, there are catch basins below the vertical box ways that duct the wast way oil into channels that run under the main vertical casting. That oil eventually ends in draining into the catch
basin at the right rear of the machine.

Not sure about the idea that the basin is designed to drain into the coolant on the left side....Do not thing you ever want to mix the way oil with the coolant.
The drain at the left is there to drain any coolant that happens to fall on to the base ...be sure that the drain fitting is not leaking between the fitting and the casting that it passes through.

Think its good practice to level your machine with the front slightly high as this aids coolant in draining and the waste way oil better flow to the catch basin.

There are also potential leaks from the hydraulic system that can occur. Have a look behind the side panel where the way pump / tank are (non operators side)

Cheers Ross
 
Ross, thanks for the suggestions. The leak is definitely coolant, and the floor gets flooded, lots of it, enough to spread out 3-4 feet and it keeps coming after the machine is shut off. I will re-level the machine high in the front and see if that helps. Right now the table is level within .001" side to side and front to back. I set it up that way because I am truing up rough castings using a 4" diameter face mill, and it helps to be able to use a level when shimming up the castings on the table for the first (reference surface) cut. The previous job was machining some discs (farming implement) which had a domed surface. So for both jobs the coolant was flowing towards the column a lot. However, I did not see much coolant in the trough around the base and I did not see a lot of drips onto the floor.

Thanks for the education on the drainage around the screw. I have never had that cover off, did not know it existed. Inside it was clean, but maybe that just means it has been seeing a lot of flow. It looks like the compartment drains to the rear catch basin, but it also has two overflow drains that appear to go out the bottom of the machine. It also looks like the high water mark is about the same height as the overflows. Here is a picture:

IMG_0545.jpg

I suspect that coolant flows out through the gaps around the column, and from there it finds its way into the front compartment:

IMG_0546.jpg

And I am also thinking that the rear catch basin would not overflow into the drain on the left before the fluid level in the front compartment overflows:

IMG_0547.jpg

You can also see the high water line in the rear catch basin.

So what else should I look at, is there more to it, i.e. additional paths where coolant might flow?

I'm a bit suprised that this problem does not appear to be more common, judging by the lack of replies to the thread, which makes me think it is probably not as simple as re-leveling the machine and draining the rear catch basin more frequently.
 
Dave:
Not sure. seems you have looked at the possible sources.
Rear coolant catch tray (operators side) looks pretty dry, seems if the coolant was escaping the enclosure i would think some if not all would be getting to the
base and then to the catch tray .....

Are you using soluble oil as coolant a synthetic or cutting oil?
Cheers Ross
 
Hi Dave,

I suspect that coolant flows out through the gaps around the column, and from there it finds its way into the front compartment.

Just to ask the obvious, have you pulled off the metal cover plate on the top of the vertical table, that covers the seals around the column, and checked those seals? If you are correct, that might also show the path that the coolant is taking.

Cheers,
Bruce
 
My deckel drains coolant to the floor if the enclosure is not sealed with sealant to the bottom of "knee" where the table is fixed. My enclosure might be different, but thats what i have noticed.
 
Hi Dave,



Just to ask the obvious, have you pulled off the metal cover plate on the top of the vertical table, that covers the seals around the column, and checked those seals? If you are correct, that might also show the path that the coolant is taking.

Cheers,
Bruce

I haven't recently, but the seals are relatively new, maybe a year old, and the problem has occurred off and on since I bought the machine. The knee surface between the table and the column has almost zero pitch, so coolant that flows there does not drain rapidly, and coolant that gets slung by a cutter against the column also does not drain rapidly, so the gaps on each side, between the column and the enclosure are probably the drainage path. I'm considering making a coolant shield out of some sheetmetal to better drain coolant from that area.
 








 
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