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Dribble Cooling on a lathe

The pieces finally came together, and I have the complete Dribble Cooling setup on the Clausing 5914 lathe.

Basically, this is a flood cooling setup with needle valves that allow one to throttle the flow down to a dribble or even a drop now and then.

I gave up on lock-line as it is too large and too hard to adjust, and went to 0.125" diameter soft copper tubing. Actually, the tubing is cheaper than lock line: 50' for $25 at the local plumbing supply house.

The setup consists of a cheap 3-gallon coolant pump, some 3/8" vinyl tubing going to a manifold bolted to a magnetic base stuck to the lathe carriage. The manifold has a small ball valve that turns flow on and off, and two needle valves with 1/8" copper tubing applicator tubes about 15" long. Only one needle valve and tube is in current use.

One bends the tube so it ends just above the workpiece and is aligned with the cutting bit, and adjusts the needle valve to drip coolant onto the spinning workpiece.

I tested this by doing some cutoffs of 14L12 steel 1.5" diameter rod, using a BXA-7 cutoff tool (0.125" wide HSS blade, normal rotation) and a reversed Dorian 7-71 holder with 2mm wide inserts in a SGIH 26-2 blade (reverse rotation), both manually fed. Both worked smoothly, and in silence, at about 500 rpm. No drama at all.

The coolant is Rustlick WS-5050 soluble oil in water, 15:1 dilution.

I think that the cutoff process was helped by the extra coolant on target. While total coolant usage was a bit higher than with the mister, far more of the coolant ended up on target. Said another way, with the mister the cutting point may have been starved of coolant.

And I didn't need to wear the respirator. No mist. No wifely complaints about the drifting fog or smell either.

This may be a keeper, and it cost far less than the fancy mist coolant systems. I will probably have to make and install a chip tray drain, as I creep towards full flood coolant.

Joe Gwinn

Reply to
Joseph Gwinn
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For small-tipped tools, I wonder if reducing the 1/8 copper to a needle-type nozzle (which I think I've seen with 1/8 npt ends) for a very fine stream so that the coolant can be delivered at nearly the exact rate that it is "consumed" would be feasible -- depending on the tool/cutting area.

Drops are OK, but a continuous true micro-stream would probably serve the cause optimally.

Reply to
Proctologically Violated©®

Did you try comparing your cutting performance (such as resulting finish, tool wear etc) with and without coolant?

Try comparing the finish, you may learn something interesting.

i
Reply to
Ignoramus21117

For parting I apply the cutting oil at the bottom of the groove with a needle oiler bottle. It's inconvenient to do but gives good results with a minimum of oil and no extra plumbing or air pollution. The rate is perhaps a drop every 5 - 10 seconds and the chip carries almost all of it away. I'm ambidextrous enough to hold the bottle in place with one hand and feed evenly with the other, otherwise a grease gun needle point on a hose might work.

jsw

Reply to
Jim Wilkins

You can do this without the pump if you hang the coolant tank (coffee can, maybe) from the ceiling and let it gravity feed.

Reply to
rangerssuck

Yep. The coolant pump zero-flow pressure is a few psi, maybe 5 psi, so a tank hanging from the ceiling will generate adequate pressure. But a coffee can may not be big enough.

For the record, the 1 gallon Little Giant VMC-1 coolant pump has a 11.5 foot head at zero flow.

Joe Gwinn

Reply to
Joseph Gwinn

I never ran dry, except as a test. Wet is much better, in every respect, except for a few materials, such as brass and cast iron.

What I'm seeing with the dribble coolant is that with the mister it appears that I was not getting quite enough coolant on target.

Joe Gwinn

Reply to
Joseph Gwinn

I have been thinking about this, and DoN also suggested using a needle.

What I will probably do is to make a little brass adapter and solder a grease needle into the end of a 0.125" copper tube, to test the issue.

Joe Gwinn

Reply to
Joseph Gwinn

I don't know that I'm that coordinated.

The dribbler does a drop every 5-10 seconds as well, but I don't know if that's enough. This is the point of the thread about using a needle tip. so a smaller volume can be delivered continuously.

Joe Gwinn

Reply to
Joseph Gwinn

As always, the interesting part is to do some hands on comparisons. Whatever I tried, convinced me that flood coolant is superior in every respect. I did have to add various shields to my lathe to avoid making a big mess, though.

i
Reply to
Ignoramus10071

Yes. I will be adding shields and a drain, it seems.

Joe Gwinn

Reply to
Joseph Gwinn

What's that Lassie? You say that Joseph Gwinn fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Thu, 25 Jun 2009 23:36:42 -0400:

At many hardware stores you can buy brass tubing in sizes that will fit into one another nicely. You can solder up a nice "needle" that you can set onto the workpiece right where the cut is to be made. If you make it long enough, it will have a little spring to it so that it will follow the cut dia. as you go.

Reply to
dan

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