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.
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
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.
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.
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.
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.
Jim Wilk> > > "Joseph Gwinn" wrote in message
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.
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.
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.