On Mon, 09 Jan 2017 18:00:18 -0800, mike wrote:

On 1/9/2017 5:42 PM, Jim Wilkins wrote:
wrote in message
...
On Mon, 09 Jan 2017 16:51:17 -0600, Tim Wescott
wrote:

On Mon, 09 Jan 2017 12:27:25 -0800, etpm wrote:

Greetings Clare,
I just thought a few minutes ago how a fuel injector might be a
good way
to apply Minimum Quantity Lubrication to cutting tools. I figure
you or
someone else here must know what the minimum amount of fuel is
that can
be delivered from a typical gasoline engine fuel injector.
Gasoline is
thinner than the MQL fluids but maybe the injector would work
anyway.
The thinnest MQL fluids I use are water thin or pretty close to
water
thin. The thickest has a viscosity camparable to or slightly less
than 5
weight motor oil. Actually less than 5 weight. Maybe 5 weight and
kerosene mixed 1/2 and 1/2. I can certainly pressurize a liquid
reservoir to the required pressure. Maybe a trip to the wrecking
yard
for a ruel pump and some injectors is in my future.
Thanks,
Eric

I'm not Claire, or necessarily even competent. But I can pull
numbers
out of my ass and do math on them:

60MPH / 30MPG = 2 gallons/hour

3000 RPM = 50 rev/sec. Assume a 4-cylinder, so 100 squirts/second

(2 gal/hr) * (1hr / (3600sec)) / (100 squirt/second) = 5.6 x 10^-6
gallons/squirt.

(5.6 x 10^-6 gal/squirt) * (128 ounce/gal) = 700 x 10^-6
ounce/squirt.

(700 x 10^-6 oz/squirt) * (30 cc/oz) = 0.02 cc/squirt.

This help? Higher viscosity means that the fluid delivery will
be -- uh
-- less. Worse, higher viscosity may mean that you're screwed if
you're
looking for a particular spray pattern. If electronic fuel
injection is
a thing in diesels, maybe use an injector from one of them?
Greetings Tim,
I wish you would pull those numbers from somewhere else. Even your
nose would be better. Nevertheless I held my nose and used some of
the
first numbers you pulled out of your ass: gallons per hour. I then
converted those numbers to cubic centimeters. Then did similar
calculations to yours and arrived at the same number you did. Thanks
for making me look too lazy to figure out how much fuel is
squirted.
.02 cc might be just about what I need. If too much I could lower
the
delivery pressure. The spray pattern may not be perfect but I can
modify that if need be with a nozzle downstream from the injector.
Or
I can just use the injector as a timed metering valve upstream from
whatever nozzle. Cool.
Cheers,
Eric

With water solutions a chemists' rule of thumb is 20 drops per cc.
-jsw


Isn't this kind of injector a valve that requires high pressure feed?
What about using the guts of an airless paint sprayer?
You can adjust pulse rate and the throw/volume per pulse.
An airless paint sprayer would deliver way too much but thanks anyway
for the suggestion. Gasoline fuel injectors are often supplied with
fuel pressures less than the typical 90 PSI air that I use in my shop.
A reservoir with the MQL could be easily pressurized by shop air. The
air and lube can be kept apart by using a piston to apply pressure to
the lube. Tim's example of .02 cc might even be at the high end of the
quantity of MQL needed. My son told me he has some injectors that I
can use to experiment with. Having a constant pressure head means that
lube dispensing will be instant once the injector is triggered.
Eric