On Mon, 09 Jan 2017 16:48:22 -0800, etpm wrote:

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

If you need less than that you can probably go down from there -- these
motors do have to idle, after all.

Actually driving the injector electronically may be a challenge. I don't
know what they use in practice, but a TIP-32 from Radio Shack probably
won't be sufficient, although a 555 circuit to time it might be.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!