On Fri, 27 Jan 2017 09:59:16 -0700, "Bob La Londe"
wrote:

wrote in message
.. .
On Tue, 24 Jan 2017 20:10:36 -0700, "Bob La Londe"
wrote:

wrote in message
...
I made up a little cylindrical reservoir that is pressurrized by a
piston. I tried the injector with some oil that was thicker than the
lube I intend to use. The result was oil that just dripped from the
injector. An online look at DIY injector service made me wonder if the
filter was restricting the flow so I removed the filter. Then, using
oil thinned to the approximate viscosity of the real lube, I tried the
injector again. It squirted pretty good at 30 PSI. The next thing to
address is the reservoir. I'm not sure if a piston sealed with an
O-ring is the best solution for applying pressure. There might be
stiction of the O-ring so that the piston may not move smoothly enough
causing erratic fluid delivery.

If its a lubricating fluid,a nd the o-ring is of a material suitable to
work
with teh fluid it should work fine. Of course you need to size the o-ring
groove properly for "just enough" o-ring engagement. I use o-rings for
low
pressure injection of plastisol (10-30 PSI maybe), and for high pressure
retention of air (4500 PSI). Anyway, if you are worried about stiction
you
can go to a chrome lined hydraulic tube, but I use bare aluminum tube for
a
lot of applications. Low pressure air cylinders, plastisol injector, etc.
Will a piston be controllable and do the job?

An inflatable bladder would probably
work well but I have no idea where to get something like that. I'll
have to see if there is some sort of cup seal that would work better.
In any case I don't think it's a good idea to have the lube exposed to
the shop air, even though it's filtered, because there will always be
a little moisture in the air. When I need pristine air I do have a
nice refrigerated air drying system with particle filters but I don't
generally use it.

I switched my entire shop air distribution over to my refrigeration air
drier and I really like it. I have filter seperators before and after
with
filter seperators on each CNC machine as well, but my main concern is
water,
not the miniscule amount of other stuff that might get in.


The other thing I need to chnage is the spray
pattern. Not sure how that's gonna get done yet. Maybe just a
deflector slipped over the injector will work well enough and that's
my first option. I've got a 555 timer system running and I will be
weighing the oil squirted out once I have the pattern deal figured
out. Once that's done then the timing can be set. I'd like to have
some sort of knob to turn that has a linear relationship to the amount
of fluid delivered. So that a setting of 4 would be twice as much
fluid delivered as a setting of 2.
Eric

Once you get your 555 circuits figured out (two of them probably) you just
need two linear pots to control them.


A piston will do the job, it only needs to move when the pressure is
relieved on one side when the injector is open. The other side of the
piston is pressurized with shop air. I already have the 555 thing
worked out. I have the pause between pulses and pulse length. So when
power is supplied it starts the pulse/pause routine and stops when
power is removed. Most of the time the pulse will be fairly short and
the pause time long because a tap will be getting lubed and this
needs to happen only once per hole. But when milling there will be
short pause times. The timer activation and de-activation will be
programmed with a M code.
Eric

I've been out of the communications contracting business for 27 days now so
forgive me for being a little rusty. I forgot to mention there are modestly
priced timers available already assembled. The Altronixs 6060 board comes
to mind. Yeah they aren't as cheap as the components, but the time to make
it up costs me more than the price of the board.



Or just get a cheap arduino and you can even implement "peak and hold"