No Fog Coolant Mister

John, you could shorten the extension tube to whatever length works best for you, and you could eliminate the nozzle also. Keep in mind that the extension tube is what gives you some "reach" so that the mixing block does not need to be right near the cutter.

The only thing that I need to change is the clamps for my support bars. The original clamps were made of acetal, but it is too slippery to properly hold the 5/16" rod without slipping. I am planning to make some new clamps from aluminum and see if they work any better. Right now it is difficult to get the nozzle to stay where I put it.

Eric, I have not forgotten about you, either. I still plan to make a short video and post it here, I just have not had any shop time lately.
 
Thanks much Terry. this thing looks like what I need. I'll post photo when i get it done - few weeks

best regards,
john
 
Hi Terry,
I found it interesting that the air passage is drilled to .125 and not the .0.90 diameter of the tube. I assumed this was to avoid any venturi effect where the .040 coolant passage lets the coolant into the flow. Pretty subtle.

Cheers.
 
John, sorry I did not reply sooner, I've been out of town since Monday morning, just got home this evening.

I am glad you brought this up about the diameter of the air passage. When the mixing block was first designed, the .125 dimension was somewhat arbitrary, but the block was designed and made before I had any brass tubing on hand. The tubing with it's .090" ID was based entirely on what was available.

This all leads up to a problem that a few users have talked about with the unit 'sputtering' where the coolant seems to come in spurts. I wonder if a smaller diameter for the air passage would help to reduce that problem?? There is no reason that the air passage could not be .090" instead of .125" If you have not yet built yours, John, would you mind trying yours with a .090" air passage and let us know how it works? At some point this summer I plan to make another one and will try the smaller hole, but I have too many irons in the fire to make a new one right now.
 
Hi Terry,
Like yourself I have not had much shop time and had not got the mister working, I was lying in bed recently and a brainwave struck me (very unusual occurrence!), pressure pack spray cans have small pressures and tiny orifices and work well. I thought I would make a nozzle that had an outlet as small as I could drill which was 0.8mm (1/32" or .03"). I tried that which reduced my outlet size by at least 2/3rds and 'bingo' everything is working really well now.
Just thought I would pass my experience on for what it's worth, and thanks again for the project, I will now make a second one to hold WD40 for aluminium.

regards Eric
 
Hah. I made a very nice block out of 6061 - how I love to fly-cut. But guess what? first hole and so far only hole was through at .125. So too late unless I make another one.

Eric are you getting droplets and not mist with your version?

John
 
Definitely fine droplets, no mist that I notice, and the 20psi pressure blows chips away with this smaller opening, however, I still have to properly mount it and use it on a job, just been experimenting so far.
Funny you mentioned fly cutting, that seems to be my latest stumbling block, I cannot seem to get it right, sometimes I do, sometimes not, more practice needed.

Eric
 
Thanks for the input fellas!! I find it surprising that a smaller nozzle did the trick for you, Eric. My nozzle was originally .040" and I increased its size to .090" and it worked better at the larger size. Maybe smaller would have been better?? Guess I will have to make a new nozzle when I have the chance and give it a try.
 
I haven't completed this thing yet. My air-compressor showed up today. It's a one horse California ultraquiet - no snickering. It will only be used for blowing chips and powering the no-fogger. Mine has to be a stealth shop so noise has to be minimal, and besides i'm only making little things. I'm also considering pulsing the liquid flow by solenoid valve and timer. But have to complete no-fogger first, then mess with other modifications.

And thanks Terry for thinking of this thing and Eric for your thoughts.

On flycutting, I'm using Sherline's carbide cutter set to about 2 1/2 inch circle and I don't run it very fast. I take shallow cuts until piece cleans up then feed out slowly and back even more slowly. I get a mirror finish.

I worked in a shop when I was a kid 55 years ago. We built manufacturing machinery. These projects were assembled out of aluminum plate and cold-rolled. All the connections were counter-bored socket-head cap screws. Where alignment was critical joints were keyed or pinned. Every surface including the ones you couldn't see was faced off with a fly-cutter. These things were beautiful.

All we needed to do was get one machine into a customer's plant and after that we got all the custom jobs. They loved the conspicuous precision even where it didn't matter. I loved the work. As Oskar Trumbull Scalbom, the proprietor used to say, "Just like downtown."'

So my designs may not be intelligent, but they tend to look good.


cheers,

John
 
You will love that California Air Tools compressor. I have one of the 3/4 HP units for the basement shop and it certainly is quiet. It is more than adequate for supplying air for the No Fog Mister and for lightly blowing the chips out of an occasional blind hole. Nobody even hears it run, but my 6 HP unit out in the garage makes its presence known to us and the neighbors every time it fires up.
 
Back
Top