No Fog Coolant Mister

Hopefully the rest of the ingredients will show up today. Following Eric's lead, I'm going to make a nozzle. 'Ought to be a bit of a challenge without a lathe, but I'll forgo the tapered nose. Terry, you were right about drilling the .040 hole. It took two tries, fortunately, the bit that broke hadn't penetrated into the .125 passage. I had planned to use two regulators, one for the air and one for the fluid, but decided that with the needle valves on each line there were too many variables and the thing would be hard to control.

Having a single regulator does provoke a question, though. The height of the fluid container relative to the mixing block will affect flow if the air pressure to the fluid container and the block is the same. Has either of you messed with this?
 
I have not experimented with it, but have always kept my reservoir below the height of the nozzle. When I shut off the air, the flow of fluid ceases as well and it does not continue to siphon out through the nozzle as it would if the reservoir were higher.
 
Thanks for the note, Terry. My mixer is finished, photo to follow. Being latheless, threading the brass tube was a bit of a challenge, but I finally hit on chucking it in the drill press and putting a die in holder on the table. I was able to turn the chuck by hand to get about 3/8 inch of thread which seemed enough. Filter holder was ordered from filtersfast which despite their name is none too swift, I'm still waiting.
 
Hmmm. When I ordered from them I got everything rather quickly. Sorry to hear you are experiencing a delay.

Keep in mind that when I listed Filtersfast.com on the bill of materials I chose them only because they had everything I needed and the prices were reasonable. Other builders can choose another supplier if they wish, but I had good luck with the vendors listed on the BOM.
 
Hi Guys,
This is what my effort produced:

fogless1.jpg

The filter holder showed up on Saturday. Terry you chose well, the thing is really substantial. I'm going to try it with the.090 throat first and then if that doesn't work, I bought the 1/4 inch hex brass to make a nozzle with.

And again, thanks to you all for a useful design.

john
 
When I get my mill mounted to its new table ,I'll have to make this mister too. Love the fact it dosent use gallons of fluid to work. Thanks for the plans .
 
At long last, I cleared my backlog of the less fun things, and got started on my SlimVise project. First act was to make two smaller pieces out of a big one. This was more of an experiment to see how the no-fogger worked than the best way to do this.

fogless2.jpg

It worked just fine, and without a nozzle. i ran 20 psi on the system. The adjustment of the coolant valve is really twitchy though, possibly because this HomeDepot valve is not intended to meter. So next "improvement" is to find a real metering valve. The thing that's nice about this is that you can feel the air stream cool when the coolant starts to feed and also you can see very small droplets accumulate if you aim it at a piece of paper.

I'm glad i made this thing.
 
Mine is touchy about its adjustment also, so it might not be your valve. I am considering making my own needle valve so that I can better regulate the coolant flow, but there are too many other projects going right now. Another method that I have considered is to use two regulators. One set at about 20 PSI for the air flow through the mixer, and the other set at 30 or 40 PSI to provide pressure for the fluid. I believe that the surface tension of the fluid is high enough that at 20 PSI there is not enough pressure to keep the fluid moving past the needle valve when it is barely even open. More pressure behind the fluid might help, but I don't know for sure.
 
Hi Terry,
I bought two regulators with the thought that the fluid and air feeds might work better with different pressures although I was thinking of less pressure on the fluid, maybe depending more on venturi effect to pick it up. The valves I have are not really needle valves like you used to use for air-correction in carburetors so it's more of an off-and-more-or-less-on choice, not a a gently ramping increase in flow. You may be right that the stickiness of the coolant could clog a real metering valve. I guess I'll have to see if i can find one, and then maybe also mess with the air-pressure too.

I have some old propane valves around which have long needles, maybe one of them can be modified to do this job better.
 
terrywerm said:
Mine is touchy about its adjustment also, so it might not be your valve. I am considering making my own needle valve so that I can better regulate the coolant flow, but there are too many other projects going right now. Another method that I have considered is to use two regulators. One set at about 20 PSI for the air flow through the mixer, and the other set at 30 or 40 PSI to provide pressure for the fluid. I believe that the surface tension of the fluid is high enough that at 20 PSI there is not enough pressure to keep the fluid moving past the needle valve when it is barely even open. More pressure behind the fluid might help, but I don't know for sure.
Click to expand...

j ferguson said:
Hi Terry,
I bought two regulators with the thought that the fluid and air feeds might work better with different pressures although I was thinking of less pressure on the fluid, maybe depending more on venturi effect to pick it up. The valves I have are not really needle valves like you used to use for air-correction in carburetors so it's more of an off-and-more-or-less-on choice, not a a gently ramping increase in flow. You may be right that the stickiness of the coolant could clog a real metering valve. I guess I'll have to see if i can find one, and then maybe also mess with the air-pressure too.

I have some old propane valves around which have long needles, maybe one of them can be modified to do this job better.
Click to expand...

I run mine at a 15 PSI differential, 45 on the air and 60 on the fluid. That way I'm assured of having fluid flow at all delivery rates. I'm using pneumatic flow controls for the fine adjustment, about 16 inches back from the outlet for both fluid and air at the mixing tee.
 
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