Which filter for air assist?

[Bob Savage]

I've got belt driven compressor I plan on using for air assist, and am looking for input on what to use for conditioning the air to eliminate oil and water. Any input?

http://www.grainger.com/Grainger/categories/pneumatics-and-hydraulics/air-treatment/filter-regulator

[Scott Shepherd]

Depends on the laser you get. The Epilog and others use a air sweep, so water isn't as critical. The ULS has air-curtains on all the mirrors and the lens box is pressurized to some degree as the air shoot down a cone, with the beam, so the air is directed directly down into the cut.

If one drop of water gets into that system, it can hit a mirror, the beam hits it, heats it all up and cracks the lens.

So it really depends on what you get.

[Bob Savage]

Well, why didn't I know there would some dynamics to this? :)

Thanks Scott. I'll be back when I finally find a laser to buy and reintroduce the question.

[Bob Savage]

Actually, perhaps I should rephrase the question.

Does anybody have input on a filter/regulator that will clean both oil and water from the lines, based on that list at Granger? Let's just assume I want dry air, regardless of the minimum system requirements.

[Scott Shepherd]

Bob, I tried a lot of things and finally ended up with a SpeedAire refridgerated dryer. It was expensive, but I now have dry air all the time. I tried all the cheapy ways out and couldn't seem to get them to work for any length of time prior to needing to be changed. So I was spending money changing things out to keep the air dry. Now, I just turn the air on and go.

[Bob Savage]

Bob, I tried a lot of things and finally ended up with a SpeedAire refridgerated dryer. It was expensive, but I now have dry air all the time. I tried all the cheapy ways out and couldn't seem to get them to work for any length of time prior to needing to be changed. So I was spending money changing things out to keep the air dry. Now, I just turn the air on and go.

Just did a search... my heart stopped momentarilly, but it's started again. Those are pricey!

[Bob Savage]

So, the Epilog is looking pretty good. :)

[Scott Shepherd]

:) Not so pricey when running a job at 7:00 on Sunday night that's due Monday morning and the stuff is saturated and all the stores are closed to buy the replacement :)

Honestly, I just got sick of trying to figure out the cheap work around. It was $20 here, $20 there. Buy once, cry once, it's done, now I can use it to run my paint gun as well, so it serves more than one use.

[Bob Savage]

:) Not so pricey when running a job at 7:00 on Sunday night that's due Monday morning and the stuff is saturated and all the stores are closed to buy the replacement :)

Honestly, I just got sick of trying to figure out the cheap work around. It was $20 here, $20 there. Buy once, cry once, it's done, now I can use it to run my paint gun as well, so it serves more than one use.

I hear you. I'm going to have a small "hobby" shop in my garage, so my concern is on a smaller scale, albeit still important that I don't whack anything with water or oil. I'd be O.K. spending $80-$120 on a "decent" filter, but based upon your feedback, I'm not sure that's reasonable.

[Paul Brinkmeyer]

I use a small airbrush compressor and run about 7 psi over the optics. It is plenty of air even when I use the nozzel. If I want to cut wood and use the air nozzel I run two samll airbrush compressors and that bumps the air pressure up to 15psi.
I very seldom have to clean the lens, and have never had any flareup problems. I do have a small water seperator on line, never have had any water in it.

My first system worked like that from the factory, my 2nd system did have a few problems at first until I found a plugged line leading to the final lens. Opened that up and works great.

Some will say this does not work, but it does for me. And the best part is I can run them all day and they can not be heard over the laser.

[Scott Shepherd]

Paul, part of the reason why it probably works for you is your location. Humidity isn't a problem there, is it? We get 80% humidity days here and moisture seems to form anywhere and everyone that cool (or hot) air is coming through.

[Bill Cunningham]

I use a home made filter made from 6 feet of 1.5" Galv. pipe and end caps, (Drain at the bottom, and welded input at the side about 3" from the bottom) and 1/4 filled with a layer of marbles (at the bottom) a screen and a felt pad and a column of Molecular Sieve 13x which absorbs water and C02..then a screen and felt before the discharge. The missing CO2 makes no difference to the laser, it's just the other thing removed by the molsieve.. The marbles take the brunt of the 'big' water by presenting a much larger surface area than could otherwise be obtained, and prevent raw water from contamination the sieve.. Ahead of this filter, I just use a normal inline filter to remove oil.. When the dew point goes up on the filter, you can put the the molsieve back in the original can it came in and set it in the oven for a hour or so to bake it out and re-activate it.. The only thing that will kill the molsieve is oil..