I am sure the experience base here exceeds anywhere else on the net. Lightburn has replaced Photoshop as my favorite, most powerful software for my business application.
Just replacing my 10 watt diode with an extended bed 20 watt for an upcoming production run in my leather business. I have not found any air assist pumps that exceed 30 l/m. I thought of testing my airbrush compressor which will manage 80 lbs BUT is only 20 l/min. My Harbor Freight 150 lb compressor is oil based and the thought of spraying a fine film of oil on my laser lens doesn’t thrill me.
Has anyone tested higher pressures through diode air assists to see if there’s any benefit over 30 l/m?
Thanks!
Bob
I engrave only on my dpssl lasers, however I use 60lbs when I cut most mdf with my co2… have no clue what l/m it relates to. Do you know the pressure?
I had a lower pressure model from harbor freight and run with it over 6 month period with no issues from the oil…
You should expect your lens to be dirty after a job and ensure it’s clean before you run the next job… within reason, so to speak… Haven’t noticed any difference as to when the lens got dirty… If the machine is running, it’s low pressure air is operating.
I have a ultra quiet with a 20gal tank.
You will have to figure it out examining the resultant cut.
Thanks…different worlds. I inspect my lens monthly and clean less often. There is no relation between volume and air pressure. 60lbs at 30 l/m is very different from 60lbs at 15 l/min. My airbrush compressor will product 80 lbs or more but no more than 23 l/m so useless for air assist. Maybe your oil compressor is the reason you have to clean after every job?? That’s why aquarium type pumps are used for air assist…not nice to kill the fish or the lens.
Bob
Well I used an oil compressor at about 2 to 8 PSI and it is brilliant But it is bloody noisy even in the workshop next door…
So purchased a sculpfun 30 L/m air pump on line and find it useless ( I was cutting 3mmMDF in 1 pass with air pump 2 plus passes) ,changed back to the compressor and back to 1 pass…
On another note when I ordered the air pump I was thinking and looking around for the cheapest deal and I had a medical problem with my heart and when I got back to ordering the pump I forgot that I had ordered it and now I have to useless pumps at 130NZ dollars each… Bummer plus…
On my machine, I have multiple nozzles, so figuring volume is rather useless… You can put lots of pressure, but have no clue how much volume a minute I use a when I’m doing it.
The air purge scared the peedadle out of my dog… Ended up making a muffler.
Keep in mind that most “shop” type piston air compressors are rated in CFM (cubic feet/minute)
1 cubic ft is about 30 liters and shop compressors are typically double this or better, but it is good to check before buying.
Also of use with any compressed air source is a good filter/dryer. These remove airborne crud and moisture (water/oil) and are often paired with a pressure regulator.
I’ve got a little hole in one nozzle and a larger one on the other… I run a certain pressure…
How do you convert to make it usable?
10mm ID is about 12mm OD… unless this runs to the head, it’s of no help… probably moot there also…
It’s only really reasonable to purchase something that is the same size as the smallest orifice in the system. If you run a huge line there and it goes through a small hole… what have you gained.?
I know of no one, when asked about his air assist, they respond with l/m…
I recently purchased a 20 Watt Atomstack with air assist and an extended bed. My initial tests produced poor results, with lots of smoke damage and charring with the compressor running at 30 l/m
On closer examination, the pot metal nozzle had an air inlet of around 1.5 mm and the end of the inlet, into the nozzle had a diameter of less than a millimeter. I was not able to poke a tooth pick through the orifice it was that small. I slowly and carefully drilled out the inlet and orifice to 3mm. The OD was 6mm and I contacted the company and explained the situation and stated that a 20 watt laser was useless w/o a working air assist. I asked them to provide a few extra nozzles ($0.25 ea. ?) to test and see how big I could open the air inlet up without breaking through. In addition, the back was completely open and half the ai or more was blowing out the back. I created a disc with a hole for the laser that was an exact fit for the nozzle resulting in 100% of the air exiting through the nozzle. They couldn’t be bothered and said they were just the distributor, contact the factory. The factory said they were not the sellers, contact Amazon. So I did, and returned the POS. Wouldn’t touch Atomstack with a 10 foot pole.
Bob
It’s only really reasonable to purchase something that is the same size as the smallest orifice in the system. If you run a huge line there and it goes through a small hole… what have you gained.?
That’s not actually true, only for a 1 inch tube but you will have air resistance induced in a long run of small gauge and consequently deliver less air to the actual nozzle. My rule of thumb, for normal runs, is matching the ID of the tubing to the OD of the inlet to the nozzle.
I follow… I don’t think the air resistance is significant with a tube that is 6mm… the hole it goes through is even smaller…
If I have my 60lbs at the input to the head, that’s about the best I can do…
How do you know how much volume is running…? Do you have instruments to measure this?
What kind of pressure did the machine produce… before you returned it…?
These nozzles are junk anyway… If you follow some of the really functional machines the air is actually formed into a stream so it assists with the cut…
I do mostly engraving… so I’m happy with the way mine works…
All I’m saying, is I’ve been doing this a number of years and every now and then someone starts talking about l/m… Everybody here uses pressure gauges …
Which seemed like a good idea for calibrating the dual-flow plumbing:
I’ve been running 2 l/m for engraving and 12-14 l/m for cutting, with the higher flow limited by the piddly air pump. Both seem to work well, so I’m happy.
Other folks seem happier with gale-force winds, so there’s obviously a time for every style.
So what does that tell you as far as what’s happening at the nozzle?
I’ve only been exposed to a couple of industrial lasers, it’s done with pressure, not volume…
I guess I understand how pressure works, but I can’t see how I would relate volume to the 30 pounds of air pressure I want on the target… without a bunch of math on hydrodynamics.
Not that it really matters… you would really have to know the pressure inside the nozzle.
l/m seems to be the norm in Diode lasers, keeping in mind that only recently have the most powerful diodes start to approach the least powerful CO2 lasers. For my application, 10 watts is plenty and 20 is overkill. My issue is staining and charring and keeping the lens clean.
I would tell you what I really think about the quality/reliability of the AS Air Assist but I don’t want to be banned.
The air assist is easily at least upgraded and I had designed and 3D printed a upgraded replacement but the lack of support and attitude from Atomstack was not.
The flow meter tells all, because the only thing that matters with assist air is how much of it flows through the nozzle around the beam. The nozzle diameter certainly affects the air speed, but flow determines how much air gets to the scene.
Air flow is powerfully nonlinear with tubing ID / length / fittings / whatnot, so your 30 psi compressor definitely doesn’t deliver the same flow as my 30 psi compressor. If, that is, I had a compressor instead of a piddly air pump that might be good for 3 psi on a good day with a stiff tailwind.
It’s pretty much why you have an optical power meter: tube current isn’t a good measure of beam power. Your new 43 W tube probably delivers the same beam power as my old & overcranked “60 W” tube at, say, 15 mA, but without aiming mine at a power meter, we’ll never know. (Which is another project, dagnabbit!)
I was tempted to pick up a flow meter but most of them are too low capacity…mostly used for 02 applications and as a scuba diver I know that 30l/m of 02 and you’ll be probably doing the funky chicken in no time! (O2 Toxicity). A way of comparing flows is blowing into a graduate (no jokes please) and checking the level of air displacement. I would say that air speed vs Air quantity requirement is a function of laser speed. Most diode lasers are are crawling along during cutting and that may be a more volumetric demand.
