How much air?

[AndyKunz]

How much air pump do I need? CFM? PSI?

I am building a 900x600 with 60W laser and plan to cut up to 1/8" birch aircraft ply.

Thanks.

Andy

[NickWL]

I'm using a double piston airbrush pump on my modded K40: 1/4HP, 35-40 litres/minute, 3.5l reservoir.
It isn't man enough! Well, it just about copes, but the pump seems to be running almost continuously which is a pain in the eardrums.
Try for something about twice this size (I reckon).
Nick

[MitchL]

Nick,

Wow, that's a big pump-- maybe I'm missing the purpose of the air assist -'I thought the idea was just to keep positive air pressure on the lens so that it didn't get any of the vapors from cutting.

So, I just use a little harbor freight airbrush pump, no reservoir. It's small and quiet.

Other than dirt on the lens, does the air assist do anything for cutting? Remember I'm trying to figure out why my 80w laser can't cut 3mm acrylic. I didn't think air assist pressure would have anything to do with that.

Mitch.

[NickWL]

I suspect you're right and I'm wrong, though I do sometimes have to turn it up quite high to extinguish flames when I'm cutting things like plywood - that's when the pump goes into full-time mode.

[AndyKunz]

So, I just use a little harbor freight airbrush pump, no reservoir. It's small and quiet.

I e-mailed a friend who has a cutting business, and he said he uses a Harbor Freight airbrush pump too. He complains about it being loud (my HF pump is loud) and that the laser he has specs 30 PSI but not CFM.

Is yours like this? http://www.harborfreight.com/1-5-hp-58- ... 95630.html

This is what I have already: http://www.harborfreight.com/3-gal-13-h ... 69269.html

I'm not really big on noise if I can avoid it, so if I can find something quieter than I have (super fish-tank air pump) I'd spend money to avoid it, but not too much money.

Andy

[AndyKunz]

On the same subject of air, is http://www.lightobject.com/Pneumatic-8m ... -P609.aspx the correct part to get to attach this air line http://www.lightobject.com/5X8-Silicon- ... -P776.aspx to the laser head on my 900x600?

Andy

[MitchL]

Is yours like this? http://www.harborfreight.com/1-5-hp-58- ... 95630.html

Yes, that's the exact model that I'm using. I modified it to use a standard quick-connect and attached it to my laser.

I think it's really quiet -- the fan in the laser power supply is noisier, and there's background noise from the chiller. I expect the loudest noise during laser jobs will be the exhaust fan.

You can hear the air assist in these videos of test jobs (my machine's not quite done yet). I don't have any exhaust set up yet, so all you hear is the air assist, laser PSU, and chiller.

https://www.youtube.com/watch?v=wkN56l7P8yo
https://www.youtube.com/watch?v=NM8laxRoUfo

/Mitch.

[NickWL]

Mine is similar to that but with two cylinders and just a bit more poke.
The noise is not extreme but is still very annoying (at least it is to me!).

[greg_gran]

How about just using a commercial O2 aquarium pump from Elemental Solutions? They come in 5 different sizes from 20 watt to 120 watt (36 to 110 liters/min). They range in price from $30 to about $70 w/free shipping on eBay. This is exactly the same type of air pump that Lightobject normally sells (currently out of stock). They are designed for continuous duty - I don't think the airbrush pumps are. Noise level isn't that bad - kind of a moderately loud hum.

[AndyKunz]

How about just using a commercial O2 aquarium pump from Elemental Solutions? They come in 5 different sizes from 20 watt to 120 watt (36 to 110 liters/min). They range in price from $30 to about $70 w/free shipping on eBay. This is exactly the same type of air pump that Lightobject normally sells (currently out of stock). They are designed for continuous duty - I don't think the airbrush pumps are. Noise level isn't that bad - kind of a moderately loud hum.

Thanks, that was a great suggestion. I just ordered one from Allied Aqua on ebay.

Andy

[greg_gran]

How about just using a commercial O2 aquarium pump from Elemental Solutions? They come in 5 different sizes from 20 watt to 120 watt (36 to 110 liters/min). They range in price from $30 to about $70 w/free shipping on eBay. This is exactly the same type of air pump that Lightobject normally sells (currently out of stock). They are designed for continuous duty - I don't think the airbrush pumps are. Noise level isn't that bad - kind of a moderately loud hum.

Thanks, that was a great suggestion. I just ordered one from Allied Aqua on ebay.

Andy

When I bought mine, I got the largest one. However after getting it hooked up, I realized that it was overkill and that one of the smaller ones would have probably worked just fine.

[AndyKunz]

When I bought mine, I got the largest one. However after getting it hooked up, I realized that it was overkill and that one of the smaller ones would have probably worked just fine.

I got the 1268gph one for the same reason. If I find it overkill, I'll mention that in my build thread (and probably here too). I based my decision on LO's being 1500-ish gph.

One thing I'll be adding is at least 2 stages of filter/dryer.

Andy