Noobie Question - Exhaust System

[Joe Kace]

Hello All,

Well I am new to lasering and I have a question. Do you have to have the exhaust on when engraving marble or granite?
Thanks in advance.

Joe

[Viktor Voroncov]

Of course, as during engraving you have small but hard stone dust. This dust can left on moving parts and damage them due abrasion. My advice have powerful AIR ASSIST and EXHAUST if you work on stone.

[Joe Kace]

Thanks, just what I thought. I have a 850cfm blower and air assist.
Thanks for the reply

Joe

[Gary Hair]

I'm going to disagree with the air assist - you don't want to blow that dust all around, you want to suck it out the exhaust. I always use exhaust but only really use air for cutting.

Gary

[Dan Hintz]

As with Gary... exhaust, yes, air assist, no.

[Joe Kace]

Ok.. Air assist no, got it. Good, to much power running in my shop as it is. I always use AA when cutting but wasn't 100% on the stone end. Thanks to all who responded.

Joe

[Joe Pelonio]

I use air assist only for cutting. The exhaust pulls from the back and all the engraving is towards the front from there, so it's constantly sucking the dust away from the optics.

[Gary Hair]

I use air assist only for cutting. The exhaust pulls from the back and all the engraving is towards the front from there, so it's constantly sucking the dust away from the optics.

And on the same subject - I do raster from the bottom up on almost everything. That way I'm not sucking the soot and smoke back over the place I just engraved. I have way less cleanup to do this way.

Gary

[Viktor Voroncov]

Use of air assist depend from engraver construction. All my customers (GCC lasers) use air assist for stone engraving.

[Gary Hair]

Use of air assist depend from engraver construction. All my customers (GCC lasers) use air assist for stone engraving.

Viktor,
I have a GCC Explorer and would NEVER use air assist with stone engraving. All you are doing is blowing the grit around inside the laser and into the bearings. I hope you'll reconsider advising your customers of this unless your intent is that their greasy bearings are full of grit and you can sell them new rails and blocks when they have worn out prematurely...

[Viktor Voroncov]

Gary, my customers (over 20) use air assist during stone engraving. As you can see on your laser - exhaust hole is located below engraving surface. Air assist move dust from engraving area to the border areas of table and after exhaust extract dust from laser. There is only one important thing - exhaust schould have enough power to effective remove dust.
There is no dust on bearings/other moving parts if air assist/exhaust is made properly. I will take pictures tomorrow from my customers location to explained what I mean.

[Joe Kace]

Ok.. I think I will go with no AA. I have read some other sites and they say no AA with stone, but to each his own I guess.

Joe

[Richard Rumancik]

Joe, it depends on the laser construction - I don't know what model you have. On the Mercury I use air assist for everything to protect the lens. Air assist pressurizes the lens compartment so nothing can fly up into the lens and vapors cannot deposit on the lens.

You don't have to set the pressure so high that it is blowing stuff around. It just needs to be a couple psi to ensure that the pressure is higher than ambient below the lens. Viktor suggests "powerful" air assist but personally I would tend to use the minimum.

Other models have open lenses, and in this case air assist will do nothing to protect the lens.

[Joe Kace]

Richard,
I have a Epilog Helix 40w with a 850CFM Exhaust blower. I have the AA pump that came with the machine from Epilog.

Thanks

[Richard Rumancik]

Joe, the Helix (and all the Epilogs I believe) has the final mirror and lens out in the open. So air assist can't do much to protect anything from bouncing back onto the lens. I do like the fact that GCC puts their final mirror and lens in a small enclosure. More like what they do for industrial lasers, where the assist gas is blown from a conical aperture in front of the lens. So in the case of the Helix, air assist probably won't be a benefit for stone.