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Brian Leavitt
03-09-2015, 11:39 AM
I typically clean my laser optics on a weekly basis, unless I'm running a lot of glass, which requires more frequent cleanings. Well, the one time I forgot...

http://i.imgur.com/n35EkjVl.jpg
http://i.imgur.com/GUFskt7l.jpg

Scott Shepherd
03-09-2015, 11:51 AM
Ouch, looks like it started frying the mirror too :( Hopefully you can save the mirror.

Jeff Belany
03-09-2015, 11:58 AM
What were you lasering that caused that? Luckily mine have never got that bad. Curious -- I never thought of glass being a 'dirty' product to laser. Wood and acrylic cause me the most issues.

Jeff in northern Wisconsin

Mike Null
03-09-2015, 12:10 PM
I examine my lens daily. No replacement in nearly 18 years. Cermark gets a lens dirty in a hurry.

Mike Lassiter
03-09-2015, 12:31 PM
Brian were you doing raster engraving by chance?
I was engraving ceramic tile about a year ago to try color filling and running full power (135 watts) and realatively slow speed and had something like the pictures happen. The tile was popping (?) and I didn't think too much about it until trying to cut 1\4" mdf afterwards and that went very poorly. Wide burn mark instead of cutting. My lens looked similar but maybe wasn't black as yours but a dark brown. I think a fragment of tile popped up and hit my lens cracking it. Then the lens absorbed heat from the beam and became very hot (very quickly too with full 135 watts in use) and started discoloring.
Just curious if similar situtation with you. My lens was not damaged before the ceramic tile, as I had changed to it before doing the tile. Pretty sure the lens got damaged by popping fragments of the tile then the lens began absorbing heat from the beam afterwards in my case.

I typically clean my laser optics on a weekly basis, unless I'm running a lot of glass, which requires more frequent cleanings. Well, the one time I forgot...

http://i.imgur.com/n35EkjVl.jpg
http://i.imgur.com/GUFskt7l.jpg

Clark Pace
03-09-2015, 8:33 PM
Wow. I look at my optics doing job that requires i turn off air assist. I also do routine machine cleanup including lubing the gears about once a month. But i do look at my optics often.

Keith Colson
03-10-2015, 4:19 AM
My air assist is always on. The only thing that comes off is the nozzle and that's only for Cermark and synthetic wood engraving. My lens barely gets dirty. Those lens/mirror units here in New Zealand are about 1000 bucks so I am really trying to avoid buying another one.

Scott Shepherd
03-10-2015, 9:13 AM
My air assist is always on. The only thing that comes off is the nozzle and that's only for Cermark and synthetic wood engraving. My lens barely gets dirty. Those lens/mirror units here in New Zealand are about 1000 bucks so I am really trying to avoid buying another one.

Are you saying you use engrave the cermark and synthetic wood with the nose cone off and the air on? If so, that's a sure fire way to break a lens. That's a known no-no so be careful, especially when you are looking at $1,000 to replace them in your country. It essentially create a vacuum and sucks debris up into the lens cavity. I've witnessed it many times. I'll walk by a laser, typically when someone new is using it, watch it cut and immediately notice something is not right. I look, the nose cone is off, the air is on. It'll fog up the optics in a very short period of time, so be careful.

Brian Leavitt
03-10-2015, 2:16 PM
Ouch, looks like it started frying the mirror too :( Hopefully you can save the mirror.
The mirror is actually fine, thankfully. By the time I noticed something was amiss with the laser, the lens was smoking and some of the smoke residue got on the mirror. It wiped right off, though.

Brian Leavitt
03-10-2015, 2:19 PM
What were you lasering that caused that? Luckily mine have never got that bad. Curious -- I never thought of glass being a 'dirty' product to laser. Wood and acrylic cause me the most issues.

Jeff in northern Wisconsin
I think I was running acrylic awards when I noticed, but I was doing glass awards before that. When I do glass, it creates a very fine white powder that clings to everything, which is why I typically clean the lens after running glass.

Brian Leavitt
03-10-2015, 2:25 PM
Brian were you doing raster engraving by chance?
I was raster engraving. I think it started to bake when I was running a glass award because the engraving didn't come out as clean as it typically does. I didn't really notice that there was an issue with the lens until the next job I was running. I nocited the engraving on the acrylics was getting lighter, and then nonexistent. Then I noticed the lens carriage was smoking! I don't think anything hit the lens. I believe it was simply because I had forgotten to clean it and it developed a layer of glass powder on the lens. I am typically on the ball with keeping the optics clean. This is the first time in fifteen years of lasering that I have had a lens go bad.

This machine (X2-600) does not have air assist.

Chad Fitzgerald
03-10-2015, 3:38 PM
You got me very curious..... GLASS being dirty???
I have never noticed anything when engraving glass. Never check optics after engraving glass either. Am i just lucky or not paying close enough attention????
Thoughts??
CHad

Brian Leavitt
03-10-2015, 3:51 PM
You got me very curious..... GLASS being dirty???
I have never noticed anything when engraving glass. Never check optics after engraving glass either. Am i just lucky or not paying close enough attention????
Thoughts??
CHad

This is what I get, and have always gotten, when doing glass. This is running at 80 power and 30 speed on 50 and 60 watt lasers. I know some people say you shouldn't even need to use air extraction when doing glass, but in my experience, this is not the case. This dust gets on the lenses, belts, I-beams, etc.

Chad Fitzgerald
03-10-2015, 4:02 PM
wow, that is wierd. i think. thanks for showing the pic so i could see what you meant. nope, never have seen anything like that from glass. hmmm
chad

Paul Phillips
03-10-2015, 4:46 PM
Brian , does your machine not have the option to use air assist or do you not have it hooked up? Might be worth setting it up to use air assist if you can, there might be a kit you can purchase to retro fit it if you don't have it, there's a reason it comes as standard equipment on newer lasers, and would IMO solve the dirty lens problem.

Brian Leavitt
03-10-2015, 5:00 PM
My Unversals did not come with air assist. The Epilog has it, and it gets used regularly. I do believe there is a retrofit kit available for the X-series ULS machines, but it ain't cheap. For the time being, at least, I'll just continue my regular cleaning procedures (and trying real hard not to forget again) as they have worked well for many years. I do really like the air assist on the Epilog, though. Would like to add it to the ULS lasers some day.

Dan Hintz
03-10-2015, 5:20 PM
This is what I get, and have always gotten, when doing glass. This is running at 80 power and 30 speed on 50 and 60 watt lasers. I know some people say you shouldn't even need to use air extraction when doing glass, but in my experience, this is not the case. This dust gets on the lenses, belts, I-beams, etc.

That's definitely a new one on me, Brian, and I've done a lot of glass in the years gone by. One side note... make sure you're optics are free of any oils, as those will trap contaminants like no tomorrow, and then it dominoes. I'm not really sure where you're getting such a fine powder from, but I do have my doubts it's from glass (possibly something on the glass that is off-gassing).

Also, those numbers are WAY high for glass. For my old 60W ULS, I was at 100S/60P for float glass. I don't know what speed the older X-6xx ran at, but if they were close to the 75ipm of today's ULSs, you may be creating more problems for yourself. Once the glass fractures, pouring more heat into it only causes problems.

Bert Kemp
03-10-2015, 5:32 PM
I run air assist 99% of the time. The only time its off is if I have the air cone off for some reason OR I'm using powder coat as a fill. Air blows this stuff all over the place:D


My air assist is always on. The only thing that comes off is the nozzle and that's only for Cermark and synthetic wood engraving. My lens barely gets dirty. Those lens/mirror units here in New Zealand are about 1000 bucks so I am really trying to avoid buying another one.

Hilton Lister
03-11-2015, 6:24 AM
I invariably get residue on my lens when engraving glass, but then I always use a detergent mix when doing it. I now rinse the lens in running water after I have finished, as I feel that the residue scatches if it
removed with alcohol and a cotton bud as is usually recommended. And yes, I do use air assist.

Brian Leavitt
03-11-2015, 10:42 AM
That's definitely a new one on me, Brian, and I've done a lot of glass in the years gone by. One side note... make sure you're optics are free of any oils, as those will trap contaminants like no tomorrow, and then it dominoes. I'm not really sure where you're getting such a fine powder from, but I do have my doubts it's from glass (possibly something on the glass that is off-gassing).

Also, those numbers are WAY high for glass. For my old 60W ULS, I was at 100S/60P for float glass. I don't know what speed the older X-6xx ran at, but if they were close to the 75ipm of today's ULSs, you may be creating more problems for yourself. Once the glass fractures, pouring more heat into it only causes problems.
I do appreciate the input, Dan, but I must respectfully disagree on the power/speed settings. I have tried different settings in the past and if I try increasing the speed, or reducing the power, the quality of the etch degrades. These settings have always given me the best quality of engraving. Also, I'm running it at 300ppi as opposed to the 500ppi I use for most everything else. In fact, the ULS recommended settings are 100 power and 23 speed for the 50 watt machine on which I typically run glass. None of the settings I use for any of the materials I run were determined without much testing in the real world.

Bill George
03-11-2015, 11:59 AM
I do appreciate the input, Dan, but I must respectfully disagree on the power/speed settings. I have tried different settings in the past and if I try increasing the speed, or reducing the power, the quality of the etch degrades. These settings have always given me the best quality of engraving. Also, I'm running it at 300ppi as opposed to the 500ppi I use for most everything else. In fact, the ULS recommended settings are 100 power and 23 speed for the 50 watt machine on which I typically run glass. None of the settings I use for any of the materials I run were determined without much testing in the real world.

RF tubes are spec'd to put out at least the rated output, many new and rebuilt ones exceed those ratings. As the tube ages and they all do at different rates, your settings will also need adjustment.

Dan Hintz
03-11-2015, 12:28 PM
I do appreciate the input, Dan, but I must respectfully disagree on the power/speed settings. I have tried different settings in the past and if I try increasing the speed, or reducing the power, the quality of the etch degrades. These settings have always given me the best quality of engraving. Also, I'm running it at 300ppi as opposed to the 500ppi I use for most everything else. In fact, the ULS recommended settings are 100 power and 23 speed for the 50 watt machine on which I typically run glass. None of the settings I use for any of the materials I run were determined without much testing in the real world.

I typically run glass at 250-333dpi. I know what ULS recommends (100P and speed = wattage, so 50W = 50S) and I found it to be WAY too hot. If you're happy with what you have, that's all that matters, but I'd urge you to try again with a much lower power level and see if you can get it to work. If nothing else, it would speed up your work. Of course, my suggestion only rings true if your older systems are running at the now-standard 75(ish)ips. If your machine is slower, you could get away with even less power than I recommended earlier.

Bill Cunningham
03-12-2015, 10:25 PM
I etch lots of glass, and I clean my lens about once a week, and have for the last 11 years. I also never use air assist with glsss. Still running the same lens I got with the machine. I don't think the Epilog open lens setup is as prone to collecting crud as some others.

Chuck Stone
03-13-2015, 1:04 AM
I get that fine dust too when I engrave glass .. SOME glass. Not all.
But I always get it when I engrave Corian. TONS of it!
And even with the air assist, it somehow manages to get past the
cone and up into the lens area