Knackered my Trotec Speedy 300 lens!

[Mark Ward]

Managed to completely knacker my lens up by cutting some cardboard for 2 minutes yesterday, black mark burnt into the middle of the lens that won't shift and has stopped the laser working properly :mad:
Used the Trotec settings for Cardboard too (first time ever) in the Job Control so well and truely off as I just can't understand how or why it has caused this damage! :mad:

Anyway, quote for a replacement 2,0" lens is £245.94 including the postage ($406) :eek:

I was thinking it would be nearer to £100. Very expensive this!

[Dan Hintz]

Used the Trotec settings for Cardboard too (first time ever) in the Job Control so well and truely off as I just can't understand how or why it has caused this damage! :mad:

Was air assist on and did you have good extraction flow? The settings alone won't cause a scarred lens, the lens had to be collecting soot.

[Mark Ward]

Was air assist on and did you have good extraction flow? The settings alone won't cause a scarred lens, the lens had to be collecting soot.
Have just looked and the default in JobControl for cardboard is Air Assist off :(
I genuinely didn't even think to look at this as we've not done cardboard before and it was a very quick one off job so took faith that Trotec would have set a safe set of defaults for it. Ultimately I know it is my machine and me that set the job to go, I just genuinely didn't think the default settings for a one off 2-3 minute job on cardboard could be so damaging!
Extraction flow was very good.
Live and learn!

[Scott Shepherd]

it was a very quick one off job so took faith that Trotec would have set a safe set of defaults for it.

The settings were right, it cut just fine. The problem is you had the nose cone on and the air off. There's no way for the software to know if you forgot to take the nosecone off. When you leave it on with the air off, it creates a vacuum and sucks the debris right into the lens.

[Jason Hilton]

Is there ever a good reason to not use air assist when cutting? I know when I was using epilog at the makerspace I'd turn it off when doing certain engraving, but I'd think that any cutting job would benefit from air assist?

[Mike Troncalli]

I don't know if I have ever NOT turned my air assist on. I have my Water pump, air assist and exhaust fan hooked up to a switched power strip. It is just old habit for me to hit switch 1 "Water Flow" first and then right before starting the job I hit switch 2 and 3... I have them in this order so that I can first "hear" the water pump (I don't have a visual flow window). Then I hit switch 2 so that I can hear the air assist compressor, after that switch 3 which is the exhaust (it is of course the loudest)..

[Bill George]

Its a glass lens, correct? With some carbon burnt on it, I can't believe that it can't be cleaned off with some solvent and re-used. No scrubbing just soft cloth. Even soaking in soapy water would soften I would think.

[Mark Ward]

The settings were right, it cut just fine. The problem is you had the nose cone on and the air off. There's no way for the software to know if you forgot to take the nosecone off. When you leave it on with the air off, it creates a vacuum and sucks the debris right into the lens.
That is the problem. I always leave the nose cone on and always have the air assist on for all the jobs I've done, however, I just presumed (wrongly) that the trotec settings would by default have the air assist on with the cardboard as it is the only time I've used that setting (I didn't check foolishly) for the cut which unfortnately they didn't, my fault for quickly rushing and not checking but it didn't even cross my mind :(

Its a glass lens, correct? With some carbon burnt on it, I can't believe that it can't be cleaned off with some solvent and re-used. No scrubbing just soft cloth. Even soaking in soapy water would soften I would think.
I've left the solution soaking in it and it won't shift, even picking with my nail doesn't budge any of it. Will post a picture up later.

[Bill George]

Wonder if an Ultra Sonic cleaner would work and not damage the lens?

[Kev Williams]

Soak the lens in oven cleaner, if that doesn't work nothing will. And it shouldn't hurt the lens itself.

[Paul Phillips]

I feel your pain Mark, I had to learn the hard way also, this has been discussed many times on this forum, new users take care! Steve has the right idea, air on, cone-on, air off, cone-off! REMEMBER THIS RULE!
http://www.sawmillcreek.org/showthread.php?201881-Help-with-Cracked-Lens&highlight=cracked+lens+uls

[Jiten Patel]

Mark, read this post http://www.sawmillcreek.org/showthread.php?205561-Have-I-messed-up-my-lens-already

I did the same thing, probably a built up on the lens already. I did it cutting MDF and by default, air assist is off when you create a new profile in job control. I managed to get it off with about 30-40 minutes of gentle scrubbing - treat it like a woman and if should come off - nice and gentle and lots of patience!!!!

[Dan Hintz]

Its a glass lens, correct? With some carbon burnt on it, I can't believe that it can't be cleaned off with some solvent and re-used. No scrubbing just soft cloth. Even soaking in soapy water would soften I would think.
Zinc Selenide, but you can very quickly destroy the AR coating on it with scrubbing. You can't treat these lenses (or mirrors) like a piece of glass in your house's storm door.

Soak the lens in oven cleaner, if that doesn't work nothing will. And it shouldn't hurt the lens itself.

Gees, really, Kev? :eek: Oven cleaner? That'll strip the AR coating off in a heartbeat.

[Bob A Miller]

Mark, I too feel your pain... I just screwed up two of them last week... Obviously I tried a few things the second time around but the recommendation didn't work... I have gone to a 2.5" lens & rebuilding my air system. To compound things when I did have it up & running the job control software would stop in the middle of a job. Finally caught it saying "internal application error". Trotec technical support told me older laptops running the 15' supplied USB cable can have a voltage drop off that is enough to do that. So now have a 10' cable.

So I have been reading the cleaning ideas & will report back on that, now having ample opportunity to practice. Just not sure about giving the oven cleaner a try. Going to start I think with simple green. That works as a gentle organic paint remover.

Cheer up you aren't in this alone. For the record the replacement 2" lens was 410 can$ after tax.

[Keith Colson]

One great stain removing method is to simmer the lens in glycol (green anti freeze) in a pot on an outdoor stove for about 24 hours. If that does not work then the last thing you can do is polish the lens with some glass polish. This takes a layer of glass off and will leave you with imperfect focus but probably good enough for a lot of jobs. Either way you go, your lens coating is prolly stuffed.

My air assist is always on and the machine will not run if it's off. The only thing I do is turn down the pressure when doing metal engraving. It may not be the best thing to do but I do think it is the safest thing as I am bound to forget otherwise.

Good Luck
Keith

[Mark Ward]

I'll have a go at treating it like a woman then Jit. Bryan at Trotec said I could send it him to have a look at too but I think it's probably past repair.

I have just had a new lens delivered from Trotec, the holder for this one is a metal one as apposed to the black plastic holder on our old one. I presume that this is just an updated holder rather than it meaning it's a different focus, I did ask for the 2,0" lens so I'm presuming I don't need to do anything other than stick this new lens straight in and start working or do I need to do any sort of re-focusing or anything (I don't imagine so?).

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[Dan Hintz]

Do NOT use oven cleaner... sheesh, you guys are treating Ferraris like disposable Yugos! Use the proper cleaning solution for your lens and mirrors so we don't have to hear your tale of woe a year from now how the power output seems to have dropped or your focal point isn't as sharp as it used to be. At the very least, go to your local liquor store and pick up a bottle of Everclear... if you don't use it on your lens, take a swig or two for your own sanity (and mine!).

[Mark Ward]

Do NOT use oven cleaner... sheesh, you guys are treating Ferraris like disposable Yugos! Use the proper cleaning solution for your lens and mirrors so we don't have to hear your tale of woe a year from now how the power output seems to have dropped or your focal point isn't as sharp as it used to be. At the very least, go to your local liquor store and pick up a bottle of Everclear... if you don't use it on your lens, take a swig or two for your own sanity (and mine!).
Oven cleaner hasn't been touched :)
I'll have another go with the proper cleaning solution but don't think it will make much difference.

Just to check, my new lens am I OK to just stick in and work away or does it need any sort of fettling. Looking at the box, it looks like the stats on this new one are 2,01mm and on the old one the box says 2,03mm, unsure if that will make any difference. I guess if just trying it out won't harm it I can just run a small job and see the results.

[Mark Ward]

Right, just run a test job and the lens/laser clearly needs to be re-fucussed as it has done a terrible job. I've searched and can't find a guide anywhere as to what to do, can anyone help as I've got a number of jobs I need to get done today and currently can't do any!:(

Just to add, I'm using the focus tool like I always have to position the height of the bed from the laser.

Also, is the silver casing of my lens (instead of black) a likely mean that it might be the wrong lens?

No answer from Trotec support is why I'm peppering the questions here at the moment!

[Keith Colson]

As far as I know there in only one adjustment and that's the height off the table. If your focus tool is not right then that means you have a different focal length lens now. If you want to empirically find the focus you can do it by trial and error. I use this pattern in raster mode for checking focus. 0.2mm to 0.5mm spacing and line width.
295642
The horizontal will always have more error due to the rastering process (backlash etc). For your z height concentrate on the vertical error. Someone else may have a better solution but it sounded like you want to get going "now"

Cheers
Keith

[Mark Ward]

As far as I know there in only one adjustment and that's the height off the table. If your focus tool is not right then that means you have a different focal length lens now. If you want to empirically find the focus you can do it by trial and error. I use this pattern in raster mode for checking focus. 0.2mm to 0.5mm spacing and line width.
295642
The horizontal will always have more error due to the rastering process (backlash etc). For your z height concentrate on the vertical error. Someone else may have a better solution but it sounded like you want to get going "now"

Cheers
Keith
Thanks for the quick reply Keith. I think they have sent me the wrong lens then as I was using the focus tool and not only is the holder a silver metal rather than the black plastic that the previous one was but the engraving/cutting as it is a country mile off even being close which 2 lens should be in a similar ball park at least.

Thanks for that possible work around, I may have to give it a go, although I'm hoping I might be able to go to a local(ish) Trotec showroom and run my jobs there, waiting for a call back now :(

[Mike Null]

I believe in some previous posts Gary Hair may have suggested that inclining a piece of anodized aluminum on the table then running test patterns on it might help determine the focal length. A search should turn up a couple of threads on the topic.

Mark

I believe the holders are color coded and a recent post identified the colors. I think it was Steve Shepherd who posted it. The two inch lens should have a black holder.

[Scott Shepherd]

Also, is the silver casing of my lens (instead of black) a likely mean that it might be the wrong lens?



Mark, you are correct, that's the wrong lens. As Mike said, the black is 2.0", the silver is 2.5". I just measured the focus tool for the silver one and it's about 12mm longer (further away) than the black one. Put the silver one in, focus it, then look at your z value in Job Control (there's an X,Y,Z value that's real time) and just lower the table by 12mm.

That will get you running until you can get things sorted out.

[Martin Boekers]

This is a long shot, but try taking the lens to a camera store and see if they have any recommendations....

[Mark Ward]

Mark, you are correct, that's the wrong lens. As Mike said, the black is 2.0", the silver is 2.5". I just measured the focus tool for the silver one and it's about 12mm longer (further away) than the black one. Put the silver one in, focus it, then look at your z value in Job Control (there's an X,Y,Z value that's real time) and just lower the table by 12mm.

That will get you running until you can get things sorted out.
Top man, this is what I did, had to switch the nose cone out for the larger holed one too. Managed to get the jobs done to more an acceptable level in the end and hopefully Trotec send the correct lense out tomorrow!

[David Somers]

Hmmmm. Listening to folks talk about knackering lenses left and right made me wonder exactly how many spare lenses it is wise to have on hand. Needless to say I am talking about Chinese machines where lenses are not as expensive as a Trotec's, and where at the time of your initial order the weight of extra lenses is not going to impact your shipping costs.

Dave

[Bob A Miller]

Dave... When I got my Chinese machine I got a spare lens in every size.... Never used one if them yet. The Trotec, exactly the opposite.. Go figure.

[Mike Null]

I have been in the business for 17 years using a ULS and now Trotec and have never replaced a lens. Nor have I ever had a spare. (KNOCK ON WOOD)

[Gary Hair]

I have been in the business for 17 years using a ULS and now Trotec and have never replaced a lens. Nor have I ever had a spare. (KNOCK ON WOOD)

I'm in the same boat as you Mike though not as long. In 8 years I haven't had to replace a lens. I do have several spares however, they came with an Epilog Radius that was given to me - I ended up with several new and several barely used lenses of various lengths. Lots of mirrors too but I have to cut them down to fit - no hurry though, again, 8 years with the same mirrors. Clean them regularly with lens cleaner and lens cloth and it's amazing how long they will last!

[David Somers]

Good to know!!! Thanks everyone!!

Dave