Vytek L-star series banding and lasering problems

[Jack Harper]

How long have you had your vytek laser for now? Are you operating it in a very "sterile" dust free environment? Yes, they warned us about the delicacy of the lens. It has not been cleaned on regular routine basis. I dont think it was our cleaning that wore off the coating, and vytek didn't accuse us of that either after they examined the photos i sent them of the lens.

I have had mine for about 21 months. We have it located in a 12000 sq ft space. The space is kept reasonably clean but given such a large space it does get dusty. I have added additional filters to the electronics and laser tube cooling as well as created air dams on each of the three mirrors to prevent dust and/or debris from getting to the mirrors. I have also increased the air flow to the lens to create a stronger dam from flying debris. As for checking the power, you can rent a power meter from laserbits.

[Bill Cunningham]

When your lens gets dirty with dust whatever, it heats up, and this is probably why the coating has failed. It may also explain the variation in the raster (not taking into consideration the obvious problems with the lens coating) as the lens gets hotter, it probably expands a bit, and with all the deflection on the bad surface coating as the lens gets hotter, the raster gets worse.. The lens looks shot, I can't see it ever working right again.. Just a thought...

[Rodne Gold]

IMHO That coating has been worn off by cleaning , time to replace the optic. Even the slightest amt of stone dust on the lens , combined with lens fluid will create a very nice grinding paste.
There is a VERY specific way to clean lenses and mirrors , for mirrors you lay a piece of lens tissue on it , drop a drop or 2 of cleaning fluid (kodak lens cleaner) on the tissue and drag it over the mirror , NEVER scrub.
With lenses , buy PECPADS (lint free cloth squares) at any photo shop , soak the optic in lens cleaner and shake it around to dislodge ANY dirt and then pat dry with a fresh pec pad. DO NOT SCRUB.....
I do however think you might have 2 problems , motion system slop + a bad optic. Banding is not normally associated with a bad final optic , that would give you consistently even poor results and not "band"

[Sandra Force]

What type of cooling system is used on your Vytek? I have found that if the cooling system is not doing a good job the "fire" from the laser will degrade. A down and dirty way to check this is to stop soon after it startes to loose power and feel the tube leading to the first mirror and see if it is hot. Warm is OK, hot is not. I think that Vytek is like mine and the laser tube travels on a gantry over the substrate, if so this will at least allow you to rule out overheating on the tube.

Also, check with Vytek and see exactly how many and where the mirrors are so that you can make sure that all of them are clean.

[victor belfour]

thanks for the information. We operate our laser in a large workshop but that opens into a sandblasting area. We try to keep it very clean but dust buildup is an ongoing battle. We undertook a thorough cleaning and blowing out of the machine and all panels and there was quite the cloud of dust around everything; so i think that helped but we're still getting issues.

By filtering do you mean additional intake fans in the housing on the side? there must have been a lot of work and machining to accomplish that. Do you void your warranty with vytek if you alter the machine like that?

If you have photos of your alterations i would be very interested to see how you implemented these modifications so that we could possibly do the same in our shop. I think we will have to do additional steps to fight dust in our environment.

Thanks for the input.

I have had mine for about 21 months. We have it located in a 12000 sq ft space. The space is kept reasonably clean but given such a large space it does get dusty. I have added additional filters to the electronics and laser tube cooling as well as created air dams on each of the three mirrors to prevent dust and/or debris from getting to the mirrors. I have also increased the air flow to the lens to create a stronger dam from flying debris. As for checking the power, you can rent a power meter from laserbits.

[victor belfour]

When your lens gets dirty with dust whatever, it heats up, and this is probably why the coating has failed. It may also explain the variation in the raster (not taking into consideration the obvious problems with the lens coating) as the lens gets hotter, it probably expands a bit, and with all the deflection on the bad surface coating as the lens gets hotter, the raster gets worse.. The lens looks shot, I can't see it ever working right again.. Just a thought...

thats seems pretty viable. We've undertaken a thorough cleaning and blowing out of the machine but are still having issues with dimming of etched images lasered on one side of the machine, but this dimming does not show up on images lasered on the the other side :P

Thanks for the explanation of the lens. Yes i think something like what you described has occurred and we have a new one on order. But i still feel there are other issues at work as sometimes the laser has been lasering pristinely and other times it doesn't and we're not sure why.

[victor belfour]

Thanks for the suggestions. We do have a new lens on the way. I do not think it was caused by excessive cleaning, but i have only been working here for 3 months and this is the second time we've cleaned the lens.

Thanks for the detailed instructions. I will go out and purchase some better cleaning pads as you suggested. I definitely wont use those ragged qtips that vytek supplied us with :P

Vytek did train some people here in their correct method of cleaning the lens which was to place it on a lens pad, place a drop of their supplied cleaning solution onto the glass lens and lightly draw another piece of tissue paper they supplied over the lens till it was evenly coated. No excessive rubbing was ever used. This hasn't been done too often i would suspect.

IMHO That coating has been worn off by cleaning , time to replace the optic. Even the slightest amt of stone dust on the lens , combined with lens fluid will create a very nice grinding paste.
There is a VERY specific way to clean lenses and mirrors , for mirrors you lay a piece of lens tissue on it , drop a drop or 2 of cleaning fluid (kodak lens cleaner) on the tissue and drag it over the mirror , NEVER scrub.
With lenses , buy PECPADS (lint free cloth squares) at any photo shop , soak the optic in lens cleaner and shake it around to dislodge ANY dirt and then pat dry with a fresh pec pad. DO NOT SCRUB.....
I do however think you might have 2 problems , motion system slop + a bad optic. Banding is not normally associated with a bad final optic , that would give you consistently even poor results and not "band"

[victor belfour]

thanks for the input.

I'm not sure what you mean by cooling? Are you referring to the air compressor that is shooting air down the shaft where etching occurs or on the laser housing itself? Whatever cooling we have now is whatevery vytek installed and after opening and cleaning the interior of the laser housing, it looks like there is only a single exhaust fan on the back of the laser as pictured here: laser cooling1 and here: laser cooling2

we shall try doing an aligning of the mirrors to see if that helps the problem. I'm not sure which tubing you're referring to or others have mentioned "laser tube" and i can't readily identify what that is as most of the laser assembly is housed in a self contained box and i dont think we want to open up anything more than what i've shown above.

What type of cooling system is used on your Vytek? I have found that if the cooling system is not doing a good job the "fire" from the laser will degrade. A down and dirty way to check this is to stop soon after it startes to loose power and feel the tube leading to the first mirror and see if it is hot. Warm is OK, hot is not. I think that Vytek is like mine and the laser tube travels on a gantry over the substrate, if so this will at least allow you to rule out overheating on the tube.

Also, check with Vytek and see exactly how many and where the mirrors are so that you can make sure that all of them are clean.

[Dan Starr]

Victor,
I also have an L-star 4896. From looking at the picture of your lens, I would definately think that is part of your problem. Mine was having similar problems about a month ago and after beating my head against the wall for a week (talking to tech support), I discovered that my mirror just above the lens was peeling like cheap chrome. Of course vytek was more than happy to sell me a new one for the bargain price of $200. So whatever you do don't order your lens from vytek, they will rape you. PM me and I'll send you the name of the company they buy their optics from, that should save you a few bucks.

[victor belfour]

Just wanted to thank everyone for their input into our situation.

My 1st new concern is does anyone else have a bit of movement or "play" in their laser tube assembly? What i'm talking about is the telescoping tube that emits the laser straight down onto whatever material that is being etched as pictured here: tube1
Since i've only been here a short time, i've come to notice a bit of back and forth motion (about 1 or 2mm) in the head when adjusting the optimal height for etching different thicknesses of rock. Could this account for varying degrees of banding or dimming of our etchings? If so do you guys perform any routine tightening of this mechanism? if so where? Here are some shots i've taken of the laser/emitter housing and the screws that hold it to the belt.
housing1, housing2, housing3

could any of the bolts indicated above need tightening? if so which bolts? the ones in RED or the one in YELLOW as indicated here: housing4?

The reason I ask is that in addition to the occasional banding and dimming of etchings, i also notice some "slurring" of the dots that the laser puts down as depicted here: blurring1, blurring2, blurring3.

A cross design that we've lasered many times before now comes out slightly "warped" in the horizontal area as shown here. This has led me to ask the question about the how much play there should be in the laser emitter.

My 2nd big concern: can someone identify this device: unknown1, unknown2? After staring at the housing around the laser emitter head for some time, i noticed this item was lose and moved it around assuming it was meant to be like that, closer inspection revealed it had been snapped off as shown in the 2nd photo, perhaps during a previous cleaning. I do not know how long ago this happened but it didn't look like it happened recently. we have no idea what is it, my assumption is that it is some sensor that is used to tell the laser that is has reached it's extreme top left position when you datum the machine. Am i correct? Should we glue it back down? it is resting comfortably in the place it should be.

[victor belfour]

We've run some etchings in various positions along the assembly where our laser etches and we are getting some varying results. Banding doesn't seem to be as prevalent after some serious cleaning (but we haven't run a large job yet).

We're still getting inconsistent results with our images, with some turning out less bright, less detail and having more contrast that other images.

For instance, a headstone we were etching the same design in the upper left and upper right corners as seen here turned out differently.

The Humming bird and flower design was first lasered in the upper left corner of the rock (as indicated by "image1" in the above photo). This image turned out dark , not much detail in the black areas and had to be lasered over 2x more to produce adequate results, even then it did not match the quality of our test burns on glass. See here: bad1, bad2

The same design was then lasered in the upper right corner of the stone ("image2") and came out very well with nice details in dark areas, much better brightness and adequate tonality. See here: good1, good2
I know the photos cant show you everything but the second burn did do much better than the 1st.

The laser was properly warmed up before each burn and leveled. I cant understand why we're getting better etchings in some areas and not so good in others. This is very confusing and i dont have a clue. Perhaps the 1st image being burned had the laser emitter further away from where the laser shoots off the second last mirror on the opposite side of the machine
and could indicate our mirrors might need better alignment? But we have done test burns on glass on the same side as where image1 was etched , but much further back and have produced very good result.

I have a headache trying to figure this thing out.

[victor belfour]

Thanks for the info Dan

PM sent.

I just discovered that mirror the other day and it was pretty grimy. Our was not peeling though, I cant imagine why yours would be other than poor manufacturing or a defect. Our was pretty dirty and we did a good cleaning but our inconsistent etching results still remain. I think Vytek charged us $200 cad for a replacement lens. It should be here next week sometime.

Victor,
I also have an L-star 4896. From looking at the picture of your lens, I would definately think that is part of your problem. Mine was having similar problems about a month ago and after beating my head against the wall for a week (talking to tech support), I discovered that my mirror just above the lens was peeling like cheap chrome. Of course vytek was more than happy to sell me a new one for the bargain price of $200. So whatever you do don't order your lens from vytek, they will rape you. PM me and I'll send you the name of the company they buy their optics from, that should save you a few bucks.

[Dan Hintz]

I definitely wont use those ragged qtips that vytek supplied us with :P

That's what they gave you to clean your lenses with, Q-Tips?!!! For shame! That will scratch the living crap out of them... no wonder the lens is FUBAR'ed.

That loose component is an IR photosensor... when the carriage gets to the end of its travel, the beam between the two black ears is interrupted. It's there to let the machine know when you're in a specific spot (the end), so you need to get that back into place. Otherwise, a large file may try to shoot the carriage off of the track end.

[Jack Harper]

thanks for the information. We operate our laser in a large workshop but that opens into a sandblasting area. We try to keep it very clean but dust buildup is an ongoing battle. We undertook a thorough cleaning and blowing out of the machine and all panels and there was quite the cloud of dust around everything; so i think that helped but we're still getting issues.

By filtering do you mean additional intake fans in the housing on the side? there must have been a lot of work and machining to accomplish that. Do you void your warranty with vytek if you alter the machine like that?

If you have photos of your alterations i would be very interested to see how you implemented these modifications so that we could possibly do the same in our shop. I think we will have to do additional steps to fight dust in our environment.

Thanks for the input.

We did not add any cooling fans. Instead, we added a high capacity filter to the front of the main power cabinet and the carriage vent for the tube. All we did was make a new flange to adapt a round filter to the square hole of the current fan filter. We removed the junk filter supplied with the unit and used filters for a wet/dry vac. These filters are readily available at you local Lowes or HD.

As for the play in the lens head, no we do not have any play what so ever.

I know you said you are new to the company, however, you do need to make sure the unit is cleaned on a regular, strictly adhered to schedule. Electronics degregate rapidly with heat and dust acts like a blanket concentrating the heat on the electronics. Cleaning will help but substantial damage may have already occurred.

[Demers Sunny]

Hello,
Hi have a Vy-Tek laser system Model LS-4896 and we try to adjust the mirror alignment of our laser but we have a lot of trouble to adjust it. So some of you have a trick to adjust it faster then pass a day to adjust it?