Laser Etched Focusing Panel vs. Ground or Acid Etched

[Mike1234]

I spoke to Bill Moretz Photo today regarding the Chamonix 45N-1 he worked on for me (installed a Maxwell screen and timmed/shimmed to exact specs). I asked him his opinion regarding finely ground vs. acid etched focusing panels and he said the new laser etched ones are the best. He also said they're not very expensive.

I've never heard of laser etched focus panels and my searches picked up nothing. He's emailing the information to me tonight.

Anyone heard about these or is there any interested in this?

 

[Steve Smith]

Anyone heard about these or is there any interested in this?

I have not heard of this but at work, I do have a laser cutter which can etch so I think there will be some experimenting going on soon!

I would be interested in seeing the information you get if that is possible.


Steve.

 

[Mike1234]

Might be a new business for you, Steve.

 

[nick mulder]

I'll make you a bellows - you make me a 11x14" laser etched GG

deal ?

 

[Mike1234]

How about you, Nick, making me a replacement Toyo 810G bellows... and you, Steve, making me an 8x10 laser etched focus panel? I'll not charge either of you a single penny.

Hey, I just realized one could easily add a grid pattern and/or clear aerial focusing holes with little/no extra effort... or clear corners that don't need to be nipped!!

 

[lilmsmaggie]

I'm assuming you are discussing etching the ground glass panel. If not, then you can ignore the information below.

Thought this excerpt from Wikipedia might be of interest:

Stone and glass
"Stone and glass do not turn gaseous very easily. As expected, this makes them generally a better candidate for other means of engraving, most notably sandblasting or cutting using diamonds and water. But when a laser hits glass or stone, something else interesting happens: it fractures. Pores in the surface expose natural grains and crystalline "stubs" which, when heated very quickly, can separate a microscopic sized "chip" from the surface because the hot piece is expanding relative to its surroundings. So lasers are indeed used to engrave on glass, and if the power, speed and focus are just right, excellent results can be achieved. One should avoid large "fill" areas in glass engraving because the results across an expanse tend to be uneven; the glass ablation simply cannot be depended on for visual consistency, which may be a disadvantage or an advantage depending on the circumstances and the desired effect."

Also, if the glass has a high lead content, it will retain too much heat for quality laser etching.

 

[Mick Fagan]

I have a LASER engraving machine, I also have a couple of attachments for engraving onto glass bottles, jars and drinking tumblers.

From what I can work out the LASER doesn't actually engrave, it melts the glass surface in a reasonably controlled manner.

You may have to be careful about the actual content of the glass itself and also the amount of air trapped in the glass during manufacture. I have found that quite thin glass has a definite tendency to crack, which we have put down to trapped air expanding.

My engraver is equipped with an air assist facility, I find that switching over to Carbon Dioxide instead of pumped air, does seem to reduce cracking with thin glass.

Thin glass to me, is anything under 3mm, usually 2.2mm to 2.5mm.

I'm not sure if the glass could stand the heat from the whole surface being etched, whereas engraving lines either in a squared manner, or a design seems to be alright.

Any thoughts Steve?

One way to find out

Mick.

 

[Mick Fagan]

Hmmm, just read the reply before mine, yep been there done that with very expensive crystal glasses with a high lead content, they explode.

Well they crack first, usually a few minutes after coming off the machine, then all of a sudden one hears a crack and they shatter into an expensive pile of shardonay!

Mick.

 

[bdial]

Hmmm, just read the reply before mine, yep been there done that with very expensive crystal glasses with a high lead content, they explode.

Well they crack first, usually a few minutes after coming off the machine, then all of a sudden one hears a crack and they shatter into an expensive pile of shardonay!

Mick.

Sounds like it must be an impressive sight!

 

[Mike1234]

I haven't received an email from Bill Moretz yet but I think he's been having email server issues. I'll call him again tomorrow to get the contact info telephonically. In the meantime if one of you brave souls tries it please be careful.

 

[nick mulder]

How about you, Nick, making me a replacement Toyo 810G bellows... and you, Steve, making me an 8x10 laser etched focus panel? I'll not charge either of you a single penny.

Hey, I just realized one could easily add a grid pattern and/or clear aerial focusing holes with little/no extra effort... or clear corners that don't need to be nipped!!

I always like the breeze of air you get at the corners when pulling the focus in - without those corners I reckon you might end up with a bloated or sucked in bellows - perhaps put a reed or two in there and you'll end up with a kind of lungless-harmonica

 

[Jeremy]

I always like the breeze of air you get at the corners when pulling the focus in - without those corners I reckon you might end up with a bloated or sucked in bellows - perhaps put a reed or two in there and you'll end up with a kind of lungless-harmonica

Just pull open the spring back a little when moving the standards long distances. I'd rather see all of my picture.

 

[Steve Smith]

Any thoughts Steve?

Not yet

One way to find out

That's the method I'm planning!

We normally just cut polyester on our machine as we use it to cut prototype parts in the membrane switch and flexible circuit business. I have some thick glass blocks which are used to hold sheet material flat. If I accidently run the laser over them at high power, splinters of glass come flying off so I think this needs to be a low power operation.

I usually just cut lines but it does have a raster image option too. One of the interesting things I have done for a control panel is to etch text onto an anodised aluminium sheet. The laser removes the anodising but will not affect the aluminium.

I will probably do some initial trials with polyester and polycarbonate before experimenting with glass.


Steve.

 

[david_mizen]

I would have thought the break up of the glass after lazer work is due to thermal stress glass does not like localised heat i did some glass work classes a while ago and we were taught always to do a controlled cool down 12 to 24 hours or more in the case of large pieces to keep stress levels to a minimum and equal across the body of the piece unquel stress/cooling = broken glass

 

[Mike1234]

Okay... I spoke to Bill Moretz today. He confirmed these are laser etched GLASS but are only available on the new 4x5 Technika cameras. In his opinion these laser etched panels are better than the best acid etched variety... the best of the best. He said he'll try to find out who provides the glass.

 

[Steve Smith]

How about you, Nick, making me a replacement Toyo 810G bellows... and you, Steve, making me an 8x10 laser etched focus panel? I'll not charge either of you a single penny.

Sounds like a good deal..... for somebody!


Steve.

 

[AgX]

Is this laser thing really about glass, or a resin which has been moulded/embossed via a matrix that was laser structured?

 

[Mike1234]

Is this laser thing really about glass, or a resin which has been moulded/embossed via a matrix that was laser structured?

I don't know anything about them but Mr. Moretz was very clear and certain that the new Technika GLASS panels are LASER etched. If I don't hear from him by tomorrow night I'll call him Friday to ask if he found the supplier of these panels.

 

[Mick Fagan]

Steve, my LASER was tested late last year when we installed another new beam set (2 x 25 watt beams in a water jacket).

Ostensibly it is a 50 Watt unit, but that is the minimum they must produce, mine tested at 69 watts after the initial bedding in and usage for a couple of weeks, it's powerful.

I can tell you that glass on my machine requires around 7% of power at 90% speed, that may give you some idea.

AgX, that was my first thoughts regarding the glass, plastics of some description more than likely. However it appears it could be glass.

Mick.

 

[Steve Smith]

I can tell you that glass on my machine requires around 7% of power at 90% speed, that may give you some idea.

I am half way through cutting some parts (for work) at the moment. When I finish writing this I am going to experiment with some small areas on a piece of glass - starting low and working upwards. I will report back later!


Steve.