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Laser Cutting Head

Posted by aka47 
amk
Re: Laser Cutting Head
December 30, 2010 04:28PM
Hello VDX,

Its nice to see 1W of blue laser emission! Have you tried cutting through anything like thin plywood?
Are you planning to use the filters for a safety enclosure? Something I came across recently is a calculator to estimate the OD required for safety, it might be of interest to you: [www.laserinstitute.org]
Anyway, I guess you could do a crude test by placing the filter in front of the laser and see if it transmits any light!

all the best.
VDX
Re: Laser Cutting Head
December 30, 2010 04:42PM
... thanks for the link!

I have only 4 of the plates, so not enough for an enclosure, but enough for some goggles.

When testing with them i can't see any blue transmission, but i can see the spot in orange, so i'll estimate an absorption of maybe 98% of the blue light at 445nm and full transmission of the glowing, what's not so bad grinning smiley

This plates were samples of UV-shielding for photochemical PCB-generation, so 100%-blockers for UV and blue.

When pointing with the laser through the plate directly, it blocks the beam completelly and melts/burns away slowly, so the shielding effect is more absorption than diffuse reflection ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
amk
Re: Laser Cutting Head
December 31, 2010 10:28AM
Hi Viktor,

You could probably use them as windows in an enclosure.

Do you have any transmission/absorption/OD data from the manufacturer to be on the safe side? According to the link, for 1W @ 445 nm CW you need an Optical Density of 3 which corresponds to a transmission of just 0.1%. More than likely you'll be ok, but when its your eyes you have to be careful!

Absorption is good - if your (goggle-covered) eye is in the beam path you'll smell/see/hear the burning and get out of the way!

What focal length lenses do you use for the tests with balsa with blue and IR? If the laser divergences are the same (probably not I guess!) then the same lens will give a smaller focal spot for the blue (spotsize depends on wavelength).

Has anybody tried sls of ceramics? I'm thinking it could be a good insulator between the hotend and extruder body... but maybe somebody has already tried and ruled that out!

I'm building a repstrap with a uv laser marker (slowly!)... hoping to use it to build a mendel and try it as a laser cutter if I can redirect my marker beam or else maybe get some diodes... its early days yet smiling smiley
VDX
Re: Laser Cutting Head
January 01, 2011 05:16PM
... i use two small plastic lenses for the 445nm-diode which the seller added, maybe salvaged from the beam-shaping in the Casio-beamer?

I've fixed the blue diode to my CNC-mill and tested with black 0.3mm plastic:

Here with 1Watt and 500mm/min cutting speed:

... here with the UV-filterplate:

... tattoo ready:

... and cleared:

The focus is bad, maybe 0.15mm diameter compared to 0.1mm with the IR-diode.

When the collimator arrives, i'll test with other lenses - i hope to receive then a spot diameter of 0.05mm, so the energy density and cutting speed should increase dramatically cool smiley

Edited 1 time(s). Last edit at 01/01/2011 05:18PM by VDX.


Viktor
--------
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Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
January 01, 2011 06:01PM
VDX Wrote:
-------------------------------------------------------
> When the collimator arrives, i'll test with other
> lenses - i hope to receive then a spot diameter of
> 0.05mm, so the energy density and cutting speed
> should increase dramatically

0.05mm should be great for PCB black paint etching. And if you can cut 0.3mm plastic with that laser diode then I am almost sure it will be able to etch the black paint :-)

My experiences/ideas:

- 11€ 500mW IR 808nm diode laser bough on Ebay, testing it against a black plastic bag - there are no lenses: laser_500mw_808nm.ogv


---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

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VDX
Re: Laser Cutting Head
January 01, 2011 06:23PM
... my first IR-diode is a fibercoupled [email protected] type - see the first image in the wiki-page: [objects.reprap.org]

I tested with different materials and black plastic with maybe 500mW output power and the 'perfect' colimator-head visible in the image too.

The fiber has a core diameter of 0.05mm, what's 1:1 transferred to the focus diameter - but the 445nm diode seems to burn better than the 808nm diode! ... i think the absorption with 445nm is much better than with 808nm or 975nm, so a blue 445nm or BluRay 405nm diode will work much better with black paint on copper than IR-diodes ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
January 01, 2011 06:34PM
VDX Wrote:
-------------------------------------------------------
i think the absorption with 445nm is
> much better than with 808nm or 975nm, so a blue
> 445nm or BluRay 405nm diode will work much better
> with black paint on copper than IR-diodes ...

Ok, but I am seeing 808nm 500mW costs 11€ on Ebay while 445nm and 405nm are much more expensive, like 5x times more!

If a 11€ 808nm diode work for PCB etching, I would go for it because it's the cheaper.


---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
VDX
Re: Laser Cutting Head
January 02, 2011 03:20AM
... the [email protected] is good for this too - with 445nm you have better visability of the beam/spot, so you'll have better security-relations ... both, 445 and 405 have shorter wavelengths, so better focus ... and the shielding with UV-filters seems to be easier than with IR.

I've bought the [email protected] BluRay for 30 Euros and ordered yesterday two [email protected] for 35 Euros each - here i can occasionally order some more too ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
January 02, 2011 06:02AM
VDX Wrote:
-------------------------------------------------------
> ... the [email protected] is good for this too - with
> 445nm you have:

You wrote advantages:

- better visability of the beam/spot, so you'll have better security-relations (security is very important!!!!)
- shorter wavelengths, so better focus (important to etch very small lines/dots, higher resolution, more power when better focus)
- shielding with UV-filters seems to be easier than with IR (again, security)


> I've bought the [email protected] BluRay for 30 Euros
> and ordered yesterday two [email protected] for 35 Euros
> each - here i can occasionally order some more too

Please report if you get any "damage" or "fake" diode.

And, for [email protected], a 3 OD googles are needed: [www.laserinstitute.org]
Did you bought such ggogles? - I am not finding them on Ebay...

Even if we can buy the goggles, we need a way to test them because I do not trust in sellers...


---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
VDX
Re: Laser Cutting Head
January 02, 2011 01:49PM
... i have goggles for IR and will use the orange UV-shielding plates for the blue and UV diodes.

I tried with 445nm-blue what's nearly complete eliminating the blue emission and should be even better for the 405nm diode ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Laser Cutting Head
January 30, 2011 02:56PM
Update...

... finally i've got today some 9Watts- and 25Watts-IR-diodes and my AOM for the fiberlaser is fully functional, so i'm actually busy wiring some diode drivers with 10Amps and fixing the AOM-head with focussing head over my CNC-mill working area ... some images will follow, if it's working ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
February 14, 2011 05:51PM
I am talking/following Leonardo working on testing blue laser of 1W -- he found that his RepRap Mendel don't have the needed precision/mechanical quality for laser etch PCBs sad smiley

Now I need to go and test with my CNC, since my Reprap Mendel have just the same problems as the Leonardo RepRap Mendel.

Read here the blog message with the tests: [reonarudo.info]


---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
Re: Laser Cutting Head
February 14, 2011 06:27PM
Mendel aims for a resolution of 0.1mm and that is certainly not enough for fine pitch PCBs.


[www.hydraraptor.blogspot.com]
Re: Laser Cutting Head
February 14, 2011 06:29PM
nophead Wrote:
-------------------------------------------------------
> Mendel aims for a resolution of 0.1mm and that is
> certainly not enough for fine pitch PCBs.

Oh men, just now I saw that info on Mendel first page: [reprap.org]

I didn't know that. Seems that the laser cutting line are of 0.2mm...

Time to go for CNC and forget RepRap for this task.

Edited 1 time(s). Last edit at 02/14/2011 06:33PM by casainho.


---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
VDX
Re: Laser Cutting Head
February 15, 2011 03:11AM
... you can enhance the accuracy of a Mendel by stiffening the frame (e.g. with diagonal steel wires), using steel reinforced belts and metall pulleys.

But for accuracies below 0.025mm you need a even stiffer mechanic and spindles with ball-bushings instead of belts.

My CNC-mill is specified with 0.025mm with fullstep and 0.0125mm with halfstepping (so even more with microstepping), but i have mechanical issues when trying to go better than 0.01mm.

For this i'm building a new frame with three high precise linear stages with motors and drivers capable of 0.5 micron resolution ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Laser Cutting Head
April 07, 2011 03:01AM
... beside developing a conversion kit for generic CNC-mills (i'm converting an Isel mill) i modified one of my 5Amps-drivers to 8.6Amps max. current by replacing three of the LM317 by LM338 and changing the sense resistors - image here under "power source": [objects.reprap.org]

When the CNC-kit works, i'll apply a 9Watts- and a 25Watts-laserdiode (both needs 9Amps for max. power) and melt some powder winking smiley


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
June 27, 2011 08:17AM
Can't you just stick a Blu-Ray drive laser to a platform and use it like a laser? I would recommend making a reflector-sort-of-thing out of metal or non-see-through acrylic to stop the beams reaching you're eyes and making you blind
VDX
Re: Laser Cutting Head
June 27, 2011 01:39PM
... i have a [email protected] diode aimed for photochemistry, but [email protected]m (blue) or 5 to [email protected] (IR) is more interesting for applications like engraving, cutting or laser-sintering ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
October 12, 2011 10:18AM
Dear All,

Any ideas about a good CO2 laser cutting head to perforate PET bottles on a moving conveyor belt?
The PET bottles might be clear transparent or colored, wrapped with paper sometimes.

It is important not to produce flame or fire while cutting.

Your soonest feedback to marwan.habbal@leedsintl.com would be appreciated.

Thanks in advance!
Marwan
VDX
Re: Laser Cutting Head
October 12, 2011 10:53AM
... has it to be a laser or can a heated needle or a needle/projectile gun do the same?


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
December 03, 2011 08:40AM
halo everybody,

one of the problems of the 1watt 445nm units is that in reality they are a multidiode solution (2x500mw) and that affects the the size and shape of the beam (1watt 445nm beams are not round).

there is a debate about if a single diode 500mw 405nm diode will focus better (and have better cutting results) than a 1watt 445nm unit. But on the other hand 405nm is not visible so focusing can be a bitch smiling smiley

Im not sure for which solution I will go for, any insights?
Re: Laser Cutting Head
December 03, 2011 09:31AM
waste Wrote:
-------------------------------------------------------
> halo everybody,
>
> one of the problems of the 1watt 445nm units is
> that in reality they are a multidiode solution
> (2x500mw) and that affects the the size and shape
> of the beam (1watt 445nm beams are not round).
>
> there is a debate about if a single diode 500mw
> 405nm diode will focus better (and have better
> cutting results) than a 1watt 445nm unit. But on
> the other hand 405nm is not visible so focusing
> can be a bitch smiling smiley
>
> Im not sure for which solution I will go for, any
> insights?

I didn't invested more on the idea of laser diode on RepRap because I am afraid to be blind. If I would know it could work in a safe way, I may invest more. I will continue monitor this message.

Waste, do you have any experiences? any blog messages that I can read about your works?


---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]
Re: Laser Cutting Head
January 14, 2012 11:41AM
Hi,
I would like to convert a graphtec fc2200-90 flatbed cutter to work with a laser beam.
I would like to cut several layers of clear plastic of 500 microns to an overall depth of 5mm giving me 10 layers in total.
Can anyone suggest a simple conversion kit that would do this job.
Thank you
Linda
VDX
Re: Laser Cutting Head
January 14, 2012 04:32PM
Hi Linda,

... for clear plastic with 5mm depth you'll need a CO2-laser with some ten Watts of power - there's no 'simple conversion kit' out there ... search for "CO2 laser engraver" in ebay ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
February 19, 2012 06:02PM
Hi

What do I need to cut 3mm black acrylic?

Thanks
VDX
Re: Laser Cutting Head
February 19, 2012 06:13PM
... how fast?

Slow cutting with several passes is possible with 200mW or more with any IR- or UV-diode (as black absorbs any wavelength) ... for fast cutting you'll need some ten Watts ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
February 19, 2012 07:07PM
what do you think about this laser with this case for slow cutting?

would the orange acrylic be able to block the IR radiation?

thanks

Edited 1 time(s). Last edit at 02/19/2012 07:08PM by ricros.
VDX
Re: Laser Cutting Head
February 20, 2012 12:39PM
... the diode is OK ... [email protected] will be better (and better visible and shieldable too).

The case is good for maybe 0.5W continuous operation - for 1W and above you need a more solid block of aluminium and/or a TEC (ThermoElectricCooler e.g. a Peltier-element).

Orange acrylic isn't usefull with 808nm - it's only good for UV (works for 445nm too) and for the 10640nm of a CO2-laser (as any acrylic/organic or glass) ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Laser Cutting Head
March 05, 2012 05:08PM
... from another thread, but could be interesting here too - atached images of a typical 'laser-plotter' and the toolhead with integrated diode or only collimator and optics:





Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Laser Cutting Head
March 06, 2012 03:01AM
Thats a nice plotter Viktor,
Wish I had such nice toys, having said that, I have been given a 3watt argon laser, very old so may not have any gas.


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