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Laser for sintering of metal powder

Posted by Nathan_T 
Re: Laser for sintering of metal powder
October 04, 2019 06:45AM
Viktor, I also have question about focusing of laser . As I can see, you used self-made focal lens. What lens did you use?
Is it better to use system "laser diode - fiber - focal lens" (not to mount laser diode on bridge of CNC machine, mount only focal lens)?
Did you ever take laser diodes and they worked not at full power?
VDX
Re: Laser for sintering of metal powder
October 04, 2019 07:05AM
... different lenses - sometimes "random finds", sometimes special PMMA lenses designed for IR-laserdiodes, sometimes optics for NdYAG- or fiber-lasers ...

Fiber coupling helps to separate the cooling from moving ... but reduces the power for the "losses" at fiber entry and output.

"not at full power" - do you mean faulty diodes?


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

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Re: Laser for sintering of metal powder
October 08, 2019 10:24AM
Quote
VDX
"not at full power" - do you mean faulty diodes?

Yes, you understood me correctly.
VDX
Re: Laser for sintering of metal powder
October 08, 2019 02:08PM
... my high power diodes are mostly salvaged from broken "diode-pumped lasers" - while the main laser is "exploded" for overpowering or back-reflexion, the pumping diodes are mostly OK ... until now only then not easy usable (but could be modified/reused too), when the attached fiber was burnt too short ...


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 for sintering of metal powder
February 26, 2020 04:51AM
Sorry, Victor, but I never got around to buy that laser (M1F4S22-808.3-50C-SS2.1 - 50 watts of power).
I find another M1F2S22-976.2-130C-IS34.2 (wavelength 975,7 nm).
Is 3.1nm line width obtained when using a collimator with this laser diode? How do you think?
The power supply scheme is no different than what you provided. But I attached it to this post.
Does HRP-450-7.5 (voltage adjust range from 6.8V to 9V) power supply suit to this diode?
Is it possible to initially calculate voltage drop across the regulator?
Attachments:
open | download - M1F2S22-976.2-130C-IS34.2.pdf (59.3 KB)
open | download - Power supply scheme.pdf (43 KB)
VDX
Re: Laser for sintering of metal powder
February 26, 2020 05:04AM
... fokussing with a lens is less problematic, than with shorter wavelengths -- did this with glass lenses without any AR coating - AR coating for NIR (800 - 1100nm) would be optimal.

You need 6 Volts for the diode and 2-3 Volts for the regulating -- so 9V from the PS ist OK ...


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 for sintering of metal powder
March 02, 2020 10:40AM
This is strange, but I can't find lens with AR coating in sale. Using lenses is better because energy isn't lost (almost) compared to a collimator?
VDX
Re: Laser for sintering of metal powder
March 02, 2020 12:19PM
... a collimator is mostly built with 2 or 3 lenses - so without correct AR coating much more losses than a single lens.

For my first IR-diode with 9 Watts @975nm I found some small uncoated lenses in an old "optics" kit -- they worked pretty well cool 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]
VDX
Re: Laser for sintering of metal powder
March 02, 2020 12:23PM
... by the way -- where are you located? ... have a bunch PMMA lenses with 9.5mm focal distance, which I'm using for IR-diodes above 30 Watts output power.

Got them from imos-gubela -- but they sell only batches ... [www.imos-gubela.de]


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

Call for the project "garbage-free seas" - [reprap.org]
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