6x 445nm-diode head

[VDX]

Hi,

... can't await the first 10Watt@445nm-diodes, so started with a bundle-head with 6x 1.6W@445nm-diodes (39€ each), but would be the same setup for 6x 2W (around 120€).

It's planned for engraving and brazing ... and later this year for 3D-fabbing with a multi-material support

Viktor

[TechJunkie]

I dont know about brazing. Rick Trent built a 15W 445nm set up, and it had a hard time cutting a small spring.

[masterpj]

The beam specs of 445nm aren't very good for engraving.

Why not use an IR pump diode with corrective optics? They have an ensanely thin beam and 5W 808nm sells for 96$ with FAC lens.

[VDX]

... beside the 445nm-diodes I'm using fibercoupled IR-diodes with 9Watts or 25Watts @975nm too ... will add 1 to 6 of them to the 445nm's later ;-)

With the IR-diodes emitting through the fiber the best focus diameter (or cutting/engraving line width) in 20mm distance is around or above 0.1mm ... with the 445nm diodes the smallest focus diameter (= engraving line width) in 20mm distance is around 0.04mm!

With the bigger focal distance in the multi-diodes head I'll get single focus sizes of maybe 0.1mm with the 445nm-diodes and around 0.2mm with the fibercoupled IR-diodes ... combined/averaged maybe 0.3mm ...

So let's see, what's possible with adding the IR-diodes ;-)

... and for brazing - mixed some pastes with gold-tin-eutectics and gold-dust and brazed/melted small amounts of the paste on gold-pads with 4Watts IR ...

Viktor

[JJWMACHINECO]

The beam specs of 445nm aren't very good for engraving.

http://www.photonlexicon.com/forums/...-of-Grey-445nm

[VDX]

... engraving black anodized aluminium with a single diode at around 1.5Watts:

http://www.youtube.com/watch?v=ZTYuF...RqX9QR5LaCN7yw

[TechJunkie]

... and for brazing - mixed some pastes with gold-tin-eutectics and gold-dust and brazed/melted small amounts of the paste on gold-pads with 4Watts IR ...

Viktor

Sorry, when I hear brazing I think heavier metal. You're basically soldering, not brazing.

[VDX]

... AFAIK soldering is defined until 450 degC, (normal) brazing from 450 to 900 degC and 'high-temp'-brazing above 900 degC.

The used gold-tin-eutectics needs around 400 degC for the first time melting, above 600 for a second melting and around 800 degC when 'settled' or in combination with gold-dust. Here an image from the connections I've made with the gold-paste (the thicker wire was 10 microns diameter, the thinner one 1 micron, the pad around 0.1mm wide): http://www.reprap.org/wiki/File:Brazing.jpg

The possible temperatures with lasers are depending on the max. power and thermal conduction of the powder (or wire) and solid base - tested with tungsten-powder and t.-wires, 'brazing' them on solid tungsten with a 2kW-pulse-laser ;-)

Actually I have in my basement some IR-diodes with 5, 9 or 25Watts or combinations of them for higher powers ... and a fiber-laser with 50Watts @1070nm on a spot of 10 microns ...

Viktor

[TechJunkie]

Yeah I'm not really technical, I'm more hands on. I was a mechanic, and welder so thats all I can base my opinion on unfortunately.

[VDX]

... here a video where I've tested the 'refurbished' servo-CNC-mill with a single diode engraving wood with 30mm/s ... next week I'll start testing different materials, alternative methodes and higher speeds with single diodes and the 6x head ...

https://vimeo.com/87280864

Viktor