FAP 800 - Fiber Array Package

[Junkers]

This post is intended as a short preamble for anyone looking to gauge the suitability of the FAP800 series for metal 3D printing. If you have experiences you would like to share, post away!

With these units being as cheap as they are on the second hand market, they're tempting proposition for DIY metal 3D printing. Operating in the NIR, typically at around 800nm, they also have favourable characteristics for sintering Aluminium. The ability to manipulate a fiber, the lower moving mass, and ability to bring the focusing lens close to the powder bed helps achieve a tighter focal point too. There are some drawbacks to consider with these systems however. Their power requirements are unconventional, typically requiring 50A or more at 2.2V. Their sensitivity to reverse currents makes them susceptible to static or transients from fast switching. A low maximum operating temperature (30 - 40C) also calls for attention to cooling, typically utilizing Peltier/TEC pads and a sizable heatsink. That said, these challenges can be navigated with some diligence.



At this point in time, around $450 - 600 USD can cover the costs of setting up the basis of a fiber laser system. Fundamentally these systems are comprised of a fiber laser module (typically 40 - 50W), fiber patch cable, power supply, and focusing lens. The break down of cost is roughly:

- Fiber module: 120-200 USD (typically 40 - 50W)

- Fiber patch cable: 120 - 150 USD (SMA905 NIR 800um ~ Capable of 50W)

https://hsinjue.en.alibaba.com/?spm=a275...76e9yfRoEq - Specs: "SIH800 SMA905-SMA905 NA0.22 6.0mm wavelength400-2200nm 1M" - $125 USD delivered is what I paid. You will have to negotiate yourself.

- Focusing lens assembly: $40 - 70 USD (Coated for NIR)

- Power supply: 100 - 200 USD (SMPS vs Linear)

- Heatsink + Cooling fan/s + TECs: $40 - 100 USD

- OD 6 Safety glasses (Goggles preferably): $90 - $330 USD (Depending on brand - try to avoid unknown manufacturers)

(At the time of writing this, these are $89 USD + shipping etc https://www.laserglow.com/product/AGF-La...ty-Goggles)

[GoogleIt]

It's pretty cool that these sorts of laser modules are so cheap (relatively speaking).
Now for PSU what did you use? Would a server PSU work after doing some modding or adding a cheap Buck converter behind it?
A lot of filtering would probably be required I suppose?

[Junkers]

This is the unit I used:

https://www.aliexpress.com/item/32890998...web201603_

It worked fine for me but one thing I will mention is that it is not constant current i.e. you change the voltage, the current changes with it. It produces about 200mV of ripple which isn't great but my unit seemed fine with it. I've heard people insist on using Linear supplies but personally think they are being a bit anal-retentive.  At the other end of the spectrum, a channel on YT called "Endurance Lasers" used these:

https://www.aliexpress.com/item/32851821...web201603_

It's a bit of a rough solution in my opinion as you'll need at least 3 of them making current control a challenge. I've also found that their 20A output is overstated.

[GoogleIt]

Would it also be able to be used as a source for a "normal" SLS 3D printer? Or is the wavelength not good for that kind of purpose?
Didn't know these kinds of modules existed (certainly not for this price).

Happy I found this forum, has a ton of great knowledge already!

[Junkers]

Potentially. It really comes down to what you want to sinter with it. Being close to 1064nm (industry standard) I would think you're in with a good chance.