OT Laser score

[Noitoen]

I found this 50W RF CO2 laser and power supply on some industrial engraving equipment dropped off for recycling. If it works, it's just in time as I plan to build a 1000x500mm laser cutter to replace my Chinese K40. If it works, I think it's a good score I already have all the other components lacking only these 2 pieces so I'm hoping they're good

[mattthemuppet]

wow, that is a serious laser! Hopefully macona will see this thread and jump in. Please post pics of the final set up

[Noitoen]

wow, that is a serious laser! Hopefully macona will see this thread and jump in. Please post pics of the final set up

It's actually 2 lasers in parallel. One thing strange is that the manufacturers page says its a 50W but a sticker on the laser says Max 150W. I have to make a special PWM controller board for it as it requires a 1 microsecond wide pulse at a 200 microsecond interval as a "tickle" signal to pre ionize the laser for a reliable fire. I will try to test it next week.

[boslab]

Cnc tattoo removal machines are bigger than I thought, joking btw, nice chunk for free
mark

[J Tiers]

Better get some laser PPE..... if you don't have it. (Sounds like you know your way around, though) just reflections of the beam at that power level can do serious damage to you.

[macona]

Its two lasers in series. They use fold mirrors at one end to extend the length of the cavity which is the main thing that determines output power. On the lasers I have they use a slab setup where there are mirrors that bounce it multiple times down the length of the cavity in a zig-zag. In the case of the little (60w) coherent one I have it bounces 3 times I believe. It makes for a much shorter resonator.

Synrad makes good lasers. Photovac can re-gas them. They are kind of particular on their PWM freq but its pretty easy to make a control with an Arduino or a simple function generator.

CO2 lasers are relatively safe compared to other lasers. They are at 10.6um and they will not penetrate the cornea so unless you get a beam directly to the eye its not terrible. You cant damage your retina. That being said even a generic pair of polycarbonate safety glasses will stop a CO2 beam 100%.

Laser stickers almost never show what the true power of a laser is. It is always more. They just use one sticker for a lots of different lasers.

[Noitoen]

From what I understand, these work in parallel. They combine the beams optically. Since the beams are linearly polarized, they use a polarization sensitive beam combiner to achieve 98% efficiency in combining the 2 beams. The output polarization is random and therefore superior for many cutting operations. The can but should't be used independently.

[Noitoen]

Went back to the remaining of the machine and found the driver board that looks simple enough. I can't find anything online but it just needs power supply and has an opto-insulated input. My guess is that it already generates the tickle signal and only needs a regular pwm input to regulate the output. Just have to connect the oscilloscope to check it.

[Noitoen]

Hooked up the control board to the oscilloscope to check for the tickle pulses and the were good so I decided to test the laser and compare with my other one at the same distance from the tube and a 3 second shot onto an acrylic plate. The 2 dots on the red arrow are from the 2006 Synrad (2x25W) and the other 2 are from my 10 year old Chinese K40 laser that's supposed to be 40W.

Looks like I was lucky and now I can start building my big 1000x500 mm laser cutter.