30-50w laser diode

[work]

hi guys, i am trying to build my first laser cutter cnc machine, and i need some help... i hope the post is in the correct section and i will get a few answers...
i don't want to use co2 laser for my laser cutter... i really don't like them
now, i have the option to buy a used laser diode coherent... but i don't know nothing about it, hours of use etc. I know it may fail quickly, so ... i am willing to give it a shot just to see it working and cutting something....
basically i want to cut 1-5 mm soft materials like (cardboard, plexiglas, plywood, etc) maybe engrave some aluminium or steel
the diode power is 30 watts wave 877nm, and it works unde 2v and about 30amps... i know for sure if you apply 35amps it will provide 35watts (i won't risk that unless i have it and it's useless, just for fun)
the million dollar question is:
30 watt diode laser will equal with 30 watt co2 laser? what is the difference?
also i saw on youtube those diodes comes without any output optics... si i will have to focus the beam at the diode enclosure exit point, then drive it trough mirrors to the cutter head which will focus the beam more precise and prepare it for cuts.
is this correct?
there is a youtube video where it's used a 60w diode, and after a while of use the lens that focuses the beam explodes, i assume because of the heating? how can you avoid that?

any suggestion or information will be much appreciated.

thank you!

 

[diachi]

hi guys, i am trying to build my first laser cutter cnc machine, and i need some help... i hope the post is in the correct section and i will get a few answers...
i don't want to use co2 laser for my laser cutter... i really don't like them
now, i have the option to buy a used laser diode coherent... but i don't know nothing about it, hours of use etc. I know it may fail quickly, so ... i am willing to give it a shot just to see it working and cutting something....
basically i want to cut 1-5 mm soft materials like (cardboard, plexiglas, plywood, etc) maybe engrave some aluminium or steel
the diode power is 30 watts wave 877nm, and it works unde 2v and about 30amps... i know for sure if you apply 35amps it will provide 35watts (i won't risk that unless i have it and it's useless, just for fun)
the million dollar question is:
30 watt diode laser will equal with 30 watt co2 laser? what is the difference?
also i saw on youtube those diodes comes without any output optics... si i will have to focus the beam at the diode enclosure exit point, then drive it trough mirrors to the cutter head which will focus the beam more precise and prepare it for cuts.
is this correct?
there is a youtube video where it's used a 60w diode, and after a while of use the lens that focuses the beam explodes, i assume because of the heating? how can you avoid that?

any suggestion or information will be much appreciated.

thank you!

Can you post a picture of the diode or a link to the page where it is being sold?

 

[work]

here's a picture with the diode
thanks!

 

[crazyspaz]

877nm is significantly lower than the wavlength of CO2, so you should get better absorption by different materials. However you will need proper IR safety glasses or envlosure.

It will certainly need heatsinking, as well as a proper current limited power source.

Optics may be tricky....depends on what the laser is and if it's fiber couples or not. Do you have a link to the laser?

Oh also, one of our admins has a sale thread in BST section right now for a 40W 808nm diode. heres a link.
Co2 will be much easier to work with, both optic wise and power-wise. Finding a constant current 30A supply may be difficult.

 

[work]

Thank you very much for your replay again, i saw it after i replied first one.
I am aware i have to use safety glasses when handling such powerful lasers...
40w co2 laser tube cost in my country like 350$ + high voltage power supply 150$ + mirrors to drive the beam to cutting head... so i think it will const me over 600$....
such a diode is around 200$, and the one you pointed me is 250$ and it has the same power.
I have a low voltage/ high current power supply, and i`m also able to build one if this one is not enough (0-10v and approx 35amps) for driving the diode.
in this case the the cost is around 300$, and the diode can be mounted directly on the "z" axis so no mirroring involved.
cooling system is involved in both lasers cases, so it will be less then $50

using co2 laser is very simple, and everyone can build one
basically you buy all the parts and it should work....

using a diode laser it's not something you see every day, this is another reason i want to use it....

i also heard about fiber laser.... which it expensive, but much efficient, and higher power can be achieved (i've seen some demo on youtube and read a few articles) but in this case i don't understand at all...

thanks!

 

[diachi]

Thank you very much for your replay again, i saw it after i replied first one.
I am aware i have to use safety glasses when handling such powerful lasers...
40w co2 laser tube cost in my country like 350$ + high voltage power supply 150$ + mirrors to drive the beam to cutting head... so i think it will const me over 600$....
such a diode is around 200$, and the one you pointed me is 250$ and it has the same power.
I have a low voltage/ high current power supply, and i`m also able to build one if this one is not enough (0-10v and approx 35amps) for driving the diode.
in this case the the cost is around 300$, and the diode can be mounted directly on the "z" axis so no mirroring involved.
cooling system is involved in both lasers cases, so it will be less then $50

using co2 laser is very simple, and everyone can build one
basically you buy all the parts and it should work....

using a diode laser it's not something you see every day, this is another reason i want to use it....

i also heard about fiber laser.... which it expensive, but much efficient, and higher power can be achieved (i've seen some demo on youtube and read a few articles) but in this case i don't understand at all...

thanks!

It's a fiber coupled laser you have there, so that simplifies things greatly. Pretty much only need one lens to focus it to a spot. You could even attach a longer piece of fiber to the diode so that the diode can be mounted somewhere more convenient for heat management.

As for the driver - probably only need 0-3V at ~35A for that diode, although you'll probably want something with modulation (Either TTL or analog). Doesn't need to be fast modulation for cutting/engraving using an XYZ table, only if you are using Galvos does it need to be fast.

 

[work]

It's a fiber coupled laser you have there

wow, that's some news for me in this case!
So if i attach a fiber optic wire, i can route it on "z" axis, and place the diode somewhere convenient for cooling right?
so far it looks promising, BUT:

1. what fiber optic to use? i need the specs manual for this dioDe right?
2. how can i focus the beam to get the best result?
3. do i need a cutter head as co2 laser?
4. is it true that surface reflecting materials can't be cut with this type of laser?

thanks a million!

 

[diachi]

wow, that's some news for me in this case!
So if i attach a fiber optic wire, i can route it on "z" axis, and place the diode somewhere convenient for cooling right?
so far it looks promising, BUT:

1. what fiber optic to use? i need the specs manual for this dioDe right?
2. how can i focus the beam to get the best result?
3. do i need a cutter head as co2 laser?
4. is it true that surface reflecting materials can't be cut with this type of laser?

thanks a million!

1.) Depends on the fiber being used in the diode, it'll be multimode, not sure what size. Can you type up the P/N labeled on the diode and post it here? Can't read it well enough on the picture.

2) You'll want something like this for the end of your fiber:

It's a focusing lens that attaches onto the end of a fiber bundle either directly or with a connector. Can either collimate or focus to a spot. If you are using the CO2 cutter head (see below) you'll probably want to collimate to feed into the head.

3.) If by cutter head you mean the head with gas assist and focusing optics - then maybe. I'm not sure if laser cutters typically use gas assist at 30-50W CW - someone else that's used one might know. EDIT: Yes, you probably want one - even just to keep debris away from your optics by using gas assist. See if you can find a fiber laser cutting head - might get one on eBay. Might be able to use a CO2 cutter head in conjunction with a fiber collimator.

4.) If the surface reflects the wavelength you are using well then you'll have a hard time cutting it. For example, Q-switched Nd:YAG is better suited to metal than CO2. What are you trying to cut?

 

[work]

P/N 1070059
i will attach a closer image maybe some other info are useful.

2) You'll want something like this for the end of your fiber:

Yes, if i find one or if it's suitable for me

4.) If the surface reflects the wavelength you are using well then you'll have a hard time cutting it. For example, Q-switched Nd:YAG is better suited to metal than CO2. What are you trying to cut?

the first video from this playlist shows a laser burning metal without any difficulties, i know it's extremely powerful, but it doesn't seem to have any problems with reflections...
https://www.youtube.com/watch?v=ox0QcZ1KpNo&feature=youtu.be&list=PLu2F-Y0GjYJdn-MtbLWB7jG6F2fyV1sYq

i've found the video where it's used a 60w laser diode, and one of the magnifiers explodes...
https://www.youtube.com/watch?v=6QPbPrZX2cc


the second picture attached is what i head in mind when i said "cutting head"

 

[diachi]

P/N 1070059
i will attach a closer image maybe some other info are useful.


Yes, if i find one or if it's suitable for me


the first video from this playlist shows a laser burning metal without any difficulties, i know it's extremely powerful, but it doesn't seem to have any problems with reflections...
https://www.youtube.com/watch?v=ox0QcZ1KpNo&feature=youtu.be&list=PLu2F-Y0GjYJdn-MtbLWB7jG6F2fyV1sYq

i've found the video where it's used a 60w laser diode, and one of the magnifiers explodes...
https://www.youtube.com/watch?v=6QPbPrZX2cc


the second picture attached is what i head in mind when i said "cutting head"

The specs you posted in the initial post are incorrect.

Here are the correct specs as per the label:
Power:32W
Wavelength:812-816nm
Fiber: 800um Multimode
Connector: SMA 905

Thorlabs probably have what you need if you contact them. They stock fiber, and collimators. You can feed the output from a collimator into the cutting head.

You won't be doing metal cutting at 32W CW. The laser in the video you linked starts at 4,000W with the top model being 10,000W. At 32W you'll be able to engrave wood and non-transparent plastics. You should be able to cut thinner pieces of plywood, balsa and plastic etc.

If you keep your optics clean you shouldn't need to worry about them blowing up.

 

[work]

Thanks again for all the precious info's!
When i started to write the first post of this thread, i was looking to a different slightly higher laser, 45W but, and at the ending of the post i focused on the 32 watts diode.
I am not dreaming to cut 3cm of steel with 32watts but i saw that video and the laser hadn't any problems with reflection of the beam...
and if i remember well on the 40watt diode for sale by one of the admins, it says it cut aluminium foil without any problems...
mostly i want to cut thin plywood, balsa, plexiglas, copper foil (1mm), engrave some anodized aluminium, stuff like that. they are used in architectural models.
I think a co2 laser head as shown in previous picture it would be great if i can use because i can use an inert gas for preventing things to burn with open flame, and also helps with debris removal....

where did you find the last information about this 32w diode? like connector and what type of fiber optic to use?

thanks a million!

 

[diachi]

Thanks again for all the precious info's!
When i started to write the first post of this thread, i was looking to a different slightly higher laser, 45W but, and at the ending of the post i focused on the 32 watts diode.
I am not dreaming to cut 3cm of steel with 32watts but i saw that video and the laser hadn't any problems with reflection of the beam...
and if i remember well on the 40watt diode for sale by one of the admins, it says it cut aluminium foil without any problems...
mostly i want to cut thin plywood, balsa, plexiglas, copper foil (1mm), engrave some anodized aluminium, stuff like that. they are used in architectural models.
I think a co2 laser head as shown in previous picture it would be great if i can use because i can use an inert gas for preventing things to burn with open flame, and also helps with debris removal....

where did you find the last information about this 32w diode? like connector and what type of fiber optic to use?

thanks a million!

If you want to cut plexiglass you're going to want to go with CO2. Not sure how well copper foil will cut with 32W ~810nm, but I imagine you could do it. Perhaps you'd need to cover it in black ink first. Some experimentation will go a long way.

Yes - that cutting head should work with fiber anyway, you'd just need a collimator for the fiber.

Most of the information came from the Coherent website, or Google. Coherent has datasheets for these things - though I couldn't find that exact model number all of the FAP800 series use the same connector as far as I can see.

 

[work]

thanks again for all the help!
i ve sent am email today to coherent asking more information about this diode. hope to hear from them soon...
i think is am going to search for a higher power laser, i'm not rushing to buy this 32w diode. maybe i'll find a good deal in the next weeks.
btw what's the average "life" of a fiber optic laser like coherent ?

another thing that cross my mind right now is if i can combine multiple laser diodes (same power and model) will that increase the power?
let's say 4-5 32w coherent fiber lasers and collimate the beams in one, is it possible?

 

[diachi]

thanks again for all the help!
i ve sent am email today to coherent asking more information about this diode. hope to hear from them soon...
i think is am going to search for a higher power laser, i'm not rushing to buy this 32w diode. maybe i'll find a good deal in the next weeks.
btw what's the average "life" of a fiber optic laser like coherent ?

another thing that cross my mind right now is if i can combine multiple laser diodes (same power and model) will that increase the power?
let's say 4-5 32w coherent fiber lasers and collimate the beams in one, is it possible?

Don't know about these diodes specifically but typical ratings are >10,000 hours when run at specified currents for most diodes I've seen.

You could combine them, but it'd be easier to buy a more powerful diode or a big DPSS system, preferably with a Q-switch. You'd have better results that way too.

 

[work]

Hm... i'm waiting for the Coherent rely, i think i will need a more powerful diode... or use the co2 laser...
What is the smallest focus you can obtain with the laser diode, on co2 laser it's 0.03 mm

Thanks again !

 

[diachi]

Hm... i'm waiting for the Coherent rely, i think i will need a more powerful diode... or use the co2 laser...
What is the smallest focus you can obtain with the laser diode, on co2 laser it's 0.03 mm

Thanks again !

You'd be able to get a bit of a smaller spot, but in the end it depends on what optics you go with. A long focal length lens will give you a bigger spot and a shorter one will give you a smaller spot basically - there are other parameters that affect it, but basically. You'll probably get a little smaller than CO2, but you're talking maybe 0.01mm or 0.02mm instead of 0.03mm.