my first laser , driver question for cutting

[linekernel]

ok , i am more and more thinking that i should try them both

i totally get the idea rhd is expressing , but i don t really have any idea of the minimal size of the 445 beam ,

for now the only thing is that i can t find 700mW 405 diode.

so i ll try the 445mn first , and buy a 405 as soon as i can find one

and then , i ll make my best to document it

anyhow , thank a lot to you guys , i think i have learn everything i needed to start with lasers , this forum is real good source of knowledge !

 

[Cyparagon]

Thought experiment: if burning was only about power density, and not power - and if the focal point was proportional to the emitter size: the violet's dot would be ~1/7th that of a 445 (1x2 and 1x15 respectively, I think). That would mean 2W of 445 would cut as well as 300mW of violet. In my experience, that isn't the case - there's something else at play.

 

[mark-in-dallas]

For 12X 405nm diodes, you can try DTR, Flamingpyro or scopeguy20.

Another benefit to going with a 405nm diode is that the frequency is absobed my a wider range of colors. The 750mW 12X I had would cut through white plastic, while my 1.5W 445nm would barely scortch it.

And please correct me if I'm wrong, but if he's going to use it stricly as a cutting tool, would it not be better to go with something like a 2W 1008nm or higher infrared diode?

 

[linekernel]

The 750mW 12X I had would cut through white plastic

@mark-in-dallas : thanks it is really a good thing to know about the 405nm , if i knew it i would have gone for 405nm first

would it not be better to go with something like a 2W 1008nm or higher infrared diode?

that is what i thought first but then everybody continue talking about blue diodes
what would be the price range for a 2W , i found 5W for 135Dollars
i should have gone for it first , not i already ordered for more than 150 dollars , (without the price of the glasses)

obviously i should have wait more
, i first have to see if all i ordered will arrive to france !

i hope this thread will help people for the future of DIY laser cutting !

 

[linekernel]

ok they also have 4W for 85 dollars

do i need glasses for IR lasers?
if yes what kind ? 1008nm ?
where can i find some?

 

[mark-in-dallas]

You definitely need glasses for IR lasers, even more so than with the visible ranges in my opinion, because you can't see the beam or dot, and could damage your eyes before you even realized it.

As to pricing, I really don't know, but I'm sure someone will be back along to advise.

 

[linekernel]

yes thank you mark-in-dallas
i am interested to know as the 405nm is quite well focus-able , how about IR ? is it as well a good wavelength for sharp focus?

as for your 405nm 750mW; what is the max thickness you could cut (and in what material)?

 

[mark-in-dallas]

It isn't so much the wavelength that makes a beam more focusable, its how the diode operates, single mode, dual mode, etc. I do not believe that 405's or 445's put out any IR, because they are not combining frequencies to achive their wavelength, like the 532nm.

As to max thickness for burninjg, I really only burned through CD jewel cases, and the white plastic was an Airwick Air freshener that I burned a hole through, just to see if it would, and it was probably only around 1-1.5mm thick.

 

[linekernel]

so there is some wavelength diodes that are usually dual mode and some other wavelength diode that are usually single mode, so if you don t know what wave length is usually single and what wavelength is usually dual ;
you need a long read on the datasheet to understand what you are buying

the example you gave about plastic cutting is a good way to give a physical scale to somebody that never used powerful laser (and it good to be able to compare with what we can see in video on the net)
thanks

as for my project , i have already ordered 445nm 1.5W laser diode and everything
i am thinking that first , before trying 4W IR , i should stay in the lower power diodes to familiarize myself with laser and their dangers

so next i guess i will be ordering 405nm 700mW , but in few month
i already received my driver (FLXMOD) (and i realised it wont do for 4W IR laser , i ll have to buy a more powerful driver as for the day i want to try IR)

thanks everybody
i ll keep posting about laser tests (speed thickness colors material for the 445 first)
and then comparison between 445 and 405 once i get one of each .

 

[linekernel]

But please try to grasp the concept: It's a constant-current driver. It will output the same current with a 0.01 ohm load as it will with a 3 ohm load.

with some info i got from a laser blog (seems that i can t post the name) i could understand that the driver adapt it voltage for the load .

so now to calculate what intensity i need to set my driver at , i need the voltage the diode will drive , if it drives 4.5 volts , then i ll need 222mA to get a 1000mW output

i would then need a 6 volt (minimum) power supply because of 1.5volt lost in the driver ?

where can i get all the information about the A140 ? to be sure about the voltage needed for the diode ?

BTW i am ordering a 12X S06J from DTR real soon , so i ll be able to compare cutting power .

 

[linekernel]

i just realized i might have made a mistake when i bought the "405-G-2 Glass Lens W/Focus Ring $45"
isn t it a collimating lens ?
i would more need converging lens , am i right ?
where should i buy one ?

 

[Cyparagon]

A collimating lens can be used as a focusing lens by simply moving it farther away from the diode.

Yes, 6V or more is needed for the flexmod with this diode. You will need 7.5V or more if driving a violet diode.

if it drives 4.5 volts , then i ll need 222mA to get a 1000mW output

1000mW INPUT, maybe. Laser diodes are not 100% efficient. You'll need more like 1A+

Your only mistake was paying $45 for a lens when a $10 lens would be fine.

 

[linekernel]

if it drives 4.5 volts , then i ll need 222mA to get a 1000mW output

yes , i ll check in my power supplies to see what i have for over 6volts and over 1A

the question here is more , what should i set my driver intensity output at ?
is 222mA the good setup?

as for the lens it is ok , now i can compare lenses as i am going to buy a 405nm and a simple glass, and also RHD wrote that the cutting capabilities were dependent also of the lens , as for DTR wrote i could reach 600-700mW with the 405nm with the G-2 lens

 

[linekernel]

hi
ok so after a few problems i have been able to start my laser , i haven t done so many test yet , but i did try thin cardboard cut ,
i now understand better about the physicals values of cutting with laser diodes

you have to go slowly with a 1W
and you need the best focus you can get

i am now thinking that i should not go for a 700mW 405nm diode , and more go for a 4W or 5W IR

i ll keep in touch about my next cutting test in around a month or a bit more

thank you all for all theses information that Taught me a lot


out of curiosity and preparing about IR , does anybody on LaserPointerForums sells 4W or 5W IR diodes , or i ll have to buy it from china (if i buy one)?

 

[HaloBlu]

Your drawing machine is pretty neat!

It isn't so much the wavelength that makes a beam more focusable, its how the diode operates, single mode, dual mode, etc.

so there is some wavelength diodes that are usually dual mode and some other wavelength diode that are usually single mode, so if you don t know what wave length is usually single and what wavelength is usually dual ;
you need a long read on the datasheet to understand what you are buying

It actually single mode or multi mode, there is no "dual" mode.
All high power diodes seem to be multi mode. If you could find a single mode one it would likely be prohibitively expensive. CD,DVD,Bluray require single mode so any diodes that come from or were meant for optical drives (780nm,650nm,405nm) will be single mode.

IR can be very dangerous. Only buy certified goggles. OEM laser eye protection I really would Not trust these Multi Wavelength ones for High power IR, they aren't certified & you have no real guaranty. Be sure you have a large bright green 'power on' light. Green since it can usually be seen through IR laser goggles.
Also high power IR diodes can emit a wide stripe that would require extra optics to correct. Uncorrected I believe it will give a focus point that cuts only thin material well. It may be a problem if you ever want to go beyond cloth and paper.

out of curiosity and preparing about IR , does anybody on LaserPointerForums sells 4W or 5W IR diodes , or i ll have to buy it from china (if i buy one)?

Make a thread in Buy, Sell, & Trade, someone might have them.

Its a My Little Pony!

 

[linekernel]

hi HaloBlu
thank you for theses info , as i have now (quickly) tested my first laser , i can see that multi mode laser is already precise enough for cutting (i don t know if it is because of the quality of my lens or if it is just always that precise)

i wont be ordering IR or the right IR glasses for a wile because i have to make a CNC wood milling and 3d printer first (so i will make a thread for IR diode later)
i ll still try my A140 in drawing machine setup turned as a laser cutting machine , but i have to design the heatsink-laser/driver-holder and have it built first (+ make some new code for having a discontinued line).

do you think theses glasses are still ok for protection for my A140 running at 1W ?, because i had i little head heck the day i ran my laser (but maybe it was just a bad day)

yes you are right , the drawing is "My Little Pony"
i made it for testing-ameliorating code (of the drawing machine) + a gift to a friend whom is a big fan of My Little Pony.

Cheers
and thank you !