is this a compatible setup? (laser cutter, first build)

[pow3r]

sorry if this has been covered before, i've done some research but i can't see any threads that match what i'm doing.
i'm looking to put together a laser cutting head for my CNC which i already have running. It's just to cut paper/card (all colours) and maybe leather or cloth.
I originally had planned to build a setup from a diode, and an lm317, but since its my first laser i thought I should start with at least a ready-built driver.

I'm going to be powering it from a desktop PC PSU, so i'll have access to 3v, 5v, and 12v power, and was planning to solder a 5v wire onto this <2w adjustable 445nm driver
then connect that to this 1.6-2w 445nm diode, then put it in a TO18 host (and of course grab some laser goggles)
then if i'm right i'll need to use my multimeter to dial in the potentimeter to 1.7A.

I guess the only questions i have are is this a compatible setup? also the cnc has a pc togglable relay which is in use to turn on and off the spindle when it's drilling, i was going to use this relay to toggle the laser power on and off for cuts, but is this safe for the driver circuit or diode?

 

[Things]

I'd get something like this: 445nm/405nm laser diode driver w/potentiometer/TTL [OL-BLD-1W] - $18.99 : Zen Cart!, The Art of E-commerce

It has TTL input, which means you can just supply 5V on a separate wire to turn it on and off, instead of turning the driver on and off.

 

[pow3r]

oh cool, so the ttl just triggers an internal relay of sorts on the driver?
would i be better off running a different diode with that driver, because it seems like the current it can put out might not be up to the diodes requirment. or can you safely underdrive it and it'll still be up to light cutting duties?

 

[Things]

Yes, diodes are fine being underpowered, as long as you're above lasing threshold. On 445nm diodes, this is around 250mA, so not to worry. 1.2A should allow cutting paper and thin card, as well as engraving on wood, and maybe some very thin plastic cutting. Cloth I think should also be OK, though leather might be a bit of a stretch.

TTL stands for transistor-transistor logic. 0v is regarded as off, and 5V is regarded as on. So yes, basically like switching a relay built into the driver. When I used to control my laser from the parallel port, I found out which pin was the Z dir pin, and connected the + TTL line right to that, so when the Z axis was moving down (As in, going to cut), the laser would come on.

 

[pow3r]

'You must spread some Reputation around before giving it to Things again.'

cool, thanks for all the help, i'll confess, i did buy this before i did much (any) research, but a bit of reading changed my mind.
One high burning power (500mW) 808nm TO-5 9mm laser diode + Gift*

after reading about some of the problems with IR lasers, i don' think i'll use it until i get a bit more familiar.

 

[Things]

Yeah, that won't really do what you're after. The good thing about 445nm lasers and other low wavelengths (like 405) is they are absorbed by more materials than near-IR. That laser probably couldn't even cut white paper, whereas 1W+ of 445nm will.

IR diodes are not good for starting off, as they are invisible. You could be roasting your eyes and not see a thing.

 

[pow3r]

cool thanks heaps for all your help, i bought those, and a variable focus host that i'll drill through a cpu heatsinc and fan then goop into place with heatsync glue. will post results when i get it together