Lasers - general chat.

[tweakie]

Hi Guys,

Kirk said :-
?I see a lot of different wavelength lasers, from DVD blue to infrared.  What's recommended for cutting gasket paper, along with being able to make grey scale Celtic knots and general fooling around??

As we know, different wavelengths have different effects on different materials so it is impossible to say what is best for general purpose use but, from a safety aspect, my personal preference would be infrared although most use blue (ex-blue ray player).

Last year I cut some gaskets from the G320 stuff using my CO2 laser (http://www.cooperman.talktalk.net/files ... age974.jpg) and they came out well but some other gasket materials I have here would not laser cut at all (it all depends on the gasket material composition).

Dan said :-
?I could not find anything bad about flexmod p3 I think I might go with it will I need to add that other thing you suggested also will it work with arts controller with out many problems?

The FlexMod has both analogue and TTL inputs and works in either mode so yes it should work just fine with Art?s controller.

?And what would be a good set up for a test driver/load I am a complete newbie when it comes to electronics?

I am not sure what others do but I used 3 of the high power Luxeon LED?s all connected in parallel with a multi-meter (set to Amps) connected in line with the bank of LED?s.
Just be conservative with setting the current ? we have probably all destroyed more than one laser diode by being too greedy.

Finally a word of warning ? safety goggles, with an OD rating at the wavelength of the laser being used, must be worn at all times the laser is in use or is capable of being brought into use. Children, bystanders, pets, etc must always be kept well clear of the work area and suitably protected from possible laser beam reflections.

Tweakie.

[DanL]

Thanks for that Tweakie yes glasses is a must I burnt my eyes with a reflection from my laser scanner, I wear the glass all the time even when the door is shut on it. and by god it hurt I still see spots when I close my eyes.

[tweakie]

Good example of the dangers associated with lasers Dan.

It is always best to learn from other?s mistakes rather than make the mistakes ourselves but I still remember getting ?Arc-Eye? as a kid from watching bro. doing some electric welding ? I was warned what might happen, took no notice and suffered the consequences for a couple of days. No surprise, it has never happen since.  ;)

Just a note regarding a theoretical worst case scenario when not using the appropriate eye protection...

Stray reflections from an Infrared laser can cause burns / tiny blisters on the surface of the Cornea. A very painful experience and a bit like Arc-Eye but it is, for the most part, self healing. On the other hand, stray reflections from a visible laser can pass through the Cornea and are then focused by the Lens onto the Retina where any damage produced will almost certainly be permanent.

Sorry to waffle on so much about safety but it is paramount.

Tweakie.

[DanL]

say that about ir laser Tweakie would it be better to get an ir laser for the reason that it a little bit safer.

it`s probable it wont be a problem for me using 445 laser as I am going to make a cover for the laser anyway in case one of my kids comes in to my shed.

I will draw up what I am going to make this and post it

[Mooselake]

Thanks, Tweakie!

I was leaning towards around a 2W IR laser, but I'll probably keep talking about one rather than getting it for a while - too many projects in the works until the snow gets too deep to work on the outside ones.  It'd be a nice addition to my QUBD RPM, if/when I get the missing parts to complete it, since it already has side panels.

Kirk

[DanL]

guys what would be better a 445nm 1400mw laser or a 808nm 2000mw laser as I can get both for the same prices they both have TTL controllers with them and I have seen the 445nm working if a 808nm would be better than a 445 I would get one with what Tweakie said about them it sounds a safer laser to use sort off

[tweakie]

guys what would be better a 445nm 1400mw laser or a 808nm 2000mw laser as I can get both for the same prices they both have TTL controllers with them and I have seen the 445nm working if a 808nm would be better than a 445 I would get one with what Tweakie said about them it sounds a safer laser to use sort off

Hi Dan,

I have absolutely no idea and I think that only you can decide which will be best for your application.

These are not mine just recent work by others as an example?

Analogue laser engraving using 455nm on birch ply by Jeff  http://kiskz.ucoz.hu/_fr/2/0424911.jpg
TTL laser engraving using 808nm on glass mirror by Dave http://kiskz.ucoz.hu/_fr/2/7431100.jpg

Tweakie.

[DanL]

thanks Tweakie

[Mooselake]

I have absolutely no idea and I think that only you can decide which will be best for your application.

If your application is general screwing around^^^^^^^^^^^^^^^^^^^^^^^self education then IR is somewhat safer and a better first attempt?  Most of my gasket paper is dark colored so either blue or IR has a good chance of working - or the auto parts store will have something else that might.

Kirk

[DanL]

art how do I add images to a post

[BobL]

DanL;

When you hit reply, click on " additional information" bottom left.. There you may add images..

Cheers
Bob

[DanL]

Thanks bob

This is how I think I will make the head and heat sink for my laser

[Mooselake]

After hemming and hawing (or perhaps we could call it deep introspective thinking and reviewing...) I just ordered one of those (claimed) 40W Chinese K40 Lasers from eBay, for not a lot more than the 2W solid state diode version I'd been looking at earlier.  It's supposed to ship out of California, so maybe in a week or so I'll see just how good a decision that was.

Kirk

[DanL]

good luck with that at lest you know if the controller is bad there is a good replacement

[Mooselake]

Yes, many choices for replacement controllers, from laserized Marlin on an arduino to smoothieboards to Mach3/4, with a lot of stops in-between.  From comments in the K40 G+ group and elsewhere even the Moshidraw controller and software might be getting better and be good enough for a while.  Remains to be seen, until then it's a project in a blue box.

First it has to get here without a lot of glass fragments rattling in the box.

Kirk