240 mW laser pointer for $189 - what do you think about it?

Just found this site: [www.nitroxlasers.com]

They offer 240 mW at 650 nm Sony DVD burner laser mounted in MinMaglite housing for $189. Is this for real? Would you recommend it? Buy it? Any other application for this 'dangerous toy'?

I am a mechanical newbie - so please tell me how do I use such a beast (focus it) for laser cutting?

Howie

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Airspace V - international hangar flying!
[www.airspace-v.com] for tools and toys

240mW is probably only good for party tricks or eye damage! I doubt it would even cut paper (I'm no expert). I have just received a 10W laser and running at 1.5w with a 0.3mm

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Ian
[www.bitsfrombytes.com]

Hi Howie,

... it's an extreme dangerous 'toy' which can melt and burn good absorbing plastic, but for normal use as sintering-laser or CNC-carving it has not enough power, so the application will be very slow and extreme limited in possible materials.

The only application i see for reprapping or LOM-fabbing is cutting contours in thin sheets of black plastic (or other good absorbing and easy melting materials).

I built a diode-laser-welding-system with a comercial pigtailed diode-laser for 300 Euros with an atached glass-fibre with 100 micron diameter and 8 Watt output-power at 975nm.

This is much better for cutting, carvin/engraving and sintering and not so much expensiver - but you have to build a good power-source too, so i'll calculate 200 Euros more ...

But all capable laser-systems are extreme dangerous in handling and can cause severe damages in the eyes and on the skin and produce hazardous and carzinogene fumes, so i didn't recomend this way for common use!

Viktor

I would say that whoever is making these not only has very few ethics, but is also making a tidy profit..

Hello all,

My name is Justin, and I am a co-founder of the company that Howie mentioned, www.NitroxLasers.com. I stumbled upon these forums while doing some marketing research for our site, and I would be more than happy to answer any questions that you guys have about our products.


As far as what some of you were saying, I definitely agree that the $189 price tag is just a little too high, and I have arranged with my partner to setup a coupon code, NXL1, that will give all new customers $25 off their first order, bringing the total for one of these burning laser pointers down to $164, Priority Mail Shipping included. In addition, we offer a very competitive affiliate program, in which you will receive $20 for each client that purchases from us, and they will receive a $35 discount on their order.

I hope that I have successfully answered all of your questions, and I look forward to doing business with you in the future.

If you need any additional information, feel free to contact me at sales _at_ nitroxlasers.com.


Regards,

Justin
NitroxLasers.com

*edit* I really thought that I should add, if you wish to play with these things, your most expensive purchase must be a pair of laser safety goggles in the appropriate wavelength for the laser - $192 - [www.edmundoptics.com] - and although nitroxlasers do say at the bottom of their maglite laser page that they offer protective eyewear, none is listed on the laser safety section of their online shop. In fact nothing currently appears in the laser safety section of their online shop.

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*further edit* Don't build or buy one of these things. I've just thought about it a bit further, what is the purpose of a high power laser in a maglite? It's not suitable for any real applications I can think of other than as a camoflaged weapon for blinding people, or a tool for committing arson at a distance. I have removed my link to the site telling you how to make one, but left the rest of the post alone so you can see the price difference.

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or do it yourself...

DVD Burner - around $25 new - [computers.listings.ebay.com]
AixiZ Laser Module (just being used for its housing) - $4.50 new - [mfgcn.com]
Mini Maglite - around $12 new - [search.ebay.com]

so if using all new parts, that's just over $40

See - [on second thoughts don't] - for the instructions on how to build these dangerous little toys...

I hold to my previously posted opinion on the company selling these things

p.s. also, I very much doubt that anyone seriously considering building a repRap is going to be particularly worried about the difficulty level of building a DIY maglite laser thingy, a bit more market research may be in order... just a thought.

Edited 3 time(s). Last edit at 02/26/2008 04:09PM by deadgenome.

189$ for this is a robbery its just a old cd writer laser + power you can make one yourself basically good for party tricks as mentioned earlier

I just built one of these for a lot less than $189. About $35 for everything. Here are some pictures.


Top: [repetae.net]

Bottom: [repetae.net]

Front: [repetae.net]

Beam: [repetae.net]

A few notes:

Just taking that last beam picture, where the laser was on for a few seconds at most. my right eyeball hurts and is seeing spots. That is from the backscatter alone off of non reflective surfaces (and of course, me being totally reckless in not taking the time to find my goggles, no permanent damage done though I hope). Accidentally hit a mirror and you can blind yourself instantly. If it looks like a laser pointer, people won't be properly scared of it, you want to build it yourself to make it look dangerous. or at least like something people should think twice about picking up and turning on.

If you want to burn stuff or a pretty show, buy a good green laser. our eyes are much more sensitive to green light so the beam seems brighter. If you want a relatively cheap and fun electronics project, build one of these. The problem with red light is our eyes saturate at some point, that beam can be 10 times brighter and hence more dangerous and it wouldn't _look_ that much brighter.

Take the extra time to build the current controlled driver with the 317 chip. Your diode will go dead otherwise, many of the 'pre-built' ones online just have a cheap resistor and that is it, it will be bright when you buy it, but it will probably last just long enough for the return policy to expire (if they have one).

I bought this pre-assembled diode + axys assembly rather than messing with the optics myself. They also sell bare diodes and full driver circuits. in any case, you will spend a lot less than $189.

[stonetek.org]

Hey guys, I just wanted to let you all know that Nitrox Lasers has reduced its prices on the 240mw burning laser (from $189 to $134.99), and has also expanded its selection to include burning BluRay pointers. In addition, they now offer constant current drivers, that limit current to a safe level for a longer duty cycle and lifespan, in almost all of their devices. Their new store is here: [nitroxlasers.com]

Edited 1 time(s). Last edit at 11/10/2008 09:22PM by NitroxLasers.

Okay. But have a look at [www.instructables.com]

Howie

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Airspace V - international hangar flying!
[www.airspace-v.com] for tools and toys

>>NitroxLasers

somehow i think this is not the right community for your marketing style....

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David

Please guys if you intend build one on your own.
Do yourself a favour and wear safety goggles!

I'm not kidding, I ripped apart six or seven old dvdburners to make just exactly such a "toy".
With the last ..as I tested the diode after removing it from it's original heatsink I gave it a test , the uncollimated beam hits my shiny scissors and right into my left eye.
I've had a blind spot for almost a week, fortunate enough no lasting damage was made (according to my doctor on the third visit that week);
but boys, that scared the crap out of me.
And because I don't have appropiate goggles, I won't try again

And please, never ever buy a highpower IR laser at ebay if you don't know exactly what you are doing, you cannot even see the light, your lid WILL NOT CLOSE looking into its beam. Your eye will be toast.

take care

'sid

... this is the main reason why i stopped experimenting with laser-LOM-fabbing with the 1Watt-diode-laser - after changing the daywork i didn't have a laser-google anymore

I am even anxious when using office laser pointers that are said to be safe. I remember a TV show in the early days of 'party-lasers' where the camera was hit by a green laser leaving a colored spot on the image.

Oh, and I just came across an inexpensive and finished device: [www.dealextreme.com]

Watched one of the viedos where a guy ignited a match and burned a whole into some black plastic... Very instructive as a demonstration.

Howie

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Airspace V - international hangar flying!
[www.airspace-v.com] for tools and toys

Color me skeptical about how much we'd want to see a proliferation of laser-cutting Darwins out there.

It seems that much of the value of these machines is so that they can be used by average people in a fairly simple environment.

The hazards of laser cutters just seem too great, and seeing all of these kids buying high-powered laser pointers to play with at night clubs just worries me. Even as an engineer I'm not interested in having a laser cutter at home.

It's cheap,but I am not certain about its quality,I just bought a 200mw green laser pointer at [www.laserto.com] although it's more expensive,but it really does work well!

... 200 mW ?!?

I have two green laserpointers class2, much brighter then normal red laserpointers, and they have <1mW !

With 200mW even the diffuse reflection on a table-surface can hurt the eye !!!

Be extreme carefully with this dangerous toy - the IR/red diodelaser scavaged from DVD-writers normaly used for 'fuming and burning' have 220 mW and our eye is even more sensitive in the green wavelength, than in red or IR ...

Viktor

@Viktor: Even though our eyes don't saturate as quickly in the green wavelength as they do in the red (why green laser pointers appear brighter), I was under the impression that both are equally damaging to the retina, despite one seeming brighter than the other.

That's one reason why red laser pointers seem more dangerous to me -- they are just as damaging, but because they don't seem as bright, we're less inclined to be properly "afraid" of them.

I'm not much of a biologist / laser engineer though, so I could be completely wrong about those assumptions.

Edited 2 time(s). Last edit at 11/13/2008 04:12PM by HanClinto.

Hi HanClinto,

... the difference is mainly the eye-closing reflex which isn't triggered by IR and slower by red than green light.

But when the power is more then some milliwatts, then even the reflection of the beam in an object can damage the retina - be it a red or green laser-beam.

Selling such powerfull laserpointers as gadgets and toys is a crime - imagine some kids (maybe yours?) "playing Star-Wars" on the street ...

Viktor

Well but for our need it's simply "stupid" to use green lasers, as they are only ir-lasered crystals with a powerloss of about 70-80%.
To receive a 200mW green Laserbeam (depending on the specific wavelength and crystal in use) you can guess to have a 900mW to 1 Watt IR laserdiode fireing the crystal.

It's much more efficient to just have the ir diode to burn whatever is to be burned.

I'm sorry, didn't we had that conversation earlier?

'sid

All of this talk of amateur use of high-power lasers just takes the health and safety guidelines of the RRRF ( [objects.reprap.org] ) to a whole new level.

I think having a laser cutter on one of these things could be okay for the whole rep(st)rap conversion, but I'm still not looking forward to widespread use of these things. It seems to push the limits of the health and safety guidelines for the foundation, as well as the intended audience of these machines.

yep, I knew this LaserTo three months ago, their's laser is pretty nive, their website is [www.laserto.com]

I know that people say that the high-power laser pointers are not powerful enough to use in laser-sintering, but I have been wondering about that. The powder used in powder-coating metals is fairly cheap and melts at about 200-250F. If these lasers can melt through electrical tape and ignite matches, shouldn't they be capable of transferring enough heat to a bed of black powder to melt it at the focus point of the beam?

... yes, they would ... but it's more interesting how fast you can draw a 'sintered' line.

For sintering plastic powder to form a homegenous solid you have to reduce the focus down to 0.05mm or even lower (i have a 1Watt diode-laser with 0,06mm focus and it's melting/sintering, but not really fast when drawing a line).

For this you need very good optics and some more experimenting with materials.

Now imagine you want to build an object out of 0.05mm thick lines with a speed-rate of estimated 3mm/s.

You'll receive objects with a really fine structure - but you need a moving accuracy better than 0.05mm and the normal mug will need some weeks continuous run until finished ...

Viktor

I took a thermal analysis class last semester and I am taking a finite element analysis class this semester. I have tried to do a few calculations and simulations to see what it would take to heat up aluminum. I am not interested in cutting aluminum, but I had the material properties readily available so I used those. Also keep in mind that I probably have just enough knowledge to be dangerous. So take anything I say with a grain of salt.

I do not have the exact numbers readily available, but what the simulations seemed to indicate was this.
A 5 milliwatt beam focused down to about .4mm and assuming 100% absorption could heat the surface of an aluminum plate under the beam to several thousand kelvin. This is just taking into account thermal conduction of the plate. Add in radiation effects (a T^4 term), you get limited to about 1300K. Add in convection effects of about 100W/m-K(A value pulled out of my textbook) you at best get a temperature increase of 30K above ambient. So the real limitation to heating up a material with a low power laser(<1W) seems to be convective effects more than anything.

One thought I had with respect to limiting convective effects is using something like a piece of glass just over the surface you are heating. Of course there could be some problems if you have to remove air because of smoke being generated.

Another possibility is to heat the material of interest to just below the point of melting/burning/sintering and use the laser to take it over to top to accomplish the desired goal. Maybe using a heat lamp.The heat lamp preheat might particularly applicable to powder coating paints since they are meant to be heating in this fashion.

> A 5 milliwatt beam focused down to about .4mm and
> assuming 100% absorption could heat the surface of
> an aluminum plate under the beam to several
> thousand kelvin. This is just taking into account
> thermal conduction of the plate. Add in radiation
> effects (a T^4 term), you get limited to about
> 1300K.

Wow! Could this mean I could solder copper plated PCB using a green or blue laser of some 50mW?

The copper is only .035mm strong and on an epoxy carrier which does not conduct heat very well. I have to heat it only by some 300K on an area of about 1mm^2. Well, there could be a problem that solder reflects visible light rather well meaning that the heat has to be stored in this small amount of copper.

I know, this is a bit off topic - but interesting anyway. To put it back on track: What about a soldering reprap? Ideas? Solutions?

>>assuming 100% absorption

Correct me if I'm wrong, but I'm thinking this is probably not a reasonable assumption. Aluminum isn't going to be absorbing light very effectively. You're right that convective cooling is most important at these temperatures though.

@Corwin- I agree that 100% is not realistic in the aluminum case. For all I know it may take the 250mW to get the 5mW absorption and then you have to add in all other dissipative effects.

When I originally started calculating I was expecting conduction effects to be the dominant factor in limiting an increase in temperature. So I picked aluminum, but it looks like convection is the big factor.

One experiment that could be done to put some real world data into the mix is to shine a laser on a small k-type thermocouple. Try it with bare thermocouple and then painted black to find out how much of a temperature increase is possible. Also try it with some method to limit convection effects.

... i built a hard-soldering system with a 4Watt-diodelaser focussed to 0.1mm for soldering/brazing gold-paste on gold-pads.

I used some eutectic gold-tin-alloy (80% gold, 20% tin) with 400°C melting point (only first time melting, then 800°C) and 30microns diameter of the nearly uniform spheres.

For rising the absorption i mixed with 1micron gold-dust and as solvent/flux i used dexpanthenol.

Worked good, but i had only pads with 300x150 microns area, 15 microns thicknes and a small droplet of the paste of maybe 100 microns diameter and 50 microns height.

With thicker pads and bigger droplets (what would be neccessry for reprap-solder) i had to rise the laser-power to 6Watts and sometimes it didn't melt anyway.

Cutting plastic was easy, so i tried with a 1Watt-diodelaser and 0.06mm focus, what's nearly the same energy-density - but this works only with extreme good absorbing materials and the slow fabbing-time mentioned in my previous post ...

Viktor

Just to see what will happen, I have ordered some 0201 NTC thermistors.
I have some spare lenses and a cheap 1mw laser pointer, so I machined up a
simple optical breadboard to hold everything fixed.

When I get the thermistors, I will set it up as a target as a target and try to get some measurements
of the temperature increase. I should also be able to put some black paint on as well to increase the absorption.

While I do not expect to see a large increase in temperature of the thermistor,hopefully there will be some response..

When I get some real data, I will start a new thread and post the results.