Laser wood burning pen

Laser wood burning pen, made of a High Power Laser diode and a mechanical pencil.

For this project you will need:
-High Power Fiber Coupled Laser Diode.
-Mechanical pencil.
-Some kind of heat sink and some thermic grease.
-2 AA or D batteries or some kind of "clean" power supply.
-Laser eye protection.


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Step 1: Few word on the diode

The laser source is a high power IR laser diode with 1W out put. it burns everything except metal. You can get one on ebay .
The diode should work on 2V with constant 1.7A current it emits 830nm +/- 15nm laser radiation
the radiation is mostly Infra red and can be seen with a digital camera. Use glasses that filter 750nm to 900nm radiation for your protection .

I run my diode with 2 AA batteries, but it is not safe or the diode so you should make a small and simple constant current power supply that you can see HERE .

PAY ATTENTION on these diodes the (+) is the case, the (-) is the upper pin ! if you connect the wrong polarity you will probably burn your diode.

To run the diode for long periods of time i attached a heat sink to it so it won't overheat .
i got the heat sink from an old TV .i put some thermic grease on the heat sink to help the heat conduction .
You can use any kind of heat sink as long as you can attach the diode to it.
in commercial use of that diode they use Thermoelectric Cooler Peltier and fans to cool it down and prolong the diodes life because a new diode cost a couple of hundreds dollars.
DGW5 years ago
Does this thing really work? I don't see any photos of burn lines on wood! A 15 watt soldering iron will burn wood if you hold it there for 10 seconds. I seriously doubt a 1 Watt laser diode will burn anything other than your wallet. Prove me wrong please!
junits15 DGW2 months ago

wattage is not a measure of heat, it's a measure of power

genesis357 DGW3 years ago
it does. there's a huge difference between 15 watts of electrical current converted to heat and passed through a soldering iron than a 1 watt laser. 150 miliwatts will pop a balloon.
but will it kill a fly? think a long range fly swat. would it work?
what fly???? a one watt laser would vaporize a fly, if you could hit it.
xanxor R1Ch02 years ago
BMaier xanxor2 years ago
there exists actually a device to do such things (to defend gainst malaria mosquitos)
t.rohner DGW2 years ago
Look at the grand prize of the epilog challenge.
It's called a Zing16. The probability is very high, that it has a 16 Watt laser source.
With a 16 W CO2 laser, you CUT! 6th of inch wood or acrylic with a reasonable speed. The important parameter is the focus.
Normally you want the cut as narrow as possible, by focusing you also concentrate the 16 Watts on a 100th or 1000th of a inch diameter.
The entry model we sold had only 12.5 Watt, it's just slower than a 25, 50 or 100W model. (and costs 3 times less...)

When you only want to mark wood, the speed is much higher as you scan the image area with 500-1000 DPI.

he said one watt! not one miliwatt!!! learn your metrics! thats about 1000X the power of a dinky laser pointer!!!!!! learn your lasers!
Hello, have you ever seen a 100 Watt light bulb? One watt is nothing ! Even if light bulbs are only 10% efficent that much light is nothing. Sunlight is about 1.4 kW/square meter. Prove to me that a 1 Watt laser will burn anything.
SuperJesus DGW5 years ago
Thats 1 watt dispersed across over a large area. this is light thats focused into a highly concentrated beam. like a...magnifying glass.... come on man, this is kindergarten stuff. Don't tell me your THAT dense...
More precisely, it's focused into a 2-3 mm beam (about 0,07-0,08 inches for those who were not lucky enough to learn the metric system at all :P). Which means that 1 watt of energy is dissipated in an area of about 1.52x pi =7 mm2 (square mm, about 0.01 sq. inches). Quite a small surface for that 1 watt of pure energy, isn't it?
Real important to remember our species has no blink mechanism for IR. The blindness it will cause will be quick and permanent. I just bought 4 x 1W IR laser diodes for a project. Care is so necessary, I don't know what word to use.

It goes without saying that at such power levels you should ALWAYS keep the laser WAY below eye level and also to wear some protective eyewear as even stray LASER beams (weakened by reflection/diffraction) can blind you/cause serious harm. And losing one's vision sucks BIG time.
Big Bwana DGW5 years ago
Ok a 1 watt laser will burn wood, and sunlight is actually just under 1 kW/sq meter, if you where to take a 1 sq meter magnifying glass and focused it into a spot the same size as a laser pointer you could burn more then just ants with it, It would burn holes in aluminum with out much effort ( beer cans can be cut with less ) it would also make this 1 watt laser look like a toy.... So to prove to you what 1 watt is capable of, take a small magnifying glass, about 1 inch by 1 inch so you have less then 10cm2 which will amount to less then 1 watt of solar energy.. And see if you can burn wood with it... Try to be nice to ants while your out there..........
Sort of off subject but if one had a lense like that what would be safe protective eyeware? Would welding glasses be enough? I have a fresnel lense from back in the day when some were used to place in front of a tv set to make the screen appear larger. I was thinking of making a solar furnace for melting aluminum with it but I'd like to keep my vision too.
If you're working with solar light, welding goggles would probably be fine. If working with laser light, they would do absolutely nothing. You need laser goggles, made specifically to block harmful wavelengths of light given off by lasers. Welding goggles only protect against the brightness of a weld point. Intensity and wavelength are very different.
I see. Thank you. Another question, if one were to connect a laser pointer to the viewing lense of a microscope would one end up with a concentrated beam powerful enough to burn through wood? Metal?
A very good question. I don't honestly know. I don't know that a microscope lens would focus the beam properly. Given that the higher the magnification goes on a standard microscope, the darker the image becomes (at least on my microscope), I would say no, that it would likely restrict the light from the laser too much. But if you have microscope lenses to experiment with, I say go for it and let us know! Just make sure to get a good pair of laser goggles first!




too many caps. thanks
keyboard fixed now
haha thank god
Those dollar store 8 1/2 x 11 magnifing sheets will burn holes in aluminum pop cans ... So a one meter one should be able to toast a toaster....
toast a toaster awesome (w00t it's fixed!!!!!!!!)
hmmmmm that relies on you being 1.) outside 2.) it being a clear day 3.) having the spare money to buy a square meter magnifying glass and 4.) spending the money on that?! Also as one of the other comments states, 1W of laser light isnt equivilant to 1W of normal light anyway. It seems pretty quick at what it does in the video, nice one.
Project D DGW3 years ago

There's two sources right there. Concentrated, focused light is much stronger th!n general light.
trooperrick DGW5 years ago
lasers are converged (i think thats the right word) into a thin line, so all that energy diverges at a really slow pace. About the sunlight. Thats per meter. Would you want even half of that converged into a half a centimeter? Ever see a magnifying glass?
I'd rather just stick to my dinky little green laser pointer. It took having one bad experience with very brief reflection (from a coarse, white surface, not even a mirror!) from an un focused 150mW blue ray laser to make me realize how dangerous lasers can be.
i agree with you. DGW doesn't have a clue what he is talkink about! i know the difference between a 1 watt lazer and a dinky 5 miliwatt laser. dvd burners only use about a 40miliwatt laser. a 1 watt laser can cost up to $1,000 even. i believe you.
they use ~200-250mw diodes in dvd burners
DVD players 3-6 mw red
DVD burners 100-300 mw red
BluRay players use 100-120 mw blue

Laser light is collimated, or concentrated. The spot you see in the movie includes scattered light from a much smaller spot. They will burn wood. You **ABSOLUTELY** need eye protection, as even a quick flash from a reflection would blind you. Permanently.
actually im pretty sure that dvd burners use ifrared light because its not just reading the disk like a dvd player it is actually writing in the plastic
im sorry after i posted that i "rethunk" myself and i remember learning from tearing apart the burners and readers that the dvd burners use red light and the dvd players, cd burners and players use infrared a side note the little red laser pointers u get from a dollar store or whatever are less than 1mw
You are right. I think I was thinking about dvd players, not dvd burners.
Musicman41 DGW4 years ago
Yes a light bulb is 100 watts and does not instantly burn you.  You fail to notice that all that wattage is spread around the entire room.  The point of the laser is to take one watt of energy and concentrate it into a very small area, causing it to burn.  The laser is 1/100 of the power, but it is also about 1/100000 the area.
Arano DGW4 years ago
think again... he has 1W on less than one mm²
compared to sunlight (if it's true what you said): 1.4kW/m² = 14W/dm² = 0.14W/cm² =0.0014W/mm²
so the laser is (on the same area) more than 1000 times as strong as the sun
pmac93 DGW5 years ago
you have NO idea what you are talking about. A 1 watt laser is very high power. Comparing lasers to light bulbs is like comparing blu ray discs with cassette tapes! do some research before you doubt how powerful lasers are...

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