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.

WARNING USE A PROPER EYE PROTECTION WHEN USING HIGH POWER LASER !!!
"NEVER LOOK DIRECTLY AT THE LASER BEAM ! LOOKING AT THE BEAM WILL BLIND YOU INSTANTLY !!!

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.

Comments

[extremeseeker]

where can you get a 1 watt laser diode anyway?

[Drpepperspray]

what does a heat sync do?

[facilitator476]

heat sinks cool off critical components in electronics. If you were to take off the side of your computer ( its usually held on by a latch or a couple of screws on the back) you would see long strips of metal sticking out from the motherboard where the CPU is, the heat sink takes heat from the CPU and it gets cooled off from fans. (nowadays most computers have fans built over the heat sink to cool high performance processors)

[DGW]

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!

[t.rohner]

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.

[Project D]

1W of laser energy is a LOT of power and can do significant damage to things. Just look at the Arctic 3 Spider from wickedlasers.com. There's a reason most laser pointers are only 5mW.

[genesis357]

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.

[R1Ch0]

but will it kill a fly? think a long range fly swat. would it work?

[genesis357]

what fly???? a one watt laser would vaporize a fly, if you could hit it.

[R1Ch0]

brilliant.

[xanxor]

^like

[wangtrevor]

... if it can burn cd's it can burn you

[knoxarama]

youtube has videos of pens just like this burning wood.

[sadunpererarules]

haha. dude , u just got cough cough---burned, by these guys. haha, they so mean

[revo101]

dude a 245mw hand held laser can burn wood. I dont know what white powder your sniffing but im sure other ppl thing ur on cocaine as well

[thinker]

there arent photos THERES A VIDEO its a concentrated high intensity beam soldering irons have general heat dissipated across a large surface and most of the energy is lost and the rest is not concentrated you can burn paper with a magnifying glass with radius 4cm (probably under, but i just measured my one and ive burnt paper with it before, so know it works)

[KEYBOARDISBROKEN]

2.5CM CAN BURN WOOD, ON A CLEAR DAY

[CoolKoon]

Concentrated sunrays can melt your pennies away as well. You have to use some big lens for that though....... I think I've seen an instructable about that too.

[trickster208]

OH!! Burn...

[Red Raider]

dude watch the youtube video he put on here it shows him drawing on the wood by burning it with the laser!

[monkeywithawrench]

he said one watt! not one miliwatt!!! learn your metrics! thats about 1000X the power of a dinky laser pointer!!!!!! learn your lasers!

[CoolKoon]

Hmmmmmmm......looks like learning metrics by Americans getting (or wanting to get) involved in science might even pay off as well......well, if not, you can still be nominated for the Darwin prize :P

[DGW]

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.

[Project D]

WickedLasers.com

YouTube.com

There's two sources right there. Concentrated, focused light is much stronger th!n general light.

[Musicman41]

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]

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

[insomartin]

with a 2 cm diameter magnifying glass, you could burn paper and kill ants. you do the math.

[CoolKoon]

Well, watch the video. He's "carving" the wood with that laser beam (he must've used a dig. camera, as light in the 800 nm range is quite invisible to the human eye, and the drawing is pretty precise).
Or if you want to put it this way, this specific laser dissipates an energy of about 0,14 W/mm² (which is about 14 kW/m²).
Still don't believe me? Then do the math yourself OR try this stuff on your own hands.......(DISCLAIMER: I do NOT recommend pointing ANY kind of LASERs to ANY body parts, so I may NOT bear ANY responsibility for someone being stupid enough to do it, especially with a 1W laser)

[webbie]

To answer your question, you need to understand why LASER is called LASER, once you get the answer of this question you will know how LASER is different from ordinary light and why 1W of laser beam is much more (effectively) powerful than 100W flash light.

Lets start with basics..
LASER = Light Amplification by Stimulated Emission of Radiation.

Thats a big word, isn't it?

Now to understand light, you have to dig in to subatomic level. Basically whenever an electron (a negative charged sub-atomic particle) changes it's orbit, in the process emits high energy particles called 'Photons'
These photons make light. in ordinary light these photons are un-concentrated and released in everywhere thus ordinary light can not burn things just like that.

But laser is different than flashlight as:

• The laser is monochromatic. It contains one specific wavelength of light (one specific color). The wavelength of light is determined by the amount of energy released when the electron drops to a lower orbit.
• The liaser is coherent. It is “organized” -- each photon moves in step with the others. This means that all of the photons have wave fronts that launch in unison.
• The laser is very directional. A laser light has a very tight beam and is very strong and concentrated. A flashlight, on the other hand, releases light in many directions, and the light is very weak and diffuse.
  

Thus a 1W laser is way too more powerful than 100W ordinary light.

(Also a 100W light bulb doesn't emit 100W of light energy, it actually consumes 100W of power, and most of that power is transformed in to heat and very less into light)

[M4industries]

OOOOHHHHHH!

Laser BURN 

[SuperJesus]

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...

[CoolKoon]

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?

[von rad]

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.

R

[CoolKoon]

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.

[killajones]

Yeah, I'll show you how it burns...pull down your pants buddy ;)

[Big Bwana]

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..........

[paqrat]

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.

[Project D]

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.

[paqrat]

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?

[Project D]

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!