Introduction: 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.

Step 2: Making the Laser Pen

First take apart the pen and pull the tip out.
i used pilot mechanical pencil, better choice will be a pencil with metal case around the tip .
the tip will heat up occasionally and may burn the plastic around the tip.

Now cut the plastic isolation of the fiber to fit the pencil tip (be very careful not to brack the glass optic fiber) , thread the optical fiber in to the pencil tip and glue it with a small drop of super glue or epoxy .

As you can see the optic fiber is much thinner then the pancil tip about 50 times thinner.
so try to find very fine mechanical pencil and center the fiber in the tip.
sorry but i don't have any good idea how to center the fiber.

Step 3: Final Step

Now thread the fiber with the tip through the pencil. to finish the project put a small drop on the tip and glue it to its case. assemble the pencil and you are ready to run the diode !

Now you can burn everything :) Don't try it on your skin the laser will burn it immediately !

"NEVER LOOK DIRECTLY AT THE LASER BEAM AND PROTECT YOUR EYES WITH PROPER LASER GLASSES ! LOOKING AT THE BEAM WILL BLIND YOU INSTANTLY !!! '

The diode emits 830nm +/- 15nm laser radiation so you should use glasses that filter 750nm to 900nm radiation for your protection .