Intro: Homemade Laser Pointer
Step 1: Materials
What i needed to make that laser is:
- A laser diode, I used visible red diode, but you can use the color you want (or the one you have)
-LM 317 voltage regulator
-2x 10ohm 1/2w resistors
-1N4001 or somilar diode
-One 100nF capacitor
-A 100ohm potentiometer
-A push button
-The PCB (step 2)
-A case (step 4)
-A focusing system (steps 5 & 6)
Step 2: The Driver
To make a proper driver for the laser diode, etch the PCB and solder the components as shown in the diagram.
Some people only connects the LD with a resistor in series, but that driver is a better (but more expensive) way to use a laser diode.
The LM371 varies the voltage the LD uses (i cutted the top because it didnt overheat, i think i does not affect the way it works), the two 10ohm resistors in parallel set the maximum voltage and current the Laser Diode will get, the pot allows adjustment of output current, The 1N4001 diode protects the LD from a negative input as battery placed wrong, but LM317 can't deliver neative voltages, so maybe it is not necessary, and the capacitor protects laser diode from immediate power supply especially when switching on.
This driver is a mixture of what i have seen arround, so, if something should not go there, please tell me.
Step 3: Plug to Battery
I had an old battery, and when i thought i was going to use a 9v battery as power supply, i decided to use this one as case and plug.
After you open it, if it is new, use the batteries inside, don't throw them!
I soldered the battery plug to the circuit input, making sure it was correctly polarized.
Step 4: The Casing
As i've said, i used the old battery as a case for the driver, i sanded it and i drilled some ventilation holes because i cutted the top of the LM317 regulator.
Maybe you like to give it a paintjob, but i decided to leave the metal polished.
Step 5: Laser Housing
That two steps are a guidance for you, because i used parts that i had on hand, that sure you don't have, you have to improvise, or buy a laser housing with its lens.
Step 6: Focusing System
For the focusing system i used a potentiometer threaded part and its nut and a salvaged lens from the dvd reader.
It is not perfect but it focuses the beam ad it's free!
Step 7: Putting It All Together
I connected the driver to the laser diode and after making sure it works, i insulated the driver with tape, i introduced it into the case and i glued it to prevent pulling it out with cyanocrylate, But epoxi would work better.
The laser housing was hot glued making a diode replacement easier.
Step 8: Done!
The laser pointer war finished and ready to use, my little brother is now happy with it's new pointer and the cats in the street :3.
The laser reaches 150ft if you focus it well and it is about 5$ in materials and made by yourself!
If you liked my instuctable, please, vote me in the Epilog laser, pocket-sized electronics and battery powerwed contests.
If i win the laser cutter, thing that probably will not happen, I'll use it for engraving everithing i can, for cutting gears, cases, 123D kits... It would be totally awsome!
Feel free to ask me anything you didn't understand or propose upgrades.