DIY Laser Torch

[Daedal]

So you want to make your own LASER?

Alright... Let's start with what you need to get this all done.

• Obviously, wires, solder, soldering gun.
• I'll leave the LD search to you (I'm using the equivalent of a 16x DVD burner red diode from the SenKat group buy.
• This Host (5W MXDL 2xCR123A flashlight)
• A few washers. I used 3 Fender Washers. One I had shaped to size personally and two 1/2" X 1-1/4" Fender Washers. Those were from the Home Depot for 7 cents a piece.
• Two CR123A batteries (3V, and if rechargeable, check the VOLTAGE before you put them in).
• AixiZ module.
• LM317 TO-220 package. Make sure the metal casing is not grounded! (I used the TO-92 package, but it's only rated up to 100mA and thus do not suggest that anyone else use it, but feel free to use it as I did.)
• Resistor pack or singles
• Patience and a light hand

 

[Daedal]

Let's start by taking the entire flashlight apart.

When you take it all apart, you’ll have the following pieces…

• The battery cap
• The battery tube
• The circuit/LED enclosure
• The reflector holder
• The reflector (not needed anymore)
• The glass lens (not needed anymore)
• The lens holder

The only item on interest right now is the little aluminum enclosure that is supposed to hold the circuit and the LED.

 

[Daedal]

Start off by pulling the little circuit out of the enclosure. The Circuit is simply pressed in. Grab a small flathead screwdriver or an exacto knife and pry the thing out of place. The LED is simply placed on there with nothing holding it in place. Desoldering the blue wire from the LED is all you’ll need to do to pull out the LED. It’s a nice LED, and they actually went hi-tech here and used Silver Solder on the joint so the wire wouldn’t desolder on its own from the heat of the LED.

Notice the “circuit” is nothing but a current limiting resistor. The resistor on mine measured in at 3-ohms. Which is WAY out of the 5% tolerance range.

Of course, desolder the resistor and note where the resistor was connected. On this circuit, there is one solder joint that is connected to the positive battery terminal and the negative it connected through the aluminum shell.

 

[Daedal]

So, you took everything apart… In the place of the lens holder try and place one of the fender washers. Notice how it closes on it nicely but it still wobbles all over the place. This is not a fine setup for a laser… So I decided to go one step higher. I bought whatever was the best fit for my uses (I got six fender washers from Home Depot, each measuring 1.25 inches outside diameter and .25 inside diameter, they were 7 cents a piece). I measured the AixiZ module and decided to drill two of them using my half inch drill bit so they fit the outside of the AixiZ module. If you have something more accurate, go ahead and use it.

 

[Daedal]

Here’s the fun part. I grabbed a drill bit slightly smaller than the AixiZ module, and with it I drilled the third fender washer. I then grabbed a flat drill bit and made the fender washer thinner across a half-inch diameter in the middle. Then I used a grinding bit and grinded the excess until I finally had a fender washer that would just barely go around the bottom screw-joint of the AixiZ module. The result is a washer that can be held in place using the lens holder, and it can hold the AixiZ module in place flat inside the flashlight housing!

 

[Daedal]

As you can see in the picture below… it works very nicely!

 

[Daedal]

For our purposes, we now have a circuit that we can do whatever we want with it, and place whatever we want on it, already made to fit this flashlight! So I grabbed one of my smaller LM317 chips and two 10-ohm resistors. The resistors are from the RadioShack bundle pack. I wound the resistor terminals onto each other from both ends to make one 5-ohm resistor rated up to a half an amp. I soldered that in place between the Adj and the Vout terminals of the LM317, and then I soldered the POSITIVE LD wire to the Adj line. Yes, the same place where the resistors attach to, you can just use the same piece of solder.

MAKE SURE YOUR SOLDER IS CLEAN. MAKE SURE THE TERMINALS ON THE LM317 ARE NOT SOLDERED TOGETHER. MAKE SURE NOTHING IS GROUNDED INSIDE THE CASE.

From here, I connected the LM317 Vin wire to the junction on the circuit that corresponds to the positive terminal. Then I connected the ground wire to the ground. I connected the ground wire to a spot on the circuit board that connects to the designated positive terminal on there. It’s the one that connects to the outside ring on the bottom.

 

[Daedal]

If you connected to the PCB like I did and is pictured above:

After pressing the ‘circuit’ in place, it’s important to connect the outside ring to the aluminum body if you connected the wire like I did. You can just place a small piece of solder on the edge, or press a small wire between the PCB and the aluminum housing and then bend it onto the outside ring.

At this point it is smart to connect a DMM in there, place the batteries inside, and try it out to make sure things work.

 

[Daedal]

We now have 2 wires coming out of the aluminum enclosure and heading towards the front of the flashlight. Start by placing the LD into the AixiZ module, preferably using Arctic Silver, then cutting the third pin coming out of the LD. Then place the capacitor and the 1N4001 diode on the back of the LD.

MAKE SURE NONE OF THE CONNECTIONS OR LD TERMINALS ARE TOUCHING THE AIXIZ MODULE WHEN YOU CLOSE IT. There’s plenty of space in the AixiZ module, so you should be fine.

 

[Daedal]

Then place the bottom of the AixiZ module through the wires, then place the fender washer somewhere so that you can still access the wires. Solder the wires in place and make sure you don’t mix the positive and negative wires. Again, and before powering it up, make sure the AixiZ module is not touching anything while you are closing it.

 

[Daedal]

So now tighten the AixiZ module, adding Arctic Silver if available, and test it out… This should be interesting

 

[Daedal]

Place a couple more fender washers on top, then tighten the lens holder. While tightening make sure you don’t turn the AixiZ module in the process. This could snap your wires, or create some unwanted connection somewhere inside

At this point you are probably the happy owner and maker of your own home-made burning red laser! I will provide a video of this thing burning, and it is one hell of a burner.

I hope you all enjoyed it and good luck making your own. If you need anything please do not hesitate to ask. Suggestions and comments are, as usual, very welcome.

GL;
DDL

 

[Daedal]

The Kill Point is now on... I'll see you all later

Hope to hear from you all soon;
DDL

 

[Rhith]

Holy amazing! I wish I was patient enough to do something like that... I'm just going to stick with a riverrock from target for my first DIY red..

 

[Daedal]

Here's a quick video I just snapped a little bit ago... I know... I have a very shaky hand and I can't keep the laser in place worth a damn, it still burns FAST thought! ;D

Hope you like it;
DDL

 

[stevetexas]

Another great DIY laser and as always - great explanations!!!