Easiest Way to Make a Laser Burn




Introduction: Easiest Way to Make a Laser Burn

Ive always been fascinated by lasers they are just such neat devices, the only problem is after a while you get a little bored just shining them at things. I always wanted the 007 laser that will just slice through anything, while this instructable wont give you that but it will let you easily slice through the black trashbag or electrical tape that Dr. No has tied you up with. All you need to be able to do it is a cheap 5mw laser from ebay and a small lens.

Dont expect crazy amount of power from this just enough to make dark plastics smoke, pop dark balloons from close range, and maybe if youre lucky light a black match.

Step 1: How It Works

Seeing this diagram might help you understand why a lens will seemingly increase the amount of power a laser puts out. Its clear that it doesnt actually increase the amount power it just focuses it at a specific point, this is one drawback to this burning method because your laser wont behave like a normal laser point after this because past the focal point your beam will diverge, acting more like a flashlight. This is why I wanted to make my lens attachment removable so I can go back to a normal laser pointer whenever I want to.

Which laser to use? In my experience the best bang for you buck is to get the 405nm blue/violet laser not only does it look awesome, change color when it hits light colored clothing, and light up glow in the dark objects, but according the second diagram because its wavelength is shorter it also has higher energy than the other two. However another thing to consider is the mW's your laser produces I believe given the same mW a violet laser will burn the best but a 40mW green is probably more powerful than a 5mW violet. Its really up to you, what you have, what you want to do with it, what you want to spend, and whats legal where you live. I found all three of my lasers for $15.00 on ebay so decided to try all three.

Step 2: Parts

To make a burning laser the most important part is the laser, I got three; a red, a green, and a violet/blue. They are all rated at 5mw although I do not have a meter to verify this. Wavelengths are 650nm, 532nm, and 405nm respectively.

The other critical piece you will need is a lens, I am no expert but I believe the lens should be convex I explain in the why it works step.

The last part is how you will attach the lens to your laser I show two ways in this instructable first is the dead simplest just electrical tape it onto the end, this is the fastest way to get burning and is a good thing to try out if you want to decide if its worth it making a better mount.

After playing with the electrical tape I decided I wanted a nicer looking and more durable yet removable attachment method so I turned an adapter out of delrin on my lathe. You can really use your imagination for this part, you can use anything you have around you, in one of my videos seen in the last step you I made an adapter out of an old magic marker.

Step 3: Get Your Lens

Find a source with a relatively high quality convex lens plastic is preferable but glass will work also(thanks merlinjim). It only needs to be as wide as your lasers beam. I found that the front lens on these same cheap ebay lasers works quite well so I found a dead green laser and using needle nose pliers simply unscrewed it.

Step 4: Attachment (electrical Tape)

Dead easy, just line up the plastic housing and tape away. Electrical tape is nice because it holds strong enough and looks decent.

Step 5: Attachment (delrin)

This creates a much more professional look but in turn requires much more work, the nice thing is it is easily removable and can be used on any of these lasers.

The design varies based on the type of lens you use and what size it is, for me I just cut the lens off of the rest of the housing and drilled a hole for it in the delrin. Then I bored a hole that was a loose press fit onto the silver part on the front of the laser, it was a fun and easy project because delrin is so nice to machine.

In the final picture you can see magic marker lens holder a made a few years ago, just to show you can make just about anything work.

Step 6: Burn

Now that youve mounted your lens its time to burn some stuff. First video shows the three lasers in this instructable and the second video is my older one that shows some fun you can have with it. Be carefull while doing this the beam is very focused and that light that bounces off could easily blind you.

In the first video it appears that the green is the weakest this is because I had been using the green the most and wore the batteries down.



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    48 Discussions

    Nobody will ask you the mw calculatings of this device. Because they don't know how it works. So don't be afraid.

    how to make small laser hair removal machine. Like this handy machine or veet laser hair removal machine

    how to make small laser hair removal machine. Like this handy machine or very laser hair removal machine

    Because the color "black" absorbs light and the color "white" reflects light. That is why it looks brighter when you point a laser at a white material and dimmer on a black material. I hope this was helpful to you.

    Black is not a color but the absence of one..

    Actually....black is the presence of all primary and secondary colors of the spectrum

    because dark materials absorbs all light energy (almost no reflection )

    A convenient slide on/off button on the barrel activates the torch. A long or little case trimmer base might be essential for very short or long rounds. A flashlight will travel in handy while you are camping, you will find everything you need at a reduced price with fast shipping too. I got this code "PD10" and got a 10% discount. http://patriotdeal.com/products/green-laser-pen

    will a magnifying glass work for lens

    will this laser diode work


    As far as the source of lens, people often get high(er) power laser diodes from DVD-RW drives (my personal favorite source :) ) and there's plenty of lens in there. So, you get both the laser diode and the lens from the same drive.

    I had to put together a housing for an odd-shaped laser diode some time ago (the attached image) and had some pictures taken to illustrate where the lens are located. See the post about DIY laser diode housing here . It describes the process based on a different set of parts (literally, hardware store, plumbing section) but the lens may still be useful in a hand-held build like yours.

    As far as the burning ability of the diode, it greatly depends on the color of the material. Until you get into 1W+ ranges, there's no way it'll burn anything that has the same or similar color as the laser beam - it just reflects too well. Black is always the best. And I would say that you can start doing some useful burning (such as CNC foam cutting and engraving) at about 150mW or more. Pretty much the power of the diode from a DVD-RW drive, again.

    Keep the great instructables coming!


    3 replies

    I bough a 100mw 405nm laser module with the idea of attaching it to my vinyl cutter and using it instead of a blade. Unfortunately I didn't realise I had ordered a line laser by accident. Do you think it will work as a dot laser if I just remove the lens or do I really need to replace the lens to get a focused dot small enough to burn? And is 100mw enough? Does a laser like that require safety glasses? I've seen ads for laser pointers with the same specs...

    My module:


    Same spec in a laser pointer:




    You can't just remove the entire lens but you may be able to take it apart and remove just the line lens (should be a tiny cylinder-shape lens with its side toward the light) and leave the collimating part in. I honestly don't know if it's even possible in this module - you'll have to take a closer look when you get it. 100mW laser ABSOLUTELY requires safety glasses for the specific wavelength - 405nm.

    Unfortunately, as a cutter 100mW laser probably won't do much. I've played with 200mW red ones and basically all I can cut is 3mm black craft foam. You should still be able to cut black craft foam with 100mW but very slowly. Definitely not a material that's more dense than craft foam and almost certainly no other color but black.

    Also, I hope you realize that you cannot cut vinyl by laser ablation because you are going to release chlorine fumes - nasty stuff, good for neither you nor the equipment.

    Thanks for the info - I wasn't planning to burn vinyl - the cutter handles that fine already - but I would like to cut 2mm coroplast which the cutter can't handle.

    Unfortunately all my DVD writers work - no dead ones for spares...