Simple Laser Show




About: Currently looking for a summer internship in engineering! Interested in everything from djing to trebuchets, coilguns to kiteboarding. I am an avid skiier, and am currently studying integrated engineering. ...

Fist, the disclaimer: I am not liable for any damage you cause to your eyes or any other part of your body, someone else, or anything by reading this Instructable. Lasers are dangerous, and they will permanently damage your eyes if used incorrectly. do not get any laser above 30mw, unless you are experienced and familiar with the risks of a stronger laser. do not point the laser at anyone or yourself.

Anyways, this is a simple laser show i thought of when I was trying to diffuse an led and i heated a piece of acrylic until bubbles formed. When i got bored of testing led diffusion methods, i shined a laser through it and noticed a nice, 3-D pattern. I decided to utilize this and make a laser show out of it. About 30 minutes later, i had a nice looking laser show. I tried to make this Instructable as easy as i could, please comment.

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Step 1: Materials

You will need the following: 
- A laser pointer or module, see This. don't get anything above 30mw!

- A bunch of legos, make sure you have a motor, a battery box or power source and a worm gear box. (any small, slow speed motor will give you good effects).

- a small piece of acrylic at least 1/8th of an inc thick (available at home depot or Lowes, or pretty much any hardware store). be sure not to get polycarbonate, it turns black or tints when heated, which is not what we want.


the tools you will need are:
 - a drill + drill bit
 - Saw to cut the acrylic
 - a heat source
 - something that i probably forgot to mention

Once you have all of these things, you can move on to the next step.

Step 2: Preparing the Acrylic

To make The laser diffract and make those cool patterns, you will need to shine it through a special acrylic plate. To make this acrylic plate, you will need to take a small piece of acrylic, no thinner than 1/8th of an inch, and heat it until it forms bubbles.

However, you cannot just heat the acrylic with anything, because something like a candle will just char the acrylic and make it very dark, which will result in a very dim laser effect or none at all. You need to use a clean-burning heat source, such as ethyl alcohol in some heatproof metal container (be careful with this as you cannot see the flame in daylight and if you try to put it out with water, it will just spread the flames!), a heat gun (i got mine at harbor freight tools, $20 or something), or a gas stove.

Cut yourself a small piece of acrylic, about 2 by 2 inches. Carefully heat it until you see bubbles appear. A good idea is to hold the acrylic with pliers. Be careful not to set the acrylic on fire.

After your bubbles have formed, set it down on a  heat-proof surface and wait for it to cool. in the meantime, try to find a drill bit the size of a Lego axle. if you cannot find the right size, get something slightly bigger and wrap tape around the Lego axle to mount the acrylic securely.

Step 3: The Lego Frame and Drive System

The Lego frame is the Main part of the whole Project. Build what is described in the picture. it is allot easier than it looks.

Step 4: Final Things...

now all you have to do is hook up your laser to your  power source or turn it on. Then, start the motor by connecting the battery box, and dim the lights. project the laser beam against a wall and enjoy the 3-D patterns!

currently trying to get the video up.

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    10 Discussions

    The Freak

    5 years ago on Introduction

    Nice idea! I like the weird wavy paterns, especialy since you use such a simple method to make it. You don't need any fancy special reflector bla bla bla, just some acrylic which can be bought in every country in the world. Do you happen to have the video somewhere? And why do you say don't use a laser stronger then 30mW? Because I happen to have a green module of 70mW which I would like to use.

    3 replies
    biolethalThe Freak

    Reply 5 years ago on Introduction

    Hmmm this project has long been disassembled, and I don't think I had a video of it, sorry! I guess you'll have to build it to figure out how it would look! :)

    I recommended nothing stronger than 30mW because of safety concerns, lasers can be dangerous and will blind you instantly! Sure, you can use your 70mW laser, but you'll have to be very very careful or even invest in some laser safety goggles, and never point the projector at people! You only have two eyes, and they are quite useful in this day and age :)

    The Freakbiolethal

    Reply 5 years ago on Introduction

    Ok no problem ;) Ok just safety, good. In my opinion any laser of 1+ mW is dangerous, so I wanted to point it at the ceiling anyway. Also put it inside some sort of enclosure to prevent scattering rays from blinding people.


    9 years ago on Introduction

    Yeah, my friends and i are trying a multiple laser design


    9 years ago on Introduction

    Not a bad little instructable, and a very neat way in using lego's.

    I was thinking if there was a way to do something like this only have it in a case with interchangeable effects, would be quite cool to see.

    4 replies

    Reply 9 years ago on Introduction

    it is possible, it would just need to be a little more complicated and use more electronics, because you would have to either use multiple lasers or mirrors to deflect the beam into the different effects. try diffraction grating for many beams and round acrylic/glass rods for a line effect. also, the classic spirograph could be used. if you are really into electronics you could use galvos or something like that, which can be driven by computer software.


    Reply 9 years ago on Introduction

    Neat. I was thinking of tying in a few lasers of different colors into an arduino along with the motors to control each one of them. Would be really neat and could easly be modded or upgraded.