Instructables
Bouncing a laser beam off a mirror rotating at any angle above 0 degrees will create the illusion of a circle to the human eye. Combine two rotating mirrors, and complex shapes begin to emerge. With every additional mirror, the perceived image becomes more complex and intricate, with the ability to create some very beautiful and bizarre flowing patterns of light.

Most laser spirographs consist of only two mirrors, limiting the complexity of their shapes for the sake of easy construction and bulky size. I have seen various guides on the net about three mirror spirographs, and after creating one figured I would up-the-ante: a four-motor spirograph in a compact box which is portable. This design will accept the use of any pen-style laser pointer, and through the use of potentiometers (variable resistors) to adjust the rotation speed of the mirrors, new shapes can be created. The benefit of using a laser beam allows the image to be projected to any size, on an indoor wall, an outdoor tree, through a lake/pool, snow, or the side of a building.

I hope you enjoy creating and sharing this display of light, which myself, friends, family, and strangers alike have been drawn to the limitless shapes created through exploiting human persistence-of-vision.

This is a rather complex mod. I'm already assuming you know how to solder, and have some basic understanding of wiring. Though you definitely could complete this mod as a first project, it will be rather confusing and challenging.




This violet projector made by user JoeMonkey from following this instructable -- Awesome job Joe!



***WARNING - SERIOUSLY, I MEAN IT, READ THIS ONE***
Laser light while very enjoyable can be extremely dangerous, dangerous to the point that most people don't understand the numbers of how powerful 10 mW (milliwatts) is, much less 100 or 500. While many projects have unnecessary warning labels, the concentrated energy from a laser beam really can blind the eyes of those who look into it's beam. Realistically, any laser with a power over 10mW (3.84mW is the power at which human eyes begin to be damaged) shone directly into a persons eye will de-nature (boil/cook) the rods on the back of their retina. This becomes a big problem if a person looks directly at the beam, as their center of vision will be damaged, inhibiting reading and other fine viewing permanently. The damage comes because the lens of the eye focuses light so precisely, what was 10 mW ends up becoming 80mW since it's focused on such a small area of the retina. It sucks to have your vision ruined for life for a toy. That being said, the cheap crappy red laser pointers for $2 tend to output about 0.5mW, and won't ever hurt you.

Second, don't shine a laser at anyone who doesn't want one pointed at them. In multiple states pointing a laser beam at a person is equivalent to assault with a knife. Many people have an irrational fear (thanks to being portrayed inaccurately in movies and television) that a laser beam is associated with a firearm, as such ignorant people fearing for their life can earn you a trip to jail. This includes pointing laser beams through people's windows, their car, or even simply near them, people are fearful.

Third, never point a laser beam at any aircraft or helicopter. These vehicles often use polycarbonate for their window "glass", and a laser beam anywhere on the window will scatter through the entire surface making it impossible to see out. Pilots take laser beams very seriously, and the government crackdown in the United States is especially strong. I personally know a friend who has been given a $1,000+ ticket and criminal record for pointing a 5mW laser at a police helicopter. Though the real life danger for pilots is minimal and over-hyped, government over-reaction to laser beams is not.

Fourth, eye damage from lasers usually happens without a victim immediately recognizing anything ever happened. A single flash from a 100mW might make you flinch and say, "Wow, that was lucky". In reality, you just toasted a line across your retina, but other parts of your eyes will compensate your vision to the point you don't notice. With multiple exposures (though really, a single 200mW+ exposure will truly screw you up), eventually the damage will accumulate, things become blurry, and you can't read.

Now with all the scary stuff out of the way, let's get to building!
 
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thepelton4 years ago
One thing I saw used in a laser light show was to fire a laser at a small mirror attached to a cheap speaker. The laser would bounce along in time to the music. What I was thinking is: What if that beam had already been turned into a circle by a rotating mirror?
QuackMasterDan (author)  thepelton4 years ago
Believe it or not, I have done that exact thing, thinking how awesome it would be. I have attached a below picture of another laser project, where a laser bounces off a mirror glued to a speaker, and passes through a transmission matrix diffraction grating (complexo-speak for turning one laser beam into a thousand duplicates). That picture below is of the speaker being plugged into my television, and projecting onto my ceiling. As for how it turns out blending them. You get a blob. A big, fuzzy, random green blob. It's pretty underwhelming, but it is a laser project, so you could still show it off to some unknowledgeable newbie and have them be amazed ;)
IMG_0018.JPG
I like doing that sort of things in a really dark room after getting a sugar / caffeine / sleep deprivation induced high.
QuackMasterDan (author)  Kryptonite4 years ago
It's even better when you combine the sleep deprivation, stimulants, laser lights, and some solid electronic trance music.
Ever heard of Anger Fist? That's my favourite trippin' out past 3 am music.
QuackMasterDan (author)  Kryptonite4 years ago
I have friends who greatly enjoy his music, they tell me he has some really original sounds and track structures, and successfully blends old (early->mid 90's) urban sounds with modern hardcore techno. I looked up some of his stuff, however, most gabber is still too hard for me, except maybe DJ Kurt, Teranoid, and Scott Brown. As far as tripping out music for sleep deprivation, check out psy-trance, songs like Bust a Move and Mush Mushi by Infected Mushroom, LSD by Hallucinogen, and Solid Electronics and 1,000,000 Years From Today by Astral Projection. All those tracks are designed to help druggies on LSD and MDMA enhance their trip, since I don't do any intoxicants, I find the music itself to be mind-blowing.

Adoration to the aum trancewave... early 90's very yummy till today. Check out Matt Bukovski he has some really good tracks out there.

Whoah, that does sound trippy.

Thanks. For a non intoxicant alternative, go for triple chocolate ice cream (the real stuff) with just as much ground coffee beans and crushed Tim Tams. A personal favourite.
I've read through your project and wondered how big of a shape does this make? Is it a large shape if you use it from the other side of the room? Any suggestions as to if a cheap store bought laser pointer will work as well (not a lot of available funds)? Thanks!
QuackMasterDan (author)  madman3566474 years ago
Fairly big. From a distance of about 10' away, the projection is around 1 1/2' wide. From about 20' the image is around 4' wide. It expands pretty quickly, you can easily manage how big you want it to be with the distance you stand. As for a cheap laser pointer, I have never heard of any brick and mortar/real-life store that sells cheap green laser pointers. I linked to LEDShoppe.com which sells 5mW lasers for $12. And Rayfoss has some very cheap ones too. What is $12 online I have seen for $90 in a real store. I can only suggest purchasing them online, as you'll save so much money, on top of getting a better product. If you absolutely must have a laser pointer today, and are willing to get ripped off, go to The Sharper Image, any Maps/Astronomy store, or if you have one, a local specialty light and toy store.
why does it have to be green?
QuackMasterDan (author)  gruffy4 years ago
It doesn't have to be green, you can use any color you wish. Lasers are measured by mW, and depending on their wavelength (color), it's harder to make more intense light. A red laser beam is much cheaper and easier to create than a violet one (the red wavelength is much longer), so you can find a 100mW red for around $80. Purchasing a 100mW violet may cost $800-1600 depending on where you look (though some hobbyists build their own out of PS3 blu-ray drives for much cheaper). I use green because it is the most bang for your buck. Human eyes are most sensitive to a turqoise/green color, and mW for mW, green lasers appear much brighter. A 20mW green can appear about (guesstimating) 5 times brighter than a 20mW blue, despite them being the same power. As for your second question about faster motors, I find that you get more interesting patterns with slower speeds actually. It's all semi-random on what patterns you get with the combinations of mirrors. Faster speeds can do two things: 1) make your patterns shift much more quickly (and be harder to control); 2) when multiple motors are running at very-high speeds, if you can get a stable pattern to be created, you can get some extremely intricate/complex shapes, more-so than with slower speeds.
Thanks for the in depth reply. At first I was thinking of using all high speed motors but you've changed my mind. I may, however, incorporate a fifth optional high speed motor just for kicks. I'll post pictures if I make it that far. also: http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html ^Your point about green wavelengths (at least in the dark) is confirmed above.
QuackMasterDan (author)  gruffy4 years ago
You are correct, that 507nm is the wavelength human eyes are most sensitive to at night. Why 507nm? That is the average wavelength of reflected light off the moon passing through the atmosphere at night. If you look directly at the moon, you may say it looks white or bluish white, however snag a spectroscope and the colors will be more in the green area of the spectrum. In short, it helps you make the most of the limited moonlight for activity during night.
cool! it's amazing how that trait evolved.
QuackMasterDan (author)  gruffy4 years ago
I imagine all the genetic branches with 510nm sensitivity were eaten by tigers or bears while roaming around at night-time ;D

Lol that made me have to clean up my computer screen... dont drink coffee and read that comment.

hahaha! My crazy idea is that all the genetic branches with 510 nm sensitivity fell into chasms.
gruffy gruffy4 years ago
Wow I'm glad instructables reformatted my comment...
gruffy gruffy4 years ago
i'm so excited to try this build! what effect does a faster motor have on the image?
namphibian3 months ago

Busy looking at doing this project I did a basic prototype and it is working brilliantly. However I had a question about the laser duty cycles. Most of the laser all have a 3-5 minute on duty cycle and then a 30-60 second off duty cycle. Now from my understanding this is due to heat build up in the diode. How did you handle this? Is it possible to perhaps extend this duty cycle with a attached heat sink?

QuackMasterDan (author)  namphibian2 months ago
Major kudos on the project, glad you have made excellent progress :-)

You are correct, most laser diodes have a duty cycle of under 5 minutes, after which the need to cool down. The heat may not necessarily be conducted to the diode housing, the heat is stored internally. Too much heat weakens ("cooks") the diode. Fortunately, most laser diodes come in a metal housing that can be removed and attached to a heatsink. The higher power the laser, the quicker it cooks/degrades.

A heatsink with a FAN is the most common way to extend the life of the laser. Purchasing a laser heatsink tends to be fairly expensive. The best solution I've found is either a) mini-motor heatsinks, or b) CPU heatsinks and boring out the center to the diameter of the diode housing. You WILL need a conductor between the diode and its heatsink, just smother the heck out of the diode and heatsink with thermal paste. The other good option is to purchase a laser in which the structure itself (handle that contains the battery) is metal and acts as a heatsink. Lots of surface area! With a CPU heatsink w/ fan, I would feel comfortable using up to a 250mW laser for an hour or two. With that said, ANY laser should not be run indefinitely, no matter how good the cooling system.

This is by no means technically correct, there will always be degradation when a laser runs for an extended period of time, but in practice, if the laser is under 100mW you don't need to worry about duty cycles if they are shorter than 20 minutes. Duty cycles become dangerous to the point of frying diodes when high powers are involved, or for extensive amounts of time (think measuring in hours for a continuous night-time display).

Hope that helps, and thanks for asking!

Ok so at least I was thinking along those lines. On another note I have managed to find a way to almost perfectly mount those pesky mirrors to the motors. Some balsa wood with the front cut at 1-2 degree angles and the laser projection is much much sharper and defined. Will put together a video for it once I have refined the technique a bit. Never thought my wood working lessons from my Grandfather would be so useful in this project. This project has sparked something in my 5 year old daughter and we are now having science lessons everyday so I can explain to her how things work. Wish I could see through her eyes for a moment as this appears completely magical to her. Thanks for the reply.

ananda12 years ago
How would one integrate a spirograph into a party SAFELY? Would you aim it at the air, a wall, the ground? Lawyers are expensive.

As long as the laser beam is moving ("scanning," in the parlance of lasers) there is no danger to anybody's eyeballs. Even the relatively dangerous green laser (as opposed to the common red, and I'm only talking laser pointers here, mW-wise) requires over 1/4 second exposure to the direct or reflected beam, and this just doesn't occur with the laser point whipping by so quickly that it appears to be a line. :-)

jtovar932 years ago
Hi all,

I want to do this project but I can not find 100 ohm potentiometers, the only ones I am able to find are 100k (which atre not the same, right?)
I would be very happy if someone helped me out on this.
agr00m2 years ago
I've actually had this one finished for a while now based off this project. I think it turned out very well. I'm in the design phase of making a 2nd "smarter" one that utilizes a micro-controller. This way I can use it to PWM out to the motors (through a motor driver) to get consistent use each time, have a digital display showing the speed of each motor and have the ability to save pre-programmed designs as well as have a random mode that just does random designs. I'd also like to implement a speaker to so it interacts somewhat with the music being played.

Here's a demo: https://www.youtube.com/watch?v=MXodmgpdcgA&list=UUDADfKyYBMH_d9r3L4t3-8A&index=6&feature=plcp
Hi! I'm doing this spirograph as an honors project for physics II. (Thanks for posting it, btw) Your instructions are written beautifully and I have learned a great deal about parts, tools, and methods while making this. My goal was to learn how to solder, which I have... but also a whole lot more!

Anyhow, my only stumbling block has been in placing the motor-mounted mirrors. Could there be an easier way to place them in the box other than hot glue? I find the need to adjust them as I work down the line and pulling them out gets messy and risks knocking off a mirror each time. My professor suggested that I use air dry clay (which helped with the slight z-axis angle from the cone shaped projection) but when it dried and I went to glue it permanently down... it moved out of the desired position.

I really knew nothing about any part of this kind of thing when I chose to do this. I had a drill, hot glue gun, and pliers when I started out, lol. :) This has been a fun and rewarding experience so far... I just want to play with it now! Do you have any suggestions for me? Should I trace around the bottoms of the motors in the box to help line them up? Maybe there is a defined angle arrangement that always works? Will they automatically line up if I'm playing "Dark side of the moon"? (wouldn't that be cool?) I usually miss the most obvious things... thank you so much for any kind of input you have!
QuackMasterDan (author)  mechanicalities2 years ago
If you wanted to make it a bit easier on yourself, you can try using 40mm Case Fans from newegg. They're dirt cheap, but they run at 12v instead of 3v like hobby motors. Much, much easier to align and work with, but they're bigger. You can throw a folded piece of paper or a shiv underneath the mirror, and have a nice, stable surface to glue it to. I've seen someone put a mount on them and bolt them from underneath the base whenever he needs to move them.

If you want to adjust a mirror because you glued the motor in the wrong spot. Throw the box in the freezer for a good 20-30 minutes. Then with wide-grip pliers, grab and do a rapid twisting motion. You'll very easily and cleanly snap off the hot glue =].

For mounts, there is an absurd amount of RC Airplane mounts for 3v hobby motors, they're semi expensive though, like $5-8 per motor, but, they're solid. I'd definitely mark where you want to put them with a sharpie.

I made a picture detailing the *ideal* layout if  you have enough space. I hope it helps.
pewpewpew.jpg
I looked at those case fans and they look like they will greatly ease my troubles. I like having something solid to glue the mirrors to and a shiv sounds much nicer than my inexperienced eyeballing ability. You are a genius! I'm ordering them today. Also, I'm using 100ohm 2W pots for this... will I need to add a resistor or something since the fans are 12V? Might it limit my shapes or shake off my mirrors if I don't?

I hadn't thought to put the box in the freezer either, so thank you for that tip. I have quite a bit of glue residue that I can now eliminate. :) I look forward to trying your 108 degree ring out too. I think my conduit box is larger than the one you used, so I might have the room to have it work. It will be way more easy to mark the fan placement than it was ompared to my lumps of air dried clay.

I'm really glad that I asked here about this... you've made my day! Thanks again for your help.
I DID IT! It's done. Thank you so much for your input, again. I needed to keep thinking it through and your response encouraged me to do so. :)



I didn't have time for the case fans to come in from China before I needed to turn in my project, so I had to improvise. I took some wick tabs from the bottom of cheap votive candles and soldered them to the tip of the motor. That gave me a solid surface to glue the mirrors on to. Also, the tabs are somewhat flexible and I could adjust the tilt after putting them on. That enabled me to use Lego's as the motor stands, since my tilt wasn't so large.



I'm really excited about this working, it is the most intricate project I've ever made and EVERYBODY loves playing with it! I have to let my teacher keep this one and I've already started my second one (for me to keep). I'm trying your 108 degree model and it really seems to be working great. You have made the the envy of my pre-engineering classmates, lol. I'm already enrolled in the fall electronics engineering program, after enjoying this project so much. Thanks for the help and the inspiration, man! :)
QuackMasterDan (author)  mechanicalities2 years ago
Glad to hear it worked out so well, that's a major reason I write these guides, is to encourage others to push themselves and have fun learning. Not to mention the often very-cool projects they tend to be ;D.

If you really want to have fun with it, use it outside on a foggy night, or throw up some dust or make smoke and fire the beam into it. We've had a few campfires were people have fun pointing the beam up into the rising smoke, and it's pretty mesmerizing.

If you make anything that's cool or a video or have pics, please show them to me. It's always neat to see the work of others, often you guys tend to improve upon my designs in ways I never would have thought of. Keep up the great work!
Electorials3 years ago
Really awesome!

I made this one, and it works perfectly!
It makes some really nice pictures, like rotating 3D shapes :)

The only problem is that the hot glue doesn't hold the mirrors when they're rotating really fast.

Great project!

Thanks
I made the spirograph just like your instructable, only the lay-out is different.
It seems to work really great now! the glue isn't a problem anymore ;)

Thanks for the instructable!

i found the area around 2:30 to be particularly awesome.
QuackMasterDan (author)  Electorials3 years ago

Excellent work! I love hearing that my guides have helped other users, and it's especially exciting when you guys modify my designs! Thanks for the video too, your projector turned out very nice. I hope you get to share your creation with many friends and onlookers, and maybe enlist a few more modders into the laser-building ranks. Keep up the good work, if you make anything else cool, send me a PM, I'd like to see it.
Hello,

What do you mean with "laser building ranks"?

And I'll let youknow when I make something new ;)


Greetings,

Electorials
Just got mine done and posted it today!
http://www.instructables.com/id/4-Motor-100mw-532nm-Laser-Spirograph-Budget-Build-/


Thanks for sharing your's with us!!!!! It was the push I needed to get one built.


I think I've been hit by the laser bug and hard at that. Over the past 3 weeks I've been preoccupied with all aspects of the working laser...Ive purchased The Arctic 3 by Wicked Lasers and several turnkey laser projectors and scanners by American DJ. With that being said It's no surprise that I must build one one now. This project is great and just what I was looking for as a my standard for this first attempt. Please, I'm open for any and all suggestions that may help me actually achieve this
Thank you and look forward to being a part of this forum.
Regarding how to adjust the wobble: do a google search on "harmonograph" and see if that gives any helpful pointers.
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