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Laser Kaleidoscope

Laser Kaleidoscope

We managed to get Milwaukee Makerspace invited to another gallery night, and this time we’re taking part in Bay View Gallery Night at Alterra, so I figured I needed a new project. And hey, what’s better than a deadline to get a project done? (It’s like college all over again… in a good way!)

Interociter

When I was at Maker Faire Detroit back in July I saw this laser spinner thingy called “The Interociter” and decided I had to have one. And by “have one” I mean “make one”… so I did.

(There’s some debate over whether it should be called a “Laser Kaleidoscope” or “Laser Spirograph” or “Laser Spinner Thingy” and while I do like “Laser Spinner Thingy” I also get sick of people thinking all my projects are Spirograph-inspired, so I went with Laser Kaleidoscope. Deal with it.)

Laser Kaleidoscope

Laser Kaleidoscope

So where were we? Oh yes, the project! It’s really simple: a laser is pointed at a mirror, and that reflects the laser onto another mirror, and that one reflects it onto another mirror, and then it shows up on the wall. You can make the motors spin by turning them on with a pushbutton, and then adjust the speed by turning the knobs. There are 3 motors (an earlier prototype had 4) and by setting them all to different speeds, you can get some crazy patterns going.

So how does it work? The laser hits the first spinning mirror, and creates what appears to be a circle. It’s really a single dot, but it’s spinning around so fast it looks like a circle. Add a second (and third) mirror, and since they all wobble just a little bit, you get much more than a simple circle.

Here’s a shopping list:

I say “shopping list” because those are the parts I (mostly) bought… Of these parts I’ll note that with the laser I leaned towards the “safe” side, but it can be difficult to see in well-lit rooms, so I may upgrade to this one at some point. The round craft mirrors came in a variety pack with different sizes. I may experiment with larger mirrors in the future.

Laser Kaleidoscope

Laser Kaleidoscope

There are a bunch more parts involved, one being the piece of wood everything is attached to, and the other parts were all designed and 3D printed by me. (OK, I had a little help with the knobs.)

The printed parts are:

  • (1) Laser mount
  • (3) Motor mounts
  • (3) Mirror mounts
  • (3) Knobs

(I also considered printing some small U-shaped things to hold the wires in place, but haven’t bothered with that yet.)

And yeah, this is why I have a 3D printer. The ability to digitally design something, rapidly create it, tweak it a bit and print a new one… that’s what I love.

My original plan was to make up a nice laser-cut case for this (I thought that would be appropriate) but with the lasers down for repair, I didn’t get that done in time. That’s actually fine, as I’ll probably end up redesigning things a bit before I’m totally done with it. So far though, I’m happy with the progress.

The video was quick & dirty, and really doesn’t do it justice, which is why you’ll need to come see it in person I guess. I figured I couldn’t write this post without including some sort of proof that it actually works. :)

Lasers! They’re awesome!

19 replies on “Laser Kaleidoscope”

The best thing about 3D printing them was that I didn’t need to introduce anything to make them non-precision, it just sort of happened. I probably printed more than 6 mirror mounts and ended up selecting the 3 that worked the best.

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Hi Pete, I’m trying my best to imagine the whole thing working and what I can’t figure out from what you describe and by looking at the photos is how are the mirrors arranged. I understand it can work with one, two or the three mirrors rotating but I can’t figure out the placement. Could you make a quick sketch that just outlines the path the laser follows through the mirror setup?

Hey, regarding how you mounted the mirrors… did you mount them onto a flat and perpendicular surface that attaches to the motor shaft, or is there any angle to them? I think I’m way overdoing it on having an angle , and by the time the beam gets to the third laser, the “spray pattern” is so big that it’s missing it most of the time. I’m probably answering my own question.

Steve, Luckily my 3D printer is not precise, so a gentle angle is introduced by default. I printed maybe 7 mirror holders and picked the best ones (with angles) out of the bunch. Too much wobble will mean bigger mirrors, which is actually what I’d like to do when I upgrade this one…

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Ok. That’s pretty much how I would describe my 3d printer too, so I’ll undo what I’ve done to add the angle (puffy foam mounting tape) and see how it goes. Thanks! Seems like the smaller mirrors are ok for the first two legs of the trip, but by the time it gets to the third leg, things are getting crazy. My office is right down the street from a fabric/craft store, and I did see larger mirrors, so if I can’t get the light path to tighten up, a larger mirror should do the trick.

it lives! http://www.youtube.com/watch?v=B71f9m_MZGI&list=UUATIgSjWM4WXxYdM6nPoJjw&index=1&feature=plcp Mine is arduino driven for motor speeds via PWM pins. Although I did try dumping more voltage into the motors I found in a surplus store beyond the 5V that the PWM pins can output, and they ran a *lot* faster. So, I’m thinking about using transistors to let the arduino control a 12V power supply for the motors. i’ve never done that before, so that’s kind of why I want to do it. Not sure how it will affect the laser light show, but it doesn’t even matter. :)

Nicely made, especially the printed parts. One suggestion – add a circuit to pulse the laser and you’ll get a whole new range of patterns. A simple 555 based PWM circuit with variable frequency and duty cycle would work well.

Yes, excellent suggestion, I was just looking at some other projects in the similar vein on youtube, and pulsing the beam is on the todo list for tonight. I’ve also been really itching to do stuff with steppers, so I bought a couple Easy Drivers from sparkfun and have been messing around with them since it’s so easy that way, and then I saw that some of the higher end laser light show boxes use an XY stepper scanning technique… so I may go that a try too. I just picked up some TIP120 darlington transistors, so I’ll use them to let the arduino run the motors at 9-12 volts… should be cool!

Ultimately, I think I’m going to try to migrate all of the PWM over to a texas instruments TLC5940 chip, which is a 16 channel PWM controller. It takes 4 pins of input for 16 PWM out. pretty cool. I recently used one for another fun project and they’re surprisingly easy to interface with. If I can get all the code to fit, even minifying the project onto an ATTiny85 would be icing on the cake. MIT’s High-low tech group has what looks to be an excellent tutorial on that topic, so giving that a try is on my list after beam pulsing and adding the transistors.

We have two young kids, 4 and 1 years old, and I’ve been basically out of commission for most of the last year… my desire to make stuff has been building up this whole time. So, yay.

Noob here…any chance you could give a quick sketch of the wiring layout? Want to build one with my son and I’ve not soldered up potentiometers before or messed with “LASERS” before.
Thanks!

Hi Bill, yeah, I’ll try to work up a wiring diagram. It’s very simple though. The toggle switch is just on/off for the laser itself, wire to 2 AA batteries. For the 3 motors, they each have a button for on/off, and then the potentiometer are wired to each motor to control the speed. The 3 motors all run from the same 3 AA battery pack.

But if that’s confusing, I can see how a diagram might be more useful. :)

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This is really neat. Anyone know of any other resources/tutorials for relatively easy projects like this?

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