Make a Motorized LSD Spiral - a Powerful Illusion on Your Wall!

The "LSD Spiral" is one of the most powerful illusions I have ever encountered.  It's simply a spiral that reverses its directionality a few times.  When a spiral spins, it gives the impression of expansion or contraction depending on which way it's going.  Because of the reversals in the LSD Spiral, when spun it creates neighboring areas of opposing motion.  If you stare at its center for a while as it spins, you will 'get used to' the motion - the parts of your brain that respond to it slow their firing rate.  The result of this is quite impressive - when you look away, your brain will be biased towards the opposite direction of motion.  It's somewhat similar to color-based after-images, but higher-level.  You get a very noticeable bubbling and bulging of your surroundings, which is said to be similar to the effects of hallucinogenic drugs.

Being a neuroscience major, I'm fascinated by these sorts of things.  I decided to make a real-life motorized LSD spiral that I could hang on my wall and enjoy whenever I wanted to.  Here's what you'll need to make your own!

Materials:

• Large sheet of cardboard/thin plywood (I was lucky enough to have a big tv box)
• Acrylic paints (black and white are probably best, but I'm sure other colors would work too)
• Photo-editing software (mspaint is fine!)
• A printer
• A good knife or box cutter
• Some k'nex, including a motor
• Clear plastic tubing (optional but recommended)
• A drill and some scrap wood

I actually can't find the original video I used on youtube anymore, so instead I've uploaded the images I used to make my stencils onto imgur here.  You can download them and print them yourself.

Here's a video of it in action!

Stare at the center of the spiral until I move away from it. At that point, you can either look at your hand, some type, or anything else that doesn't usually bubble and shift crazily. The effect will only affect the part of your vision the spiral was in - so lean in close or make the video bigger (if possible) for a bigger effect.

Step 1: Prepare Your Circle

I got a new big screen tv, and used part of the huge box it came in for my spiral.  A thin sheet of plywood would be fine, but you're probably best off just finding a big box (maybe even a large pizza box?  That might be a bit weak, but it could do).

Decide how big you want your spiral to be.  Keep in mind that the effect it gives is limited to the space it actually occupies in your visual field.  The bigger it is, the larger the effect will be from any distance.

Cut out a circle (I used a string tacked to the center of the cardboard with a pencil tied to the end to mark it out) and paint it entirely white.

Step 2: Paint the Inner Spiral Arms

Now begins most time-consuming part of the process.  I looked around on youtube until I found a sufficiently powerful spiral design, and decided to recreate it.  I'm sure you could design your own spiral in photoshop or something, but I wanted a tried-and-true spiral.

I took a screenshot of the video, then printed out the part of it that contained one full inner arm.  I cut out the arm, and traced it onto a piece of stiff paper (I used some spam coupon).  I then carefully cut out the shape with my trusty knife.  The resulting stencil was stuck on the circle (I made sure to center it on that little hole made by the tack when I first drew it) and painted black.

It's crucial at this point to ensure that the arms will be equally spaced around the circle.  I took a straightedge and measured from the center hole to the very outer edge of the arm, then made a mark that far away from the center exactly opposite.  All I had to do was make sure that that dot was visible inside the stencil along with the center point, and I was set.

 Once I had two spirals opposite eachother, I measured 90 degrees away from the line connecting their farthest points, and made a third point the same distance from the center.  The fourth arm was made opposite that, and there you have it.  The first set of arms complete!

Step 3: Paint the Middle Spiral Arms

The next four arms are a bit tougher, but I used essentially the same method.  The video didn't show the entirety of an arm at any point, so I had to copy and rotate some bits around to produce an approximation of a full arm.  I then printed, cut, traced, cut, and ended up with a second stencil that was just larger than the first one.

The placement of the first of these arms is a little tricky, as it needs to be spot on but you can no longer easily use the center dot to help you.  I found the point exactly between the ends of two adjacent center arms, and made sure to start the arm there.  I also tried to position it so that it would be roughly one arm's thickness away from the beginning of the next arm by the time it got there.

Once you have the first arm done, you can use the same directly-across, ninety-degrees, directly-across method as you did for the first set.

Step 4: Paint the Outer Spiral Arms

This was the toughest part of the project.  Not only did I have no chance of getting a full picture of the outer arms, I also couldn't conceive of creating a stencil that large.  I ended up just doing them by hand.  I measured the remaining width of cardboard between the ends of the middle arms and the edge, and tried to draw them proportionally to the middle arms.  

I put a ruler along a radial, and measured the thickness and position of each middle arm that it crossed.  I then scaled these measurements and marked them 90 degrees away on the outer part of the circle.  Since the whole design is rotationally symmetrical, the same markings worked opposite and 90 degrees to either side of the first.  I then made similar measurements 90 degrees away from the first spot I measured, and translated those to between the first four sets of markings.  This resulted in 8 groups of markers which I could use to keep my arms on track as I drew them in.  I drew the curves in by hand and used a small paint brush to carefully outline and fill in the arms.

That's probably not the best way to go about it, but that's how I did it.  Below you can see the finished arms, and the edges of the k'nex system I rigged up that I'll explain later.

Step 5: Protect the Edges!

At this point in my project, I realized that the bare, slightly ragged cardboard edges were unsightly.  I found some plastic tubing, maybe 1 cm thick, and slit it all the way along its length.  I then bent it back away from the slit to pry it open, and let it snap shut again around the edge of my circle.  I then cut it to length and made sure it was on all the way around, resulting in a nice little edge protector.

Step 6: Motorize It

I cobbled together a cross of k'nex to hold the spiral securely in place, and attached that to a k'nex motor.  The rest of the assembly was just a makeshuft setup so that I could see how it looked spinning.  If you don't have any k'nex, any small motor would do fine, and I'm sure you could pull together a similar device out of wood or metal.

Step 7: Build a Mount for It

I actually left my spiral attached to something very similar to its original k'nex system for a couple of months, but eventually I decided to make a nicer mount to hold the motor and keep the whole thing upright.

I used a piece of scrap wood as the base, screwed the motor to it (taking advantage of the holes intended for k'nex to go through), and built a little support arch to ensure that the motor shaft wouldn't sag.  I slid the battery pack onto some nails towards the bottom, securing it with a rubber band so it could be removed and refilled.  This position also makes it accessible when the spiral is attached, as it controls the motor.  I used two more screws to keep the wire organized.  I first gathered up the wire and looped it, then pulled the whole bunch to the side with the battery pack attached to the base until it felt tight.  I marked two spots inside the loops and that's where I put the screws.  I also added a small spacer at the bottom to further encourage an upright posture and keep the battery pack from wanting to slide off.

Because of the innate bendyness of k'nex joints, I still had some problems with sagging at the joint between the shaft and the spiral sling.  I ended up epoxying those together, and that seems to have finally settled the issue.