Loading
jasonwelsh

Stepper Driven Zoetrope

by jasonwelsh Apr 11, 2013
Download All Files

Thing Apps Enabled

Please Login to Comment

Isn't this actually a phenakistoscope?

Heh - that is a N size DC adapter Female end

What's the laser for?

How did you tell it where 0 was aka the first space between frame 12 and 1.
It's the starting factor and the timing that made the hall a good choice.

Hmm...perhaps I don't understand what you're saying (I don't see how a cyclical animation has a start frame, for one thing), but I suspect you're over-thinking the zoetrope. When using a stepper motor, you really don't need the sensors. (Alternately, using a sensor, you only need a simple motor).

I set up a basic example using the stuff cluttering my desk (arduino, adafruit motor shield, 400 step motor from a polargraph kit). I made a sketch that moves the motor 40 steps, then flashes an LED for a delay of 5. I stuck a ten frame animation on the motor. Here's what I got:

http://youtu.be/dD1hx6yLS9chttp://youtu.be/dD1hx6yLS9c (crappy video, it looks much better in person)

In addition to being simpler and more flexible (just a code alteration to change the frame count), this method is also more precise. On the other hand, for a big setup, holding torque would be a problem during the delay, so you might have to make a more complex sequence that wouldn't require a delay (setting the HIGH command a few steps early, and the LOW after four or five steps, say. This will introduce blur, but traditional zoetropes have that as well).

Anyway, I love zoetropes, stroboscopes, etc, and have been building them since the late '70's, so I hope your project helps spread the word and encourages more people to take the plunge. Now that I think of it, I got into 3D printing so I could populate my 'tropes, but I've been distracted by other projects.

Ya first Zoetrope here, never heard of it until I saw the Pixar one via youtube.. So the 3D frame is still good for the project, the code could be changed easy enough. I moved onto the next "Thing" though maybe later I'll revamp the code part after that. It will give adventure to the printed project interesting for others to try the coding.

I assumed that the slots let in light at just the right spots between frames to make the animation clear. So your saying that it can just flash so many frames per sec matching the frames of animation. I thought it had to flash at set spots just right between each frame hence the slots on the older tropes and the lines you see on my wheel. Interesting....

You defiantly have the time on your side..

Right, the only thing that matters is that the strobe frequency per revolution matches the frame count. If for some reason you really want the light to flash in an exact location relative to the animation, it should be made easy to move the light (or rotate the animation, if it's mounted on its own separate plate, which is a good idea anyway because one animation gets boring fast and you'll want to change them occasionally).

P.S. It's also good to be able to adjust the strobe frequency and the motor speed on the fly, because if you put abstract, regular patterns on your disc, surprisingly trippy effects will appear at different frequencies. Sometimes this simple technique gets better audience reaction than animations I've slaved over for weeks. Also, it's interactive, so people play with it for a while.

If the light is triggered by a hall sensor, why use a stepper motor? With a stepper couldn't you just flash the light every x steps? (I made a stepper driven 3D zoetrope many years ago, and I think that's what I did - I may be misremembering). e.g. - with a 1.8 (200 step) stepper, flash every 10 steps for a twenty frame animation.

LOL - +5 for the video! :) Awesome little project, and good use of the Tiny's!