Zoetrope/Fidget Spinner

thingiverse

This Fidget Spinner is also a variant design of the classic Zoetrope. A video of a few animations is available at https://youtu.be/fCx5waxvbcg Construction The bearing is the 608ZZ skateboard bearing that is typical for spinners. It is tapped into place and the bearing caps are also. The weights can be your choice. The intent was to use (12) 1/4 dia x 1/4 inch length steel rod segments, but I found Neodymium magnets of the same size which are 2-1/2 times as heavy so only 6 of those are needed. They can be de-magnetized by heating. You can also use buckshot, 1/4 inch dia slingshot balls, lead split-shot weights etc and just epoxy them in place. Preparation The final printed animation image strip should have an overall aspect ratio of 9:1 with a height of 0.50 inches and a width of 4.50 inches. The image strip should be comprised of 12 images. The individual animation frames need to be compressed horizontally by 50% (see below). Most existing 12 frame animation strips that you find will have equal horizontal and vertical scaling and they will create Zoetrope images that are twice as wide as needed. An easy method of resizing animation strips for printing is to load them into a Microsoft Word document, click on the image and select size. Then change the width to 4.50 inches. The height will resize accordingly and hopefully be approximately 0.50 inches or a little less. The document should print with the animation strips at the proper size. The PDF file included will print correctly if printed to actual size (100%) on your printer. Function The classic Zoetrope is comprised of a cylinder with equal angular spaced slits, with a corresponding equal number of images on the inner surface opposite the slits on the inside of the cylinder. The slits move in the opposite direction of the images. This Zoetrope functions differently to accommodate the Fidget Spinner bearing. The slits are still on the outer cylinder equally angular spaced, but the images are on the center hub which is a cylinder one-half the diameter of the slit cylinder. This introduces a unique problem. Since the outer cylinder is moving at twice the velocity of the inner cylinder and in the same direction the animated image appears twice as wide while the height remains unaffected. To correct this the animation strip needs to be compressed in width by 50%. (This affect also appears to make the visible number of animated images on the hub reduce by half). The Tool The tool is included to make the assembly of the animation strips simpler. You can size and tape the animation and then remove it from the drum by pinching the sides together. The Shade The shade can be used to reduce the front surface reflections on the Zoetrope face in bright light. Miscellaneous Since the Zoetrope is so small and the animation is viewed at a distance through a tiny slit very little light makes it to the eye. An external light source like a flashlight will probably be needed to illuminate the images. Laminating the paper images you create with transparent tape will increase their life. I haven't been able to find any information about a Zoetrope of this design on the internet. This is possibly due to the effects listed above and if this Zoetrope wasn't also a Fidget Spinner I'm sure I would have done it differently too.