Introduction: Benham's Disk (See Color With Black and White?)
When I was a kid, I had a children's science book that had this picture. I could be a bit wrong on the exact design, but it was similar. This caught my attention, so I read what it was about. It said to cut it out (I just cut out a copy) and attach it to a spinner. It also said that when the circle spins, these black lines will look like they are colors! As it turns out, are not very vibrant and the effect is subjective. Some interesting things about this effect is that it seems to work differently for different people, and sometimes it will even work differently for the same person but at different times. And also, the colors each person sees can be different. In this Instructable, I'll be showing 2 designs that I have recently made for the spinners.
I made a video of this process, and if you would like to see that you can view it here: https://youtu.be/F0cyXrLlWDQ
Here are a few links that I found that describe this effect much better than I can:
https://michaelbach.de/ot/col-Benham/index.html
Supplies
Step 1: Making the Disk (for Both Spinner Designs)
I made this design using Inkscape. You can see that when I made the design, I put a little circle in the very center. I did this so that I would know exactly where to drill the center hole for the top.
After cutting out the design, I attached it to a thin piece of firm plastic using removable, double sided tape. I traced a line around the circle onto the plastic. I cut it out using a jigsaw. Another option would be to use an old CD.
Step 2: Getting the First Spinner to Spin
I used a 1/4" brad point bit to drill the center hole. This bolt is a 1" long 1/4"-20 bolt. To spin this as a top, I added a nut before the disk so that I had a place to grasp it to spin. I used 2 types of nuts on the back of the top. A nylon locking nut to hold things in place, and an acorn nut for the end of the bolt.
Step 3: Getting the Second Spinner to Spin
Let's go on to the other spinner design, I liked this one better. I took a washer with a 1/2" opening and cut it in half with my Dremel. Using my same plastic disk, I cut out notches from the center that the washer fits in snugly. I used a 1/2" ball bearing for the disk to spin on, but a marble would also work. Now I glue those parts in place with some epoxy.
After the epoxy sets, I tested it out. This works much better than using the nuts and bolt. I put some removable, double sided tape on the disk so that I can swap out designs easily.
Step 4: And That's It!!
Thanks for checking out my Instructable! If you try this out, please come back here and let me know if you see colors!
One last thing; Because this effect is caused by the design spinning, photos of the colors aren't possible (without image editing software.) So here are some short videos that I made with 3 designs, the one I made myself and 2 that I found online. If you see any colors on any of these designs, please leave a comment and tell me what colors you see.
Design 1: https://youtu.be/GHns4dmphUo
