Make: Projects
CD/Suction Cup Status Dial
Just a CD, a suction cup, and a bit of foam makes a great status dial.
This project is derived from LifeHacker alum Jason Fitzpatrick’s improvised clean/dirty dishes indicator, which uses the same CD + suction cup idea.
When I tried Jason’s trick for myself, however, I found that, while the hole in an optical disc does fit nicely over the hub of a hardware-store suction cup, all the cups I could find had this molded-in groove to accommodate a wire hook. This groove prevents the CD from fitting snugly around the hub, and allows it to spin too freely. If you only have two states you want to indicate (e.g. clean or dirty dishes), it’s really not a problem. But if you want better resolution, the fit needs to be snug so the dial can’t “drift.”
So I’ve added a bit of craft foam that fits down in the groove and secures the CD in place, and doubles as a pointer. This design adds just enough friction: The CD is easy enough to turn, but not so easy that it won’t stay where you put it.
I’ve included a printable version of the label I made for my own “returning at” sign, which can accurately indicate 96 separate states (any 15 minute interval in the 24 hours of a day), but the design could easily be adapted to other purposes.
Steps
Step #1: Gather parts
Next
- You'll need:
- A junk CD, DVD, or CD-ROM
- A suction cup with a 15 mm hub grooved for a wire hook.
- About 2 square inches of craft foam with peel-and-stick backing.
- Remove the hook from the suction cup, as shown, and set it aside.
- If you want to skip the whole craft foam business, you can just bend the exposed end of the hook straight and slip it back on the suction cup once the CD is in place; it's a bit ugly, but works fine as a pointer.
