Note that disco balls come in all sorts of sizes. If you’re hoping to fill a living or dining room with moving white dots, get a ball that’s about 12 in (30 cm) diameter. For a larger room, get a roughly 20 in (50 cm) disco ball.
Be sure to get a motor that can handle the size and weight of your ball. Some motors are designed for small disco balls, while others can handle larger ones.
Most disco ball motors will mount to the ceiling with screws. Keep in mind that there will also be a light aimed at the disco ball, so there must also be an appropriate space to hang a light that will point at the ball.
You can mount the spot lights in many different ways. If you get a spotlight specifically for this purpose, it may even attach to the disco ball’s base. It may also have a base of its own that you attach to the ceiling separately. The ideal distance between the mirrored ball and the spotlight depends on the size of the ball, as well as the size and strength of the light. Experiment with positioning the spotlight in different locations relative to the ball and mount it where it provides the desired effect.
You will likely need more cups than you think. Of course, this depends on the size of the ball you hope to make, as well as the size of the cups you use. Get about 100 cups just to make sure you have enough.
The specific numbers of cups you will use to complete this first circle is largely up to you. Keep in mind that you will be adding additional layers on top of this circle (with a few less cups each time) to complete a dome. If you’re using classic water-cooler sized styrofoam cups, use 16 cups to complete your first circle.
As you stack layers, the bottoms of each cup will tilt slightly more inwards towards the center of the dome that is slowly forming. It may be tricky to hold and glue the final few cups in the dome, so use clothespins to help hold the cups while you glue them in place. Make another dome in the same way. Together, these two hemispheres can be joined to complete the shell of your light.
Do the same for other side of the dome as well, then glue the two halves of the dome together with the rest of the LED bulbs balled up inside. If the LED string is powered by a plug, make sure to run the plug out between some of the cups.
Resale or thrift stores are a great place to get light fixtures. You can even remove many of the pieces of an old lamp so you just have a cord with a plug on one end and the bulb receptacle on the other.
If you have never wired a light fixture before, have someone who has help you out. Though it may seem intimidating, it’s safe and easy to do. Never work on the wiring of anything that is plugged in. Keep the plug out of the socket whenever you’re working on your disco light.
