You don’t need to wait for a carnival to satisfy your craving for cotton candy. Instead, build this portable, pocket-size machine to turn granulated sugar into an airy treat.
A DIY cotton-candy machine consists of a small metal container, repurposed lighter parts to provide heat, and a switch-controlled motor to set everything spinning. Slowly pour granulated sugar into the container, and flames from the lighters will melt it. As the motor spins, the liquid sugar will fly out through little holes in the container’s sides, forming thin strands. A paper cylinder placed around the machine will capture them. Once they’ve built up, simply swirl a chopstick around the perimeter to gather the candy and taste your sweet success.
This article originally appeared in the September 2015 issue of Popular Science, under the title "Build Your Own Cotton-Candy Machine."
- Time: 2 hours
- Cost: $26
- Difficulty: Medium
- Push pin
- Power drill
- Soldering iron
- Long-nosed lighter
- Torch lighter
- Two-part epoxy
- Metal stand-off with a screw, washer, and nuts
- A small cosmetic aluminum container (found in drugstores) or a metal drink cap
- Small project box
- DC motor
- AA-battery holder
- Clay epoxy
- Paper, tape, rubber band, and a chopstick
- To build a system for heating the sugar, first open both lighters. Harvest the large fuel tank, igniter, and hose from the long-nosed lighter and the torch head from the torch lighter.
- Use the long fuel hose to connect the fuel tank to the torch head.
- For an ignition line, wrap a short length of wire around the metal base of the long- nosed lighter’s igniter and seal it with epoxy.
- Push the igniter’s new wire through the torch head— where the torch lighter’s wire previously was. This is the main ignition line.
- Connect the main ignition line to the brass part of the torch head. Seal with superglue.
- Next, set up the spinning chamber. Epoxy the metal standoff to the shaft of the motor. (When joining two parts together with epoxy, sanding both sides will yield a stronger bond.)
- With the push pin, punch holes all the way around the sides of the aluminum container, or drill tiny holes in the metal drink cap. Find the center of the container and drill through it. Add the screws, washers, and bolts to it, and screw it in place on the motor’s standoff.
- Solder the battery pack’s terminals to the motor. Since the screw tightens clockwise, make the motor spin counterclockwise to prevent it from unscrewing.
- To prepare the project box, plan where you will be placing the fuel valve, igniter, torch head, and spinning chamber. Mark each spot with a marker, and then drill the holes. You can use the photos as a guide.
- Epoxy the motor in place in the box. Glue the battery pack to the outer side of the box. Seal the igniter in place—the end should stick out of the box—with clay epoxy.
- Before sealing the torch system in place with the clay epoxy, measure the torch head and aim it at an angle so the flame will touch the near edge of the metal container.
- To operate the cotton-candy machine, tape paper into a cylinder that fits around it. Then switch on the motor, squeeze the fuel valve (and hold it in position with a rubber band), and spark the igniter. Let the machine heat for 10 seconds, then place the paper cylinder around it and slowly add the sugar. Collect the candy with a chopstick.
Warning: Take care handling lighters and fuel. The sugar is molten when it comes out, so keep your hands out of the way of hot flying sugar. Also keep hands and paper clear of the open flame—or you might end up making jerky instead of candy.