Where I live, it’s officially leaf season, and they are everywhere. Driveways, sidewalks, and even blowing into my garage, where they stick to people’s feet as they come inside. Luckily, we have exhaustively tested all the major battery-powered leaf blowers on both fabric leaves and concrete blocks, and one model blew away the competition: the Ego Power+ 880 CFM, which delivered gaslike power while somehow also being the quietest. It even knocked over a 5-pound brick paver without having to engage turbo mode—the only one we tested that was able to do so.
Luckily, it’s on sale at Lowe’s this week, along with an extra backup battery so you never have to worry about running out of juice. It serves a practical purpose, to be sure, but there’s also a less practical purpose that WIRED contributing reviewer and leaf blower expert Sal Vaglica is happy to demonstrate.
Watch Sal show you how to turn the Ego leaf blower into a DIY toilet paper cannon—just in time for Halloween. (Sale ends November 4.) —Kat Merck
How to Build a Toilet Paper Cannon
With a few hardware-store parts—some you may already have at home—you can turn a battery-powered leaf blower into a toilet paper cannon that unrolls a single- or double-ply roll in seconds. Once assembled, you can use it to decorate a house or children. A blower’s airflow, usually measured in cubic feet per minute (cfm) and miles per hour (mph), helps power the effect. The fast-moving air creates a lower-pressure stream, while the still air around the roll pushes it toward that stream. As air follows the roll’s curve, it helps lift the roll, and friction carries the paper along. Bernoulli’s principle is part of the trick, along with curved-surface lift and the airflow pulling the paper forward.
To figure out where to position the toilet paper relative to the blower, I spoke with Saffron Wyse, associate principal at the international engineering firm Thornton Tomasetti, where she specializes in fluid dynamics. “Positioning the roll underneath the nozzle is slightly better because then you’re pulling the paper upward into the airstream, and you want it to go upward because that stream is going to do the bulk of the work for you,” she says.
All leaf blowers come with a tapered round tube, but some, including the Ego I used, also have a wide, flat attachment. The tapered round tube is the most stable solution, says Wyse, because it gives you a tall, wide airstream. But I’m building this for speed, which favors the flat attachment. “Having a thin nozzle arrangement that’s trying to flatten the airstream probably gives you more force, more velocity, so it’s likely to go further,” says Wyse. You could replicate such an attachment with duct tape and cardboard if your leaf blower didn’t come with one.
How to Build a Toilet Paper Cannon, step-by-step:
Start with a mini paint roller made for standard nap rollers. Avoid models designed for foam rollers, because they are too narrow. Slide a toilet paper roll onto the cage. If it fits loosely, wrap the cage first in painter’s tape, then in duct tape, adding layers until the roll grips securely. The painter’s tape ensures you’ll be able to use the roller for painting later on.
With the TP on the roller, position it beneath the leaf blower’s nozzle, about 3 to 4 inches from the tip and centered in the airstream. Use 12-inch strips of duct tape to secure the roller handle to the blower first, measure again, then add more tape to secure it. To help protect the nozzle from adhesive residue, apply painter’s tape to it before adding the duct tape.
Pull the first few sheets free from the roll, squeeze the trigger, and let the paper fly. —Sal Vaglica
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