Joe Kline / The Bulletin Marcus Flores, 10, right, blows up his balloon car to test it as his brother, Cusi Flores, 12, watches during a STEAM Team event at the East Bend Library on Saturday. The monthly STEAM events involve activities based in science, technology, engineering, arts and math.

An activity at East Bend Public Library was a lesson in trial and error Saturday, as children built balloon-powered cars from empty plastic water bottles.

Chandra vanEighnsbergen, community librarian at the branch library, leads the monthly STEAM (science, technology, engineering, arts and math) Team projects for “tweens.” In the library’s meeting room, she described to the four children there how to create their homemade race cars. When finished, the cars would consist of an empty water bottle, plastic straw threaded through lengthwise with a blown-up balloon at one end, two straws for axles with wooden dowels inside and four cardboard circles for wheels.

“The wheels will be cardboard?” Marcus Flores, 10, of Bend, asked, questioning the integrity of the material.

VanEighnsbergen took a water bottle from Dexter Payne, 10, of Bend to help him make the first hole in the bottom where the straw with the balloon would go through. The plastic proved tougher than she expected.

As the librarian struggled to puncture a hole, Dexter and the other kids worked on taping balloons tightly to their straws with duct tape.

Kim Lazarski, of Bend, stepped in to help with her daughter, Meadow Lazarski’s, car. She was able to poke through a flimsier part of the plastic, and showed vanEighnsbergen what she had done.

“Why are you making a hole there?” Dexter asked vanEighnsbergen after she had started poking holes in the sides of the car.

“Because I need to make holes for the wheels still,” she said.

As vanEighnsbergen began snipping lengths of wooden dowel, Dexter cut wheels from cardboard circles. A little rough around the edges, the wheels didn’t look as if they would roll.

“What do I do now?” Dexter asked.

“We’ll use a hole punch to make a hole in the middle of the wheels,” vanEighnsbergen said.

She punched the first one, and Dexter completed the next three.

Once Dexter threaded all the straws on his car and added the wheels, he decided to try to see whether it would work, even though it was clear the axles were too crooked and the wheels a little too jagged to roll.

He inflated the balloon through the straw, pinched it with his fingers, set it on a clear tabletop and released his grip.

As the balloon deflated, nothing happened.

“Ah man!” Dexter said. He tried a couple more times but he realized a tuneup was needed.

Next, Meadow, 11, tried her car, but it wouldn’t budge either. Once she took off the wheels and inflated the balloon again, the car scooted on its dowels hover-board style, although not very far.

“Mine moved!” she said.

When Marcus was done, his car looked most like the example photo. The axles were straight, the wheels round, and the balloon set at an angle where it wouldn’t drag. When he let go of the balloon, his vehicle took off.

“Did it work?” vanEighnsbergen asked excitedly. She had been looking at Dexter’s car to help improve it, including trying to attach old CDs for wheels, which didn’t prove fruitful.

Marcus brought his car over for comparison. The decision was made for Dexter to cut new wheels and vanEighnsbergen to start on a new body.

“I’ll trace perfect,” Dexter said of the wheels.

After spending more time on it than the first, Dexter’s new car moved better. Marcus’ brother, Cusi Flores, 12, built a “boat” with his, so he needed to wait to test it at home (likely in the bathtub).

“OK let’s race!” Dexter said to Marcus. The two let their vehicles go on the floor, and Marcus’ won.

“Do you guys know what this project is based on?” vanEighnsbergen asked the children. “Newton’s third law: For every action, there is an equal and opposite reaction.” As the balloons released their air, the cars transitioned into motion — the opposite of remaining stationary.

By the time the builders were nearing the end, Dexter’s dad, Ben Payne, and Marcus and Cusi’s mom, Maria Flores, had returned to see how the project faired.

“It’s a wonderful experience,” Flores said, adding she brings her sons to many of the library’s monthly STEAM Team activities. “We do a lot of experiments at home with them.”

— Reporter: 541-383-0325,

kfisicaro@bendbulletin.com