Students build computer engine

You can almost see the light bulbs coming on in John Renner's class -- literally.

Renner, who teaches the OutlawNet computer class at Sisters High School, has introduced a Sterling Cycle engine to his students.

"We wanted to get the kids to do some engineering," he said.

Renner also teaches Social Studies, and that is part of his interest in this project as well.

"I also want to examine the social issues raised by an engine that has been pretty much ignored. The Sterling Cycle engine was originally sold commercially in 1895 as a water pump."

The model he demonstrated is solar generated, but he adds, "Sterlings can be powered by any heat source."

The Sterling Cycle engine that he demonstrated to his class consists of a tripod stand which mounts a parabolic dish. The dish has a mirrored surface with a front side reflector.

As the air is heated from the solar rays, a piston is driven down, which turns a fly wheel.

When attached to an alternator, the Sterling will have the capability of producing electricity.

"We got the design for this particular model from NASA," said Renner. "When we get this up and running, it will be a pretty cool deal."

His intent is to combine the best elements of responsible environmental concern with technological advancement. He plans to have his class design a working model that is four times larger than the one he demonstrated.

"Through a computer program, we can reverse engineer the Sterling Cycle engine, which will allow us to make a scaled-up model of it. We will then send it to a company in Bend, who will manufacture it for us," said Renner.

"We want to make it four times larger, so it will be powerful enough to run an alternator that will produce electricity.

"We will then be able to run a computer and a control system to keep the Sterling Cycle engine pointed at the sun," said Renner.