November 10, 2000
Purdue fills need for school furniture in developing countries
WEST LAFAYETTE, Ind. By combining high-tech computer design and elements of traditional Shaker furniture, Purdue University wood scientists are filling a need for economical, functional school furniture in developing countries.
"Communities in developing countries have limited budgets for education," says Eva Haviarova, a graduate student working with Purdue wood scientist Carl Eckelman. "Once they provide a school building if they have enough money for that they feel they've done enough."
Since schools don't have money to buy furniture, Eckelman and Haviarova designed chairs and desks that can be made with low-tech equipment using local materials.
In three articles slated for publication next spring in the Forest Products Journal, the researchers describe the furniture designs they created to economically outfit classrooms. For their work, they'll receive the Woodworkers Helping Others award on Nov. 10 at the Midwest Industrial Woodworking Expo in Grand Rapids, Mich.
Stephen Terry, an Indiana high-school teacher who visited Eckelman's laboratory, was so impressed that he took the new designs to schools run by his father in Windsor, Jamaica. Together they hired a group of local carpenters and outfitted a school with new furniture.
"The school desks and chairs, Eckelman's design, are deeply appreciated by the entire community. One of the most positive factors was that the furniture was so inexpensive," says Jack Terry, supervisor of the Christ Community Churches of Jamaica Schools.
"The Jamaican carpenters who watched and assisted with this project were amazed at how quickly the desks and chairs could be assembled. All of our future schools will use this type of design."
Eckelman's furniture project started when Costa Rican officials asked for help after estimating they faced a shortage of about 100,000 school chairs and desks.
The chairs and tables had to be very sturdy, Eckelman says, to stand up to heavy use in the tropical climate. He estimates that most local furniture lasts only one to two years. Joints fail; plywood layers separate; lost screws cannot be replaced.
Where classrooms already had furniture, local teachers wanted new chairs and desks that looked like the old ones just built better. They could only afford a few new pieces at a time and didn't want students with new chairs to feel favored.
As the researchers looked for ways to improve existing designs, they saw that joint failure was a major reason for relegating chairs and desks to the scrap heap. The problem was the rectangular, mortise and tenon joint, in which a peg-like tenon fits in a hole called a mortise.
Traditionally, local craftsmen chopped rectangular holes for mortises in wooden uprights, then hewed the ends of side bars (called stretchers) into tenons to fit the holes. The fits were never exact, and joints pulled apart, or tenons broke.
That's when Eckelman took a tip from Shaker furniture makers: He decided to make round mortises and tenons just as Shakers had. But he still needed a way to standardize the pieces.
"We needed a design that worked without quality control because it's just not there," Eckelman says.
After studying Costa Rican resources, he designed a simple machine to manufacture a precise fit for each joint. Eckelman attached a deep hole saw to a simple electric motor and used that to drill tenons with exact, standard diameters. To create a matching, round mortise, he used a drill bit that fit on the same motor.
Eckelman drilled the mortise slightly smaller than the tenon, then dried the piece with the tenon until it fits into the mortise hole. When the tenon swells in the moist tropical air, it creates a tight joint. Glue makes the joint even stronger, but Eckelman says it isn't necessary.
The entire device cost about $50 U.S., Eckelman says.
Meanwhile, Haviarova used Eckelman's joint design as she sought out and created wooden test furniture from native Costa Rican wood species. She used computer-aided engineering software the same type used to design aircraft to determine the optimum size of the mortise and tenon and to design the strongest possible furniture using the most economical cuts of wood.
"The material we used was local," Haviarova says. "We made use of what would otherwise be waste material. We tested thinnings from timber plantations and unusable pieces from pallet decking. Local schools can get similar wood at reasonable prices."
Haviarova designed laminated wood, solid wood and bent wood furniture using simple equipment that is readily available in developing countries. Then she tested her designs using methods developed by the American Library Association, and her furniture designs and Eckelman's joints more than passed.
"Now we're working with the Institute of Technology in Costa Rica to test these in two schools," Eckelman says. "They'll build furniture locally and use it there."
Sources: Carl Eckelman, (765) 494-3640, email@example.com
Eva Haviarova, (765) 447-5811 firstname.lastname@example.org
Writer: Rebecca J. Goetz, (765) 494-0461, email@example.com
Other sources: Stephen Terry, (317) 594.5858 ext. 677, firstname.lastname@example.org
Jack Terry, email@example.com
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Purdue University wood scientist Carl Eckelman (right) and graduate student
Eva Haviarova are working on a project to provide cheap, sturdy school