It's not on the market yet but a Montana engineer hopes to make it big with a first-of-its-kind continuous compression 4 by 8-ft. square baler that he says outperforms plunger-type big square balers already on the market.

Built by Charles Siebenga, Belgrade, the baler uses a set of hydraulically controlled compression rollers to compress and extrude hay as it comes off transfer belts from a conventional hay pickup. The compressed hay feeds into a bale chamber that continually applies back pressure, provided by hydraulic cylinders, to the hay as it feeds in. When enough hay has entered the chamber to make a 4 by 8 bale, it's tied and ejected.

"The big advantage is that unlike conventional plunger-type big square balers that compress the entire bale at once, you're only compressing a small amount of hay at once. As a result the machine requires 30 to 40% less horsepower, weighs 30 to 40% less, and there are less complicated mechanisms to go wrong," says Siebenga, who figures the machine will cost only half as much as other big square balers while producing bales of the same density at the same or an increased rate.

The baler's continuous compression principle has been used in a baler built by Joseph Molitorisz as well as on an experimental baler built by Massey-Ferguson. Siebenga says he's taken the idea, which has yet to be a commercial success, and perfected it.

Key to success of the baler are the compression rollers mounted on hydraulic scissor hoists at the center of the baler. Controlled by micro-switches, they continually move up and down, feeding compressed hay in wafer-like layers to the bale chamber. The bale chamber applies back pressure to all four sides of the bale, controlled by a pressure reducing valve. The valve can be adjusted by hand to change the density of the bale for various baling conditions. Two hydraulic cylinders on opposite sides of the baler provide the pressure. Once the bale is formed, 6 standard Massey-Ferguson Suretie Knotters tie it off.

Siebenga, who originally began work on the new baler design for Vermeer Manufacturing, has produced one working prototype and would like to find a manufacturer. He's already had interest from several major manufacturers.