Stripper combine mounts on a tractor
"Stripper combining is the harvest system of the future for all small grains, including soybeans," says Cordell Lundahl, who's worked for years on a stripper combine that removes only the grain heads and pods from plants, leaving stalks standing in the field.
What makes Lundahl's stripper different from the new British stripper combine (see cover story) is that Lundahl's stripper head is a totally self-contained harvester that mounts on a tractor, unlike the British stripper head which mounts in place of a grain platform on a conventional combine.
Lundahl, who's best-known invention is the Hesston Stakhand, collaborated with Deere engineer Neil West to build his stripper combine. When Deere decided several years ago not to go ahead with commercial production of the head, rights to the invention reverted to Lundahl. "No one can believe how well it works. We can travel at speeds up to 14 mph and thrash 99% of the grain in the head. There's only about half the loss of a conventional combine and it cracks less than half as much grain. The machine is simple, with only a few moving parts, and it mounts on a tractor. We figure it could be built to sell for around $20,000, which is why it's not on the market. Companies have too much money tied up in full-size combines to switch to an inexpensive machine like this," Lundahl told FARM SHOW, noting that Deere has a new version of the stripper combine that it's still working on.
Lundahl's stripper combine is about the size of a grain head on a conventional combine. An up-front brush, fitted with heavy nylon bristles, bends the grain stalks backward into a row of round metal discs that strip heads off the stalks. The discs, spinning at 2,000 rpm's, throw the grain and chaff backwards into a rotating separator screen. The screen allows grain to fall into a feed-out auger and carries chaff, and bits of stripped-off straw, out onto the ground. If any grain heads remain unthreshed by the initial stripping action of the discs, they're threshed by a pair of feed-out brushes positioned where the feederhouse would normally be. All grain goes through the two closely mounted brushes on its way to a loadout auger, which carries it to a trailing wagon.
Critical to success of Lundahl's stripper combine is maintaining correct height so stalks feeds evenly into the stripper mechanism. To make it easy for the operator, Lundahl invented robotic header height controls. The controls worked so well, Lundahl licensed them to other manufacturers for use on their combines.
The Lundahl stripper separates about 97% of grain from the heads as it's stripped off the stalks, according to Lundahl, who notes that in a moist crop most of the hulls are left on the stalks so that from a distance it looks like the crop hasn't even been harvested. The rest of the grain is threshed as it's augered past separating screens on it's way to a load-out auger. All chaff is deposited back on the ground.
"It's an extremely efficient and inexpensive way to harvest grain. That's why we feel there's no question it's the system of the future," says Lundahl, noting that he's still negotiating with major manufacturers interested in the stripper harvester.
For more information, contact: FARM SHOW Followup, Cordell Lundahl, Lundahl International, 710 North Sixth West, P.O. Box 268, Logan, Utah 84321 (ph 801 753-4700).
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1987 - Volume #11, Issue #5|