"Under Head" Stubble Cutter Cuts And Windrows Straw As You Harvest

"Under Head" Stubble Cutter Cuts And Windrows Straw As You Harvest COMBINES Headers 25-6-11 California rice farmers are being restricted in the amount of rice straw they can burn, and new uses are being found for the straw. A team of researchers at the University of California-Davis set out a couple of years ago to find a more economical way to remove straw from the field. They came up with an "under head" cutter bar that will work in any grain crop. Since rice is harvested while fields are wet, the combine tends to mash the straw down into the wet soil, leaving it dirty and difficult to retrieve later, says Matt Yore, a UC-Davis engineering student and a member of the research team. They decided what they needed was a way to cut the straw stubble and clear it from the path of the combine before the combine runs over it. They designed an attachment that cuts and windrows straw as it's harvested. It consists of a sicklebar cutter with a draper windrower and fits under the header, just in front of the combine tracks. Hydraulic cylinders allow the cutting height of the cutterbar to be easily adjusted so it doesn't run in the dirt. The reseachers used a conventional combine header sicklebar with a wobble box drive. They designed a swing arm and connecting rod to connect the wobble box to the sicklebar, so the wobble box could be mounted just behind the cutter and not interfere with the header. A hydraulic motor and V-belt drives the wobble box. They also designed an easy-on attachment system so the operator can easily remove the stubble cutter when it is not needed. They designed low profile draper belts that can be positioned as close to the sickle bar as possible. Hydraulic motors also drive the draper belts. Because space under the header is limited, they weren't able to incorporate a reel or similar mechanism to push cut straw back onto the draper. The draper is designed with cleats that pull the straw once it falls on the belt. They added a variable displacement axial piston pump to power the sickle bar and draper drive motors, an auxiliary pump and directional control valve to control the lifting cylinders, pressure relief valves, filters, and a hydraulic fluid reservoir for both pumps. Controls were mounted in the cab to allow the operator to raise and lower the cutterbar and control the speed of the sicklebar and draper belts. While initial testing shows promise for the stubble cutting concept, Yore says there are a few problems that need to be worked out. Straw tends to build upon the draper so a more positive feeding method is needed. Yore says they tried replacing the sicklebar and drapers with a rotary disk cutterbar and initial results show better cutting performance, especially at high forward speeds. He says the research team will continue to evaluate both types of cutterbars and look for ways to improve the straw cutter to achieve higher straw yields without decreasing the field capacity of the combine. Contact: FARM SHOW Followup, Matt Yore or Bryan Jenkins, UC Davis û Biological and Agricultural Engineering Dept., One Shields Ave, Davis, Calif. 95616 (ph 530 752-1422); E-mail: mattyore@ucdavis.edu or bmjenkins@ ucdavis.edu.)

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