The new Lemken Rubin 12 compact disc harrow works soil up to eight inches deep at speeds up to 10 m.p.h. with 29 inch discs.
“Those 29 inch discs are the largest of any compact disc machine,” said Waldemar Heidebrecht, a Lemken distributor in Manitoba and Sask-atchewan.
“Maybe the old Wishak tandem disc was bigger, but for compact discs, our 29 inch diameter discs on the Rubin 12 are the biggest.”
The new machine is designed mainly for producers who grow corn on corn and need to do serious destruction to B.t. root balls and stalks.
Heidebrecht said the new Rubin 12, like the earlier Rubin 9, will also find a home with winter wheat growers.
“We have winter wheat growers who have been dealing with straw cover up to five inches deep with their Rubin 9,” he said.
“We say it’s good at 10 m.p.h. I have guys who go a lot faster. We don’t like to see that, but they do it anyway.”
He said the improved model 12 is unique in its ability to pull straight whether the front or back rows are set deeper. This is because of the symmetrical positioning of the concave discs, he added.
“Everybody’s compact disc machine sold today is designed so the front row of discs pull to the right hand side. The back row always pulls to the left hand side,” he said.
“That’s good as long as the machine is set level, but you often need more pressure front or rear. If you tilt the machine a little deeper at the front to be a little more aggressive, then the whole machine pulls off centre to the right. If you go deeper with the back row and put more pressure on the back, the machine will drift a little bit to the left. It’s difficult for the operator to get the machine all the time running straight.”
Heidebrecht said extra pressure front or back doesn’t affect the Rubin 12. The new symmetrical positioning of the concave discs prevents side-pulling, thus letting the Rubin 12 pull straight behind the tractor.
“The discs are divided in the centre. On the front row, some go left and an equal number go right. Same at the back. Equal numbers pull left and right,” he said.
“So the operator sets the front or the back as deep as he needs for the conditions, and the machine always pulls straight behind the tractor.”
Heidebrecht said the Rubin 12 has also eliminated the centre strip problem typically associated with old tandem disc machines.
“There was always that strip down the middle where there was no cultivation. Farmers never liked that,” he said.
“This compact disc is different. They designed special arms for those discs so the centre is always cultivated the same as the rest of the machine width.”
Many farmers are leery of deeper disc tillage, but Lemken product manager Ralf Bornemann, who supervised development of the Rubin 12, said it is necessary in B.t. corn.
“By going deeper, you can do a better job of mixing soil and residue than a shank cultivator while still operating at high working speeds of six to 10 m.p.h. for greater acreage performance,” he said.
According to Lemken, the new machine is intended to work deep to deliver intensive, uniform mixing and crumbling in one pass, even in heavy soil.
The company said this trait makes it an ideal primary tillage tool for corn growers in the fall.
The penetration depth and large disc diameter are also ideal for breaking pastureland, it added.
Lemken said convenience is critical in helping operators get the most work from their machine. The central hydraulic depth adjustment saves time because it lets the operator set the working depth of the discs from the cab. A self-locking device maintains consistent depth without manual spacers or pins.
The new machine allows multiple tillage functions in a single pass. An impact harrow behind the front row of discs is followed by a levelling harrow and depth guiding rollers to pack and level the soil.
Lemken said the big discs are individually mounted to the frame with pre-tensioned springs so they ride over stones. The double angular ball disc bearings require no manual adjustments or greasing. The cutting action and angle of the discs are expected to deliver better fuel efficiency.
Six Rubin 12 models will be available, according to a Lemken news release, with delivery beginning in July in widths from 10 to 20 feet.
Hitch options include mounted, semi-mounted and trailed versions. The semi-mounted version features a Uni-wheel, which mechanically lifts the roller and reduces the weight load on the rear tractor axle when the implement is raised for transport and manoeuvrability on headlands.
For more information, contact Heidebrecht at 204-712-7073 or visit www.lemken.com.