New tandem disc cultivator reflects demand

FARGO, N.D. – Many in agriculture assumed the tandem disc cultivator would become obsolete when farmers began eliminating tillage.

But last fall, Case introduced two new tandem disc cultivators because farmers needed to deal with tough residue on BT corn acres and rigorous tillage is one way to deal with that.

Case’s 370 model is a high-speed, primary tillage True Tandem machine that runs at eight mph. The 340 is a slower True Tandem finishing cultivator designed to run slower than six mph.

Case said its True Tandem design is built so the two blades meet in the middle.

The other basic tandem disc design is the double offset tandem, which Case said works fine on flat ground but can have problems dog tracking on the downhill side as the front blade follows the rear blade, said Rob Zemenchik, Case IH marketing manager for tillage products.

The surface may look smooth, but there are subtle, sub-surface irregularities that will make the planter unstable, causing erratic seed placement.

Zemenchik said it stayed with the True Tandem design for this new series because it creates a flat floor for the planter.

The 370 model can maintain a smooth, level finish at eight mph because the shallower concave fronts loft the soil in the air instead of having it corkscrew out the back end.

A good finish at higher speeds is possible because Case uses shallower concave cavity discs on the front gang.

With a shallower angle of attack and concave cavity, it penetrates better so operators can travel faster and cover more acres per hour, provided the tractor is large enough for the additional load.

The cultivators have hydraulic controls to keep the frame level fore and aft. On firm ground, the operator puts more pressure on the front to keep a level flow at the back. On mellow ground, when the front wants to go in, the operator puts more pressure at the back to level the output.

Zemenchik said the larger configurations of the Case True Tandem machines sport five sections, enabling the units to follow ground contours.

When the units debuted in Fargo, N.D. last fall, CNH representatives there said True Tandem cultivators don’t use ordinary discs. Compared to conventional blades under identical conditions, the shallow concave discs resist stress factures, are 30 percent stronger and last up to 20 percent longer. The special alloy is impregnated with boron for better wear resistance.

The implements have crimped centres, so they don’t distort or stretch where components bolt together. The parts cannot work into one another because it’s flat where the spool pushes against it.

The crimped centre also provides a formed bevel area beyond the spool. This shape chases the strength further out toward the edges of the blades, which reduces rock damage.

Both models feature flat case-nodular style spools with greater density for more clearance and better residue flow. Case said welded tubes and spools create a weaker gang. Tube-style gangs have less clearance, thus creating reduced residue flow.

Case said the blades resharpen as they wear.

Positions on the left side of the tongue perfectly match those on the other side of tongue, which lets the machine pull uniformly and in a straight line.

Blades in the rear will track directly between cuts from the front gangs, which Case said differs from other double offset designs, providing true, full-width cuts and leaving no uncut gaps.

The new True Tandem cultivator series will be available in 2010. List price for the 47 foot 370 is $109,000 US. True Tandem is available with a rigid frame or flex-wing unit.