Double-curved tine arms are designed to form fluffy and straight windrows for superior raking quality at higher speeds. Fluffy windrows allow more air movement through the crop promoting fast and uniform drying.

KUHN rotary rakes achieve this by following two basic principles for ideal windrow formation. First, the tine arms maintain a positive forward position right up to the point where the forage is delivered to the windrow ensuring gentle crop handling and minimal ash incorporation. Second, a steep cam track allows the tines to be raised very quickly to provide additional clearance over the windrow.

High-quality raking is only possible if the rotors are able to follow undulating terrain smoothly and closely without damaging the crop stubble. The GA 8131, 8731+ and 9531+ features 3D rotor articulation for excellent field adaptation. The rotor arm and rotor are connected by a double link rod which enables the 3D articulation, rotors follow ground contours efficiently to help you harvest a cleaner crop.​

Tine height adjustments are made on each rotor with a simple hand crank. Each rotor on the GA 8131 comes standard with a set of front fixed wheels with two fixed axles at the back. The GA 8731+ features a set of front caster wheels with two fixed axles at the back of the rotor to help follow changing ground contours to avoid tines from striking the ground. The GA 9531+ comes standard with a set of front caster wheels and a set of tandem axles in the rear, ideal for traveling over pivot tracks.

Both rotors can be quickly lifted with a single-acting hydraulic valve for lifting over obstacles and automatically locking the rotor lift during turns at field headlands to eliminate rotor swinging.

Easily adjust the working width hydraulically from the seat of the tractor.​ The working width can be adjusted from 23’4” to 26’3” (7.1 – 8.0 m) on the GA 8131, 25’3” to 28’2” (7.7 – 8.6 m) on the GA 8731+ and an adjustable working width from 27’6’’ to 30’6’’ (8.4 – 9.3 m) on the GA 9531+.

On the GA 8731+ and 9531+, the KGA 04C control box comes standard. The control box manages all the functions such as rotor working height adjustment, individual rotor lift (if machine is equipped with these options), rotor lift at headlands, working and windrow width adjustments. Simplified folding and unfolding between transportation and field working positions is also controlled from the control box for operator convenience. The KGA 01S control box is optional on the GA 8131.

The optional hydraulic rotor height adjustment equipment will require a 1 x DA, 1 x SA and an additional 3rd DA spool valve on the tractor on the GA 8731+ and 9531+. The GA 8131 requires 1 x DA and 1 x SA. The KGA 01S control box is also required for hydraulic rotor height adjustment.

The optional individual rotor lift feature allows operators to raise one of the rotors to avoid disturbing already formed windrows. This feature is especially helpful in wedge-shaped fields or when raking the final pass of crop into a windrow. The updated individual rotor lift design on the + models also helps reduce temporary weight transfer making the rake more stable.

The rotor suspension works in all situations; when rotors are in the lifted position, lowered position, or individually raised. KUHN recommends this optional feature for bumpy fields to help reduce stress on the structure, rotor arms, and rotor undercarriage. This option is also recommended with the individual lift feature.