The rotary cultivator is making a small comeback for extremely shallow tillage applications. Italian company Sicma has its Bio Tiller for this top tickling operation, and we took a look at the 5.20m wide model last season … to see what it can do.
KEEPING IT BRIEF
- Is equipped with angled blades for particularly shallow work.
- Four pairs of pivoting gauge wheels help control the depth.
- Unfortunately, there is no UK importer for Sicma
Sicma, based in Miglianico, Italy, is one of the largest makers of tractor-mounted rotary cultivators. In fact, it markets about 32 different model ranges and versions in addition to covering the whole range of other cultivators. It not only builds the units, but also manufactures a good chunk of the components including driveshafts, gearboxes and cast elements.
Pivoting gauge wheels
The model we look at here is the firm’s RK Bio — a powered tiller for shallow operations.
Starting at the headstock, it has Cat III couplers that can be set to fixed or movable, depending on whether the tractor’s lower links allow the machine to adapt to the ground contours.
Guided by two pairs of wide, pivoting double gauge wheels, the machine’s working depth is set on lubricated cranks that adjust the gauge wheels. A laser-cut scale on each is a help here.
The lateral pivot on the wheels allows them to compensate for uneven ground such as ruts and provide more consistent depth control. This is important for ultra-shallow work, which is this machine’s main aim. The shape of the rotor blades, too, has been designed for shallow work, and these are fastened to the rotor to lift the soil at an angle of 93.5° even at their lowest point of contact.
In this way only the upper layer of soil and vegetation is removed, avoiding a compacted and smeared soil pan. However, the downside is that the shape of the blade results in a higher power requirement if you do want to do deeper work.
Sicma uses two rotors (with a diameter of 540mm), one left, one right, so it can fold for transport. A total of 120 x 8mm thick blades are mounted on the 127mm diameter rotors for an overall work width of 5.20m. Each blade is attached to the rotor with two bolts and stabilised with a double flange. The rear hood can be adjusted hydraulically or opened completely. A stainless steel or plastic lining is available as an option.
Separate driveline
As mentioned at the beginning, Sicma relies on its own components for the driveline. The driveshafts, for example, are supplied from sister firm, Eurocardan. Customers can choose between two types of overload protection — either the pto shaft to the tractor is protected by a cam clutch and shear pins in the two power-splitting shafts or vice versa.
Sicma doesn’t reduce the driveline speed at the central gearbox but out at the sides using the gearbox attached to the rotor. Here the speed is reduced from 1,000rpm to 420rpm via four cogs. Other rotor speeds are also available as an option.
As the gears are oil-immersed, the oil bath also lubricates the RK’s rotor bearings. The bearings in the centre of the machine are also oil-immersed.
Two narrow tines in front of the bearings cultivate the narrow strip in the middle of the machine. The bearings and gear drives are protected by replaceable wear skids.
Sicma also manufactures the frame of the RK520 in house. This has a double box plate with a curved base made out of S700 fine-grained steel. As well as providing some stiffness, this design prevents stones from damaging the paintwork.
For road travel, the two wings fold vertically to a total width of less than 2.50m. Robust warning panels are standard; Sicma intends to improve the lighting.
As for the price tag, Sicma’s list price for the 5.20m RK520 bio-tiller in test configuration is around £54,000.
Lucas Colsman
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