KUHN DMR 4855 disc ripper review

As machinery gets bigger and heavier, farmers are faced with the ongoing problem of soil compaction on their land.

To answer to growers’ demands for a deep ripper to help tackle this issue, KUHN released the DMR 4855 nine-shank disc ripper earlier this year at the KUHN expo at Cowra, NSW.

KUHN NSW territory manager, Gerard Cusack, recently showcased the DMR 4855 disc ripper machine to southern NSW growers at Griffith and Coleambally.

The 4.8m wide machine was pulled by a 470hp four-track John Deere 9470RXN at a depth of 16 inches (40cm) and a ground speed of six to 7km/h.

Boasting a narrow transport width, the DMR 4855-9 is 11m long and features five shanks at the front and four at the rear.

Excellent trash clearing

Cusack said the machine is capable of deep ripping to a depth of 400mm.

“It is a great trash clearing machine so is used for primary tillage straight after a row crop of cotton or corn where there is moisture and a lot of trash,” he said.

“We have done some demos around southern NSW and found it’s really good for incorporating trash and stubble after a crop for re-sowing or planting a cover crop.

“Residue is cut at the front and mixed through the middle and at the rear there is a set of off-set discs to finish residue mixing, breaking down clods to create a smooth, even finish.”

An innovative live hydraulic down pressure system allows the operator to set down pressure to match paddock conditions.

A split-the-middle shank pattern is achieved with two ranks of shanks on an 18-inch (45cm) spacing giving maximum soil fracture in heavy residue.

Blade depth is controlled with a crank-adjustable depth stop located at the front of the machine.

The disc conditioner system is hydraulically adjustable to meet varying surface residue – two rows of discs cut clods and provide additional levelling.

With an overall weight of 6.8 tonnes, the 4855 has a horsepower requirement of 400hp plus.

Boasting a heavy-duty 7-inch bar, the DMR 4855-9 will cultivate at a depth of eight inches (20cm) to 16 inches (40cm).

“The cutting coulters on the front are a standard 24-inch (61cm) straight disc on an 18-inch (46cm) spacing to size the trash,” Cusack said.

“The spring reset parabolic shank with a 7-inch (17cm) chromium point and a hard-tiled shin guard will rip down to 16 inches (40cm) deep.

“The shank does most of the work and has a reset of 1350kg at the tip.

“The parabolic shank grip the dirt and pull in so you get a nice, even pull across the whole machine and it will start a mixing process with the residue as it pulls in.

Reduce soil compaction

“As well as trash incorporation, the main point of these machines is to reduce soil compaction," Cusack added.

“The heavier harvesting machinery going into paddocks are placing pressure on the soils so the idea of this machine is to reduce compaction.”

The disc ripper is shod with four 360/65 R17.5 high flotation tyres mounted mid-frame designed to carry the whole machine evenly.

A second set of parabolic shanks are spaced to allow good trash flow and are followed by off-set discs and 24-inch diameter fluted coulters on a 12-inch spacing for residue incorporation and a level finish.

Attached at the rear is a soil conditioning roller which can be set on a spring tension or float position for wetter conditions.

“The conditioning reel spins quickly and works on spring-pressure for a consistent downforce,” Cusack explained.

“There are three reels across the width of the machine making it ideal for undulating country.”

Cusack said heavy trash loads were not an issue with the KUHN DMR 4855.

“This machine has come out of the US corn belt where the trash loads are high,” he said.

Minimum maintenance

Maintenance has been kept to a minimum on the KUHN DMR 4855-9. It is fitted with PEER TILLXTREME bearings in rock-protected, C-arm gang assemblies, eliminating the need for daily grease maintenance.

The bearing is protected by a six-lip seal to keep grease in and contaminants out.

A KUHN exclusive nylon ring surrounds the outer bearing race. The split ring design allows self-alignment reducing the chance of bearing preload.

An exclusive KUHN cast housing is designed to lock the protective nylon ring and prevent unwanted rotation around the outer race of the bearing.

The tractor interface centre prevents hydraulic hoses from binding in turns and includes a hose routing chart, colour coded hose grips, storage for light hook up and owner’s manual.

The DMR 4855-9 is available from KUHN dealers and in southern NSW from Hutcheon and Pearce.

The recommended retail price of the 4.1m machine is $100,585 excluding GST.

Specifications

Transport width: 4.2m

Transport height: 1.9m

Frame type: Rigid

Total number of shanks: 9

Shank spacing: 18 inch/46cm

Working width at shanks: 4.1m

Hitch: CAT IV articulating ball hitch with 2-inch pin hole

Depth control: Single point hydraulic depth control

Coulter blades: 25 inch

Blade spacing: 9 inch/23cm