Reviews, Rock Picker

Review: Elho Scorpio stone picker

Mark Fouhy takes a closer look at the Elho Scorpio stone picker, designed and manufactured in Finland and distributed in Australia through Colac Ag.

While my personal experience with stone picking is (thankfully) limited, I did spend some time wandering the fields of Ireland while on an OE farming and contracting. This involved a tractor with a rock fork on the front, collecting rocks to prevent damage to cultivation, combine or forage harvesting equipment.

Land prices are only going one way, as there’s only so much land in the world and an ever-growing population. Producing enough to feed the masses is becoming more of a challenge.

Although flat land is the most desirable when it comes to growing crops and produce, there are different classes of flat land and potential uses.

Maximising available land isn’t always straightforward but one machine playing a key role in this is the Elho stone picker.

Built to withstand demanding conditions, the Elho stone picker helps effectively reclaim valuable acreage and create a clean and productive environment for farming operations.

Aside from crop yields, other benefits include less wear and tear on cultivation equipment and preventing damage to mowers and other harvesting equipment, as even with heavy rolling there will still be some rocks that don’t cooperate and like to cause trouble.

The end of the Scorpio’s unloading sequence. Source: Mark Fouhy


Ease of operation and precision engineering are two key reasons Elho Scorpio pickers are market leaders. Other pickers in the past have been PTO driven, resulting in extra maintenance, greasing, etc. However, Elho machines are fully hydraulic-driven, eliminating the need to worry about breaking shear bolts.

Utilising two hydraulic circuits, one at 110 bar and the second at 150 bar, the hydraulics automatically lift the picker if it does hit something too big or jams up. If it does happen to jam, there’s a hydraulic reverser function.

Full operation requires one single operating valve and another three double-acting valves to control all the functions of the picker.

Maximum working depth is up to seven centimetres, and depth adjustment is through the wheels mounted on each of the rotating picking wings. The main body of the machine has hydraulic ram adjustment on the drawbar.

At the outer point of each wing, there’s up to 700kg of lifting force to shift rocks from 25mm up to 400mm. The Hardox 500 used in the tines allows the machine to operate faster (125rpm for tines) than traditional spring steel tines.

This higher rotation speed helps improve sieving and soil removal when picking and breaks up organic matter better.

The bars of the hopper are the limiting factor in terms of what size rocks you can collect. Screen bars that can be fitted include 30/40/100/110mm to suit various requirements.

The 1.8m diameter picker arms are bolted with rubber torsion bushes, used on a lot of cultivation equipment now, to help protect the arms from damage. The arms have weld-on tips for easy replacement when they get worn.

Repairs and maintenance can be carried out safely within the picker, with stoppers to prevent the bin from accidentally falling.

Central 1.8m diameter rock picking rotor operates at 80rpm. Source: Mark Fouhy

Although we had a McCormick X8 hooked up in front, this was a little bit of overkill in terms of the power required to run the Elho machine, as remarkably, it only needs 75 to 140kW and a hydraulic pump size of 110 litres per minute as a minimum.

With a maximum hydraulic flow rate required of 85 litres per minute, flow rate was turned way down on the tractor.

The benefit of the larger tractor comes in pulling a full hopper load of rock, which can be between 1.5 to 2 cubic metres, depending upon the size of rocks picked.

The tandem axle running on a bogie system with 560/60R 22.5 tyres handles the weight of the 6.8-tonne empty machine and the loaded machine, preventing it from sinking into the paddock or making it unnecessarily hard to pull.

Once fully loaded, the rocks will start being flicked back out of the hopper. Once the picker has stopped, you can back up to a trailer or truck to dump the hopper load of rocks.

With a maximum dumping height of 2.7 metres, I’d estimate the process would take between one to two minutes, so depending on the paddock, you may need a trailer or two to keep up.

Automatic depth adjustment enables the machine to follow the surface of the ground with constant working pressure. This makes it easy to operate the machine even in extremely dusty conditions.

Working conditions

The conditions you’re operating in will determine how fast you cover the ground. Forward speed can be anywhere from one to seven kilometres per hour (on our test day we were picking at around 1.5km/hour). Soil conditions are also a factor.

Ideal conditions are either a frosty morning or hot and dry, allowing rocks to be collected with the least amount of soil.

The other factor is, of course, the number of rocks on the paddock and the size of them. Larger rocks will fill up the collection hopper faster and a greater quantity of rocks will fill the hopper quicker than a less rocky paddock, requiring more time spent unloading.

Rock hopper filling up. Source: Mark Fouhy

Elho models

The original Elho Scorpio 550 is currently available in Australia, which gives a working width of 5.5 metres. Since then, Elho has added both larger (710) and smaller (430) versions to suit bigger and smaller operations/contractors.

The Scorpio 550 also comes in a second model, the SF (side flow), which uses a conveyor system to continuously unload into a trailer on the move. This may be more efficient time-wise in some situations.


My thoughts on stone picking are that it’s a hard, dirty job that nobody loves doing. However, with the Elho Scorpio 550, the unwelcome task has been made easy. Extremely robust and well-built, with hydraulic drives, gives a reliable and efficient machine to get the job done. While like most machinery, it represents a sizeable investment (although not

in comparison to land prices), it would suit a large farm operation, a group of farmers, or as an additional service for a contractor.

Elho products are distributed in Australia through Colac Ag, and can be viewed at

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