Lubrication-free igus plain bearings ensure “quick and efficient” chopping in samo’s VarioCHOP system
Weed control without herbicides – for this purpose not only organic farmers, but also more conventional farms have relied on the chopping technology. For the quick, flexible and maintenance-free adjustment of machines, samo Maschinenbau developed their chopping device, the VarioCHOP. With it, the processing width can be adjusted directly from the tractor cab. This reduces time and weed control is more efficient. To enable the modern device to work reliably and maintenance-free, engineers rely on the lubrication-free polymer plain bearing technology from igus.
A look at Agritechnica 2019 shows that hoes and harrows are currently undergoing their renaissance. What only organic farming has been using so far has become increasingly important in conventional farms. Because, pesticides such as glyphosate are becoming increasingly controversial in weed control. In Austria, too, the chemical is already under discussion and a draft law on a glyphosate ban has been prepared. In order to successfully combat weeds, organic farmers in particular are currently relying on choppers that reach the roots of the weeds. The problem with conventional devices: they have to be set mechanically using the plate when stationary and at up to 60 points, using a spanner and foot rule. Operations that are very time consuming. For this reason, Klemens Ollmaier, Hannes Hutter and Philipp Holl from samo Maschinenbau developed the VarioCHOP system together with their project partner Roman Romstorfer. The name stands for the product range, because variable and infinite chopping modes are possible with the device. An invention that also delighted the DLG jury for the 2019 Agritechnica Awards and honoured the newcomers with a silver medal. The iglidur plain bearings from the motion plastics specialist igus ensure a safe and maintenance-free bearing for the movable chopping elements.
Agricultural engineering in the blood
Three young engineers from the field of agricultural technology are behind samo Maschinenbau. All grew up on Austrian farms and are intimately associated with agriculture. The passionate developers and designers came together and took over samo Maschinenbau in 2018, a classic contract manufacturer for machine tools.
Klemens Ollmainer, one of the three managing partners of samo Maschinenbau, said: “As self-employed individuals we have already developed many projects up to market maturity. However, we lacked direct production. Therefore, we decided to take over samo Maschinenbau in October 2018 and combine the two skills. Now we can develop new products in a dynamic team not only on paper, but also bring them to the end customer.”
Targeted and sustainable weed control directly on the plant
The farmer sows the seeds in spring. The chopping time then begins in mid-April and continues until July. The objective of chopping: get as close to the plant as possible to reduce weed pressure and reduce manual rework. Because, a chopped soil contributes to a higher water absorption by the plant and to an improved growth of the root. Depending on the crop, there are different row spacing and chopping intervals. While some fields only need to be chopped twice, other fields use the chopper up to five times. Since plants have a different size for each process and the soil has a different condition depending on the weather, the chopper must be reset each time.
Roman Romstorfer, organic farmer and project partner of VarioCHOP, explained: “For years we were annoyed by the tedious adjustment of the chopping elements, so we had to find a new and practical solution that would make life easier for the farmer and make chopping with centimetre accuracy, efficient and easy.”
No sooner said than done, the first prototype of the modern chopper which was created in 2017, is now ready for series production at the beginning of 2020, after several prototype stages.
Lubrication-free and maintenance-free bearing
The VarioCHOP consists of several chopping elements, the number of which the customer can determine themselves. Parallel kinematics make it easy to adjust the individual elements. Maintenance-free plain bearings were in demand here.
“We were looking for a material that was lubrication-free, robust and cost-effective, so we opted for the iglidur plain bearings from igus,” explained Ollmaier. A total of 18 iglidur plain bearings made from iglidur G tribo-polymer are used in the parallel kinematics of the chopping elements. As an all-rounder, iglidur G is wear-resistant, corrosion-free and light. By dispensing with fats and oils, no lubricants get into the soil. Another 14 plain bearings made of the same material ensure maintenance-free operation of the level guide.
Christoph Föttinger, managing director of plain bearing technology at igus Austria, added: “iglidur G has a high permissible surface pressure and is also very attractive in price as a large bushing with a diameter of 35 millimetres. Technically the best and the most cost-effective solution that works. Thanks to a large number of tests in the in-house igus laboratory, the material has also proven itself in heavy-duty applications for years.”
Fully automated chopping
The VarioCHOP system has a response time of five seconds and is conceivable for 2 to 99-row choppers. Simply mounted at the front and rear of the tractor, users can adjust the VarioCHOP chopping elements manually by hand with a cotter pin or, even more conveniently, directly from the tractor cab. The parallel kinematics of an element is driven by a precision hydraulic cylinder, which is coupled to a steering angle sensor. This means that the farmer can set the optimum processing width directly from the cab while driving. While in the past there was still a person sitting on the rear end of the tractor to monitor the correct position of the chopper, this function can now be carried out with a camera on the VarioCHOP. In this way, adjustment errors can be completely avoided and the width can be adjusted fully automatically. For farmers who chop different fields as service providers, the VarioCHOP enables enormous savings in time and cost. Furthermore, the user can save enormous herbicide costs with the chopper.
“We ourselves tested the VarioCHOP over several seasons and in several crops in our fields and are absolutely convinced by it, which is why we submitted our invention for the Agritechnica Award 2019,” said Romstorfer. The jury of the German Agriculture Society was immediately impressed by the concept and design of the new chopping machine. The VarioCHOP won the silver medal of the coveted prize and prevailed against a number of established agricultural machinery manufacturers.
“Our goal is to promote the VarioCHOP on the market internationally in 2020, because the device has great economic potential for farmers. With igus on board as a partner, we are able to do this, because the products are available directly from stock, are of high quality and at the same time are cost-effective,” Ollmaier concluded.
