The focus of this paper is to develop a reliable method to predict 3D cutting forces during ball-end milling process. This paper uses the artificial neural networks (ANNs) approach to evolve an generalized model for prediction of cutting forces, based on a set of input cutting conditions. A set of ten input milling parameters that have a major impact on the cutting forces was chosen to represent the machining conditions. The training of the networks is performed with experimental machining data. This approach greatly reduces the time-consuming mathematical work normally required for obtaining the cutting force expressions. The estimation performance of the network is evaluated through a detailed simulation study. The accuracy of an analytical model, which is a feasible alternative to the network, is compared to that of the network. With similar system parameter estimates for both methods, the network is found to be considerably more accurate than the analytical model. The results of model validation experiments on machining Ck45 are also reported. Experimental results demonstrate that this method can accurately estimate feed cutting force within an error of 4%. The results also indicate that when the combination of sigmoidal and gaussian transfer function were applied, the prediction accuracy of neural network is as high as 98%.

The paper concerns the ecological aspects of liquid manure. In order to have a better insight into the efficiency of the machine, four samples of liquid manure were analysed, namely two samples from a pit without aerators and two samples from a pit with incorporated aerator. The analysis showed that the dry matter content in the liquid manure amounted to 5.05–5.74%. The sample taken from the pit with incorporated aerator after 20min of mixing contained the greatest quantity of the dry matter. The nitrogen and phosphorus contents were equal to the average; again the sample taken out of the pit with aerator stood out. The values of potassium exceeded the European average. The aerated liquid manure was spread on the surface more uniformly; it flowed off the plants and penetrated faster into the ground up to the roots. When the aerated liquid manure was sprinkled, the bad smell in the environment was considerately lower. Pumping into the cistern was much easier because it did not contain clods. The fodder remains were chopped and did not stop up the pipe. The cost of aeration was small in comparison with the devices for liquid manure mixing.

The efficiency of two feed-mixing trailers, differing in the manner of taking of feed and mixing of feed mixture, has been compared. Trioliet Triomix 1000 takes the silage fodder by cutting knives and mixes the feed mixture by a vertically placed worm. Kuhn Euromix III 850 F takes the silage fodder by a silage unloader and mixes the feed mixture by a large mixing worm placed at the bottom of the bunker. Trioliet is more efficient, since in addition to clean taking of the silage heap it is capable to load the bales, hay and other types of fodder. The mixing worm generates a well homogeneous fodder mixture and is easier to maintain. Kuhn is outstanding only in cutting and laying the fodder unto the manger.

In the contribution, a new hybrid optimization technique for complex optimization of cutting parameters is proposed. The developed approach is based on the maximum production rate criterion and incorporates 10 technological constraints. It describes the multi-objective technique of optimization of cutting conditions by means of the artificial neural network (ANN) and OPTIS routine by taking into consideration the technological, economic and organizational limitations. The analytical module OPTIS selects the optimum cutting conditions from commercial databases with respect to minimum machining costs. By selection of optimum cutting conditions, it is possible to reach a favourable ratio between the low machining costs and high productivity taking into account the given limitation of the cutting process. To reach higher precision of the predicted results, a hybrid optimization algorithm is developed and presented to ensure simple, fast and efficient optimization of all important turning parameters. Experimental results show that the proposed optimization algorithm for solving the nonlinear-constrained programming problems (NCP) is both effective and efficient, and can be integrated into an intelligent manufacturing system for solving complex machining optimization problems. To demonstrate the procedure and performance of the proposed approach, an illustrative example is discussed in detail.

The paper is concerned about the ecological aspects of liquid manure. In order to have a better insight into the efficiency of the machine, four sample of liquid manure were analysed, namely two samples from a pit without aerators and two samples from a pit with incorporated aerator. The analysis showed that the dry matter content in the liquid manure amounted to 5,05 - 5,74 %. The sample, taken from the pit with incorporated aerator after 20 minutes of mixing, contained the greatest quality of the dry matter. The nitrogen and phosphorus content is equal to the average; again the sample taken out of the pit with aerator stands out. The values of potassium exceeded the European average.

Rolling is an activity of additional cultivation of soil. The rollers press the soil and the seed so that the latter sprouts faster, they crumble the soil, compact it and crush the clods. Different rollers were compared. During the field test the influence of rollers (Cambridge roller; toothed, rubber and smooth rollers) on the speed and uniformity of sprouting of the colza. The colza was sown on 12 September, 2001. The number of plants was counted on 21 September, 2001; 24 September, 2001; 27 September, 2001; 4 October, 2001 and 11 October, 2001. Throughout, the number of plants on the test area was the greatest in case of rubber roller (on 21 September, 2001 it was 105,80 and on 11 October, 2001 it was 137,60 plants on I in 2); the toothed, the Cambridge and the smooth roller followed. The average number of sprouting plants on 21 September was 103,55 and on 11 October 135,50 plants on 1 m(2). The number of plants was the lowest on non-rolled lots. Here the number of plants on 21 September, 2001 was 87,20 and on 11 October it was 129,80 plants on 1 m(2). The greatest difference in the number of plants from sprouting to the last counting of plants was on the non-rolled lots. It means that rolling had an impact on faster and more uniform sprouting.

The aim of crushing of waste materials is to reduce their volume and to use them favourably. For crushing small waste wood and branches into matchwood small tractor-driven machines and electric motor machines are used Larger machines for the biomass preparation are more capable and more expansive; they have their own drive and a motor output of more than 200 kW. The paper discusses testing of the new crushing machine TERMINA TOR 5000S - 181024 of Komptech make for different materials to be crushed The test includes crushing of different types of materials of different densities by means of new crushing rolls.

Technically correct spaced sowing is a prerequifite for successful growing of crops. Spaced sowing must provide optimum conditions for the growth and development of plants.Thorough knowledge of biotechnical characteristics of the seed is necessary for successful sowing, such as: seed mass, floating, germinativeness and cleanness.The contribution presents. sowing machines for spaced sowing, their component, parts and mode of working. According to the mode of working we distinguish the following types of sowing machines: mechanical, pneumatic under pressure and pneumatic under vacuum.In Slovenia we compared two types of sowing machines for spaced sowing of corn. We focussed our attention on the influence of the speed of spaced sowing oil the depth of sowing, row spacing and seed spacing.

The paper demonstrates how different levels of shaft revolutions affect the performance of spinning single-disc and oscillating spout fertilizer spreaders widely used by Slovenian farmers. Tests have been conducted on a spinning single-disc spreader manufactured by the Italian company AGREX and on a oscillating spout fertilizer spreaders manufactured by the Slovenian company CREINA from Kranj. To establish the impact of different revolution levels on the transverse spread - dispersion, spread width and flow of a fertilizer, both types of fertilizer spreaders have been submitted to testing at different RPM levels of the tractor drive shaft: at 290 RPM, 410 RPM, and 540 RPM. It has been established that the different RPM levels have stronger impact on the oscillating spout spreader than on the spinning single-disc fertilizer spreader. The oscillating spout spreader performance at the rated speed has proved better than that of the spinning single-disc fertilizer spreader.

The contribution proposes an expert system for optimization of cutting parameters from commercial data bases. The expert system OPTIS serves for optimization of cutting conditions with respect to minimizing the manufacturing costs by taking into account the cutting process limitations. The programe is applicable only for turning. The OPTIS selects optimum cutting conditions with respect to the tool maker, workpiece material, type of machining, machine, smallest and greatest cutting conditions, tool, data on series, type of clamping and workpiece geometry. The paper presents the electronic catalogs for selection of tools and cutting conditions, their advantages and disadvantages.

AbstractThe use of rapeseed‐based lubricating oils has become more widespread in recent years. When these oils have been tested for their tribological properties, some imperfections have been found, especially in conditions of highfrequency and low‐amplitude oscillating movements. In the present work, we compare the tribological properties of commercially available rapeseed‐ and mineral‐based oils, rapeseed and mineral base oils, and these base oils mixed with two additives for improving lubricity. The results are compared for a wide range of contact pressures.