The tool-wear of cutting tools has a very strong impact on the product quality as well as efficiency of the machining processes. Despite the nowadays high automation level in machining industry, ...tool-wear diagnostic that is measured of the machine tool, still prevent complete automation of the entire machining process. Therefore, its in-line characterization is crucial. Thus, the paper presents developed innovative, robust and reliable direct measuring procedure for measuring spatial cutting tool-wear in-line, with the usage of laser profile sensor. The technique provides possibility for determination of 3D wear profiles, as advantage to currently used 2D subjective techniques (microscopes, etc.). The use of proposed measurement system removes the subjective manual inspection and minimizes the time used for wear measurement. In the manuscript the system is experimentally tested on a case study, with further in-depth performed analyses of spatial cutting tool-wear.
Nowadays polyurethane modelling foams are successfully replacing original materials in many applications due to certain comparative advantages also in copying artefacts. Milling is a fundamental ...machining operation frequently used in transforming products of PU foam. This experimental study focuses on surface roughness of milled PU foam. The influences of machining parameters on surface roughness in PU foam milling were assessed. Linear and area surface roughness evaluations after CNC milling are compared and estimated for the use in future research. Additionally the surface roughness values increase with a feed rate per tooth and decrease with an increase of spindle speed. The milling tests showed significant influence of modelling board density on the final surface roughness. Additional area surface roughness values have been evaluated.
Nowadays polyurethane modelling foams are successfully replacing original materials in many applications due to certain comparative advantages also in copying artefacts. Milling is a fundamental ...machining operation frequently used in transforming products of PU foam. This experimental study focuses on surface roughness of milled PU foam. The influences of machining parameters on surface roughness in PU foam milling were assessed. Linear and area surface roughness evaluations after CNC milling are compared and estimated for the use in future research. Additionally the surface roughness values increase with a feed rate per tooth and decrease with an increase of spindle speed. The milling tests showed significant influence of modelling board density on the final surface roughness. Additional area surface roughness values have been evaluated. Keywords: milling; polyurethane modelling foam; surface roughness U ovo doba poliuretanske pjene za modeliranje uspjesno zamjenjuju izvorne materijale u mnogim aplikacijama zbog odredenih komparativnih prednosti, tako i kod kopiranja artefakta. Glodanje je temeljna strojna operacija koja se cesto koristi u obradi proizvoda od PU pjene. Ova eksperimentalna studija usredotocuje se na povrsinsku hrapavost glodane PU pjene. Ocijenjeni su utjecaji parametara obrade na hrapavost povrsine u procesu glodanja PU pjene. Linearne i povrsinske procjene hrapavosti nakon CNC glodanja su usporedene i procijenjene za uporabu u buducim istrazivanjima. Isto tako vrijednosti hrapavosti povrsina povecavaju se s brzinom punjenja po zubu i smanjuju se s povecanjem brzine vretena. Testovi glodanja pokazali su znacajan utjecaj gustoce PU pjena za modeliranje na konacnu hrapavost povrsine. Dodatno su ocijenjene vrijednosti hrapavosti povrsina. Kljucne rijeci: glodanje; poliuretanska pjena za modeliranje; povrsinska hrapavost
Recent progress in robotics makes robots suitable for many different applications. Beside manipulative and installation applications, which are the most common for robot manipulator, milling can be ...performed as well. In the near future, robot manipulators, integrated with spindle, proper cutting tool and milling parameters could replace conventional CNC middle toleranced machining, especially for soft material end products. In general, tool life behaviour in milling with robots is not available or studied. Therefore, this work presents the analysis of HSS tool wear in milling MDF (medium density fibreboard) with an anthropomorphic robot. The focus is on the correlation of the tool wear and the workpiece position in the robot operation area. To analyse this, tests were performed in four different positions according to the distance between robot base and test milling position. Results show that increasing distance significantly affects tool wear, on account of vibrations, what shows completely different behaviour than stiff conventional CNC machine tools.Original Abstract: Najnoviji napredak u robotici cini robote pogodne za razlicite potrebe. Osim manipulativnih i instalacijskih aplikacija, koje su najcesce za robotske manipulatore, moze se obavljati i glodanje. U bliskoj buducnosti robotski manipulatori s integriranim vretenom, pravilnim reznim alatom i pravilno odabranima parametrima glodanja, mogli bi zamijeniti konvencionalne CNC strojeve kod srednjih tolerantnih strojnih obrada, pogotovo kod upotrebe mekanih materijala krajnjih proizvoda. U principu, trajanje alata i trosenje tijekom glodanja s robotima nije dostupno ili istrazivano. Stoga, ovaj rad predstavlja analizu HSS trosenja alata tijekom obrade MDF (ploce srednje gustoce) materijala s antropomorfnim robotom. Teziste je na meduodnosu trosenja alata i polozaja izratka u podrucju rada robota. Za tu analizu, ispitivanja su provedena u cetiri razlicita polozaja prema udaljenosti izmedu baze robota i ispitivanog polozaja glodanja. Rezultati pokazuju da porast udaljenosti znacajno utjece na trosenje alata, zbog vibracija, sto pokazuje sasvim drugacije ponasanje od krutih konvencionalnih CNC strojeva.
On account on nowadays trends in the field of finishing, hand polishing has to be replaced with superior process. An alternative is abrasive flow machining (AFM). In this paper, the influence of the ...process parameters and abrasive fluid flow on surface integrity, i.e. surface roughness and micro geometry, are investigated. The models correlating abrasive fluid flow and surface roughness are developed. To prove the efficiency, energy consumption analysis is performed comparing AFM and novel upgrade of it, i.e. AFM with movable rotatable mandrel. Results show that novel AFMmm is efficiently capable to remove WEDM (wire electric discharge machining) damaged surface, induce compressive residual stresses and produce polishing surface under dry conditions. Moreover, the novel upgrade of AFM process is besides finishing, capable also controlling the micro topography of the product.
The development of industry in the last ten years has caused the production of parts with relatively small dimensions. This has led to intensive development of efficient micro-technologies through ...research of processes, machines and tools. This paper presents the research of machinability, channels micro-milling in AISI D2 tool steel (X155CrVMo-5), hardened to 62 HRc. As the tool is used micro-milling cutter with diameter of 0.6 mm and relatively large working length of 5 mm. Analysis of surface roughness, burr on workpiece edges and reduction of cutter diameter due tool wear was performed.
This research investigates the relationship between innovation expenditure and its economic performance in 2,503 companies. The findings show higher innovation expenditure productivity in the group ...of Leaders; each euro invested in innovation yields EUR 13.90, but just EUR 7.70 in the group of Followers. ROE is 40% higher in Leaders. Recommendations are provided as to the improvement of business processes and results: financial investments in innovation should be increased in Followers, while simultaneously a substantial improvement in the efficiency of exploiting existing assets is essential. Companies should increase their expenditure on extramural RandD, acquisition of external knowledge (concept of open innovation model) and market introduction of innovations. Further on, we compared some financial data on Slovenian companies with EU average data. The results clearly indicate that Slovenian innovation expenditures are relatively high but not being applied optimally to achieve economic results that compare to the EU average. Reprinted with permission of the journal Innovation: Management, Policy & Practice (ISSN 1447-9338) - www.e-contentmanagement.com
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