Recycling system for the FDM/FFF method material designed for small and medium-sized production batches

With fast growing industry in the field of additive technology, possibilities of DIY (Do It Yourself) projects grow as well. This also gives the opportunity for non-expert's users to project and develop some complex products on their own. The reaction was global overflow of the 3D printer's sale worldwide. If we look in the long term, environmental pollution caused by their disposed polymer is their biggest flaw. Recycling process sometimes can be very expensive, and in certain cases unavailable for some users. In this paper, low-cost recycling system for materials that are most commonly used for FDM/FFF method is presented. The main goal was to reduce environmental pollution and 3D printing costs by presenting the possibility of making its own polymer made of scrape plastic. Moreover, this allows users to make their own recipe by mixing different types of scrape polymer, or adding reinforcing material such as chopped dry fiber, metal powder, etc.

Алати за обликовање лима - Практикум за моделирање делова и алата у програму Creo Parametric

Практикум је намењен студентима Mашинског факултета у Београду и садржи материју предвиђену наставним програмом предмета Алати за обликовање лима на првој години Мастер академских студија. Такође може користити и студентима који за Мастер рад одаберу тему из ове области. Додатно, Практикум је намењен и свима који желе да се упознају са принципима моделирања делова од лима, као и пројектовања алата за обраду делова од лима применом компјутера. Практична настава из предмета Алати за обликовање лима састоји се из лабораторијских вежбања где се студенти упознају са практичним решењима алата за обликовање лима, као и обрадним системима, и израдом пројекта алата за обликовање конкретног изратка из праксе. Практикумом су обухваћене припреме за израду пројектног задатка који се односи на конструисање алата за обраду лима за задати израдак. После обављених вежби, студенти су оспособљени да самосталним радом, уз предвиђене консултације, пројектују алат за обликовање лима и генеришу потребну излазну техничку документацију. Практикум је конципиран кроз седам вежби. Прве четири вежбе уводе студенте у начела моделирања делова од лима, а у петој врши се дефинисање положаја дела на траци лима и дефинишу операције обраде. У последње две вежбе, детаљно је описан поступак аутоматског пројектовања вишеоперацијских алата са редним извођењем. У вежбама су приказана упутства за коришћење софтвера PTC Creo Parametric 6. уз модул за пројектовање технологије обраде лима и конструисање алата Creo Progressive Die Extension (PDX) 12.0. У прилогу је дато упутство за инсталацију програма са лиценцом Машинског факултета и подешавање модула за пројектовање алата. Аутори користе ову прилику да се захвале рецензентима, проф. др Љубодрагу Тановићу и проф. др Младомиру Милутиновићу, на корисним саветима и сугестијама. Захваљујемо се и колегама из компаније CPS-CAD Professional Systems на пруженој подршци везаној за инсталацију, одржавање софтвера, материјалима за тренинг (обуку), као и за пружену помоћ око штампања овог практикума

Pregled stanja istrazivanja u domenu mikro-rezanja krtih materuala

Danas u domenu masinske obrade, mikro-rezanje predstavlja jednu od atraktivnijih tema istrazivanja. Ovaj rad predstavlja pregled stanja istrazivanja u ovoj oblasti, isticuci najuticajnije faktore, zbog kojih se mikro-rezanje u velikoj meri razlikuje od makro-rezanja. Tu spadaju: uticaj radijusa zaobljenja vrha alaia, negativni efektivni grudni ugao, kristalografska struktura materijala, itd. Kako je mikro rezanje moguce izvrsiti u rezimu plasticnog deformisanja, prikazani su mehanizmi, kojima se definise granica izmecu krtog i duktilnog fenomen

Recycling system for the FDM/FFF method material designed for small and medium-sized production batches

With fast growing industry in the field of additive technology, possibilities of DIY (Do It Yourself) projects grow as well. This also gives the opportunity for non-expert's users to project and develop some complex products on their own. The reaction was global overflow of the 3D printer's sale worldwide. If we look in the long term, environmental pollution caused by their disposed polymer is their biggest flaw. Recycling process sometimes can be very expensive, and in certain cases unavailable for some users. In this paper, low-cost recycling system for materials that are most commonly used for FDM/FFF method is presented. The main goal was to reduce environmental pollution and 3D printing costs by presenting the possibility of making its own polymer made of scrape plastic. Moreover, this allows users to make their own recipe by mixing different types of scrape polymer, or adding reinforcing material such as chopped dry fiber, metal powder, etc.

Contemporary approach to the design of circular form tools for complex-geometry part manufacture

Primena profilnih strugarskih noževa u industriji prisutna je unazad nekoliko decenija. Upotreba profilnih noževa u industriji je u ekspanziji, a ovu sve veću popularnost mogu pripisati smanjenju troškova proizvodnje i uštede vremena obrade. Sa druge strane, jedan od glavnih nedostataka predstavlja sam metod njihovog projektovanja. Ovaj nedostatak se ogleda kroz ograničenost obrade pravolinijskih i lučnih segmenata izratka. Grudni ugao za svaki segment ima različitu vrednost, što predstavlja dodatno ograničenje. U slučaju da je neophodna primena profilnih noževa za izradu delova složene geometrije, vrednost grudnog ugla zahtevala bi da bude nula. U ovom radu predstavljen je savremen način projektovanja kružnih profilnih noževa primenom CAD sistema. Na ovaj način, ne samo da se obezbeđuje konstantna vrednost grudnog ugla duž celog sečiva koja može biti i različita od nule, već se obezbeđuje i optimalna geometrija alata za obradu željenog materijala. Dodatno je izvršena i eksperimentalna provera geometrije profilnog noža projektovanog uz pomoć nove metode.Form tools have been used in industry for a number of decades. Their use is booming and such growing popularity can be attributed to minimized manufacturing costs and shorter manufacturing time. On the other side, one of the major drawbacks is the method of their design. It reflects in the constraints present in the machining of straight-line and circular arc segments of a workpiece. For each segment the rake angle has a different value, which imposes an additional constraint. In case it is necessary to use form tools to manufacture complex-geometry parts, the value of the rake angle would require to be zero. The paper presents contemporary design method of circular form tools by implementing CAD system. This way, it is not only provided a constant value of the rake angle across the entire cutting edge, which can be different from zero too, but also optimum tool geometry for machining a desired material. Additionally, the geometry of a form tool designed using a new method was experimentally tested

Experimental identification of the springback angle during the sheet metal processing of wider range of materials assisted with rapid tooling

The parts obtained by sheet metal forming technology can be classified as a percentage in the most common parts of assemblies and sub-mechanisms of mechanisms. The basic problem that occurs when making sheet metal parts using bending process, is the elastic return. The elastic return coefficient that can be used as a correction coefficient in the bending process is necessary to be determine for the used material, as well as for the processing conditions. All this led to high cost of the processing tool. On the other hand, rapid tooling constantly increasing its present in the processing presses. One of the biggest advantages of the rapid tooling is reduction of the cost and processing time of the final product. In this paper, the experimental identification of the elastic return coefficient for three different materials (Al-alloy, non-alloy steel and stainless steel) was performed, as well applicability of rapid tooling on sheet metal bending. The experiments covered a range of bending angles from 65° to 135°. It has been found that depending on the type of material and the bending angle, the elastic return coefficient can vary considerably. It also turned out that its value is significantly influenced by the geometry of the punch. All elements made using additive technology, successfully performed work tasks without the occurrence of destructio

Machining error determination for 3-axis milling of free form surfaces

The use of free form surfaces in mechanical engineering is accelerating by functional and esthetics demands. Use of CAD/CAM software is a must because analytical description of a given surface and tool path generation. There are many methods for tool path optimization, one of them is federate scheduling which is described in this paper. The machined part which is manufactured according to optimization algorithm was measured on the optical scanner. Paper presents description of developed CAD/CAM application in Matlabsoftware and performed experiment for determining the cutting forces in freeform surfaces machining. At the end of paper is given map of deviations determined by Matlab software for one of machined surface from point cloud obtained using optical scanner

Synergy of Nd:YAG Picosecond Pulsed Laser Irradiation and Electrochemical Anodization in the Formation of TiO2 Nanostructures for the Photocatalytic Degradation of Pesticide Carbofuran

This study proposes a simple and controlled method for producing TiO2 with phase junction, oxygen vacancies, and Ti3+ by combining picosecond pulsed laser irradiation and electrochemical anodization. Ti mesh was pretreated by irradiating with a picosecond pulsed laser technique using an Nd:YAG laser (1064 nm) at two fluencies, 15 J/cm2 and 30 J/cm2 . The samples were then subjected to electrochemical anodization to form TiO2 nanotube arrays on the previously laser-treated surface. This study will investigate the possibility of forming TiO2 nanotube arrays on a pre-laser-treated Ti substrate and determine their physicochemical and photocatalytic properties. The samples were characterized by FESEM, XRD, Raman, XPS, and UV-Vis DRS. UV-Vis spectroscopy was used to observe the progress of photocatalytic degradation for all samples, and degradation products were determined using GC-MS. With the synergistic effects of phase junction, oxygen vacancies, and Ti3+, the laser-treated TiO2 with 30 J/cm2 showed a higher photocatalytic degradation rate (85.1%) of the pesticide carbofuran compared to non-laser-treated TiO2 (54.8%), remaining stable during successive degradation cycles, which has promising practical applications

An overview of rapid prototyping technologies using subtractive, additive and formative processes

Ovaj rad opisuje metodologiju za primenu brze izrade prototipova primenom subtraktivnih, aditivnih i formativnih tehnologija na osnovu STL fajlova. Tehnologije brze izrade prototipova uključuju digitalni lanac informacija CAD/CAM /CNC, do nivoa koji omogućava uspešnu realizaciju fizičkih modela koristeći novu tehnologiju, dodavanjem, oduzimanjem i oblikovanjem materijala. U radu su razmatrane uobičajene tehnologije brze izrade prototipova, za koje je predložena generalizovana metodologija za njihovu primenu. Pokazane su i mogućnosti za verifikaciju programa pre same izrade modela. Metodologija je verifikovana na konkretnim primerima izrade izabranih delova koristeći tehnologije oduzimanja, dodavanja materijala sloj po sloj, i izrade kalupa (dodavanjem materijala) za livenje modela od silikona.This paper describes methodology for application of a rapid prototyping using subtractive, additive and formative technology based on STL files. Rapid prototyping technology includes using of a digital information chain CAD/CAM/CNC to a level which allows the successful realization of the physical models based on new technologies by adding, subtracting and molding material. The paper discusses about the usual technologies for rapid prototyping, for which a generalized methodology for their application has been proposed. The possibilities for program verification prior to the realization of the model were also shown. The methodology is verified on real examples of making selected parts. Used technologies are subtracting and adding material layers, layer by layer, and mold making (by adding material) for molding the silicone model

An overview of rapid prototyping technologies using subtractive, additive and formative processes

Ovaj rad opisuje metodologiju za primenu brze izrade prototipova primenom subtraktivnih, aditivnih i formativnih tehnologija na osnovu STL fajlova. Tehnologije brze izrade prototipova uključuju digitalni lanac informacija CAD/CAM /CNC, do nivoa koji omogućava uspešnu realizaciju fizičkih modela koristeći novu tehnologiju, dodavanjem, oduzimanjem i oblikovanjem materijala. U radu su razmatrane uobičajene tehnologije brze izrade prototipova, za koje je predložena generalizovana metodologija za njihovu primenu. Pokazane su i mogućnosti za verifikaciju programa pre same izrade modela. Metodologija je verifikovana na konkretnim primerima izrade izabranih delova koristeći tehnologije oduzimanja, dodavanja materijala sloj po sloj, i izrade kalupa (dodavanjem materijala) za livenje modela od silikona.This paper describes methodology for application of a rapid prototyping using subtractive, additive and formative technology based on STL files. Rapid prototyping technology includes using of a digital information chain CAD/CAM/CNC to a level which allows the successful realization of the physical models based on new technologies by adding, subtracting and molding material. The paper discusses about the usual technologies for rapid prototyping, for which a generalized methodology for their application has been proposed. The possibilities for program verification prior to the realization of the model were also shown. The methodology is verified on real examples of making selected parts. Used technologies are subtracting and adding material layers, layer by layer, and mold making (by adding material) for molding the silicone model