3 results listed
Large Scale Additive Manufacturing (LSAM) defines a system that can be used for printing
components on the order of several meters at high extrusion rates (up to 50 kg/hr). The feed stock
material is in the form of thermoplastic or fiber reinforced thermoplastic pellets which are almost 20
times cheaper than the filament based feedstock. The system has the potential to significantly affect
automobile, aerospace and energy industries. However, the design constraints of small-scale 3D
printing may not be applied to the large-scale printing due to the nature of the process. New design
rules and limitations should be taken into consideration. In this study, the maximum bridging distance
in large scale direct extrusion 3D printing system is investigated experimentally. A specially designed
V-shaped model is used for testing. The experiments were carried out for 2 mm, 4 mm and 6 mm
nozzle diameters under free- and forced-air cooling conditions. The failure of bead is determined in
terms of break off and sags down. The maximum bridge distance is dependent on the printer settings
(nozzle diameter, extrusion rate, travel speed, etc.), material, surface area-to-volume ratio of the
extruded bead and cooling rate (thermal effects).
International Congress on 3D Printing (Additive Manufacturing) Technologies and Digital Industry
3D-PTC2019
Ömer Eyercioğlu
Mehmet Aladağ
Adem Aksoy
Kursad Gov
Fused deposition modelling (FDM) is rapidly growing 3D-printing technology due to its ability of
building functional parts having diverse and complex geometries. However, printing materials are
limited to polylactic acid (PLA) or acrylonitrile butadiene styrene (ABS) in most FDM equipment.
Here, information about polycarbonate (PC) material, which is a high-performance printing material to
overcome these shortcomings, is provided. The mechanical properties of a built part depend on several
process parameters like layer thickness, air gap, build orientations, raster angle, raster width, fill
pattern and model building temperature. The aim of this study is to determine the effect of layer
thickness on the mechanical performance of PC samples manufactured with 3D printer. Samples with
three different layer thickness (178, 254 and 330 µm) were built using PC polymer material in the 3D-
printing system and their tensile and hardness tests were carried out. Results show that the tensile
strength (53.15 MPa) and hardness (57.9 HV) are highest in the samples with a layer thickness of 254
µm and 330 µm, respectively.
International Congress on 3D Printing (Additive Manufacturing) Technologies and Digital Industry
3D-PTC2019
Musa Yılmaz
Necip Fazıl Yılmaz
Ali Kılıç
Ömer Eyercioğlu
Shaped metal deposition (SMD) is a relatively new additive layered manufacturing method. It is a
novel technique to build net-shaped or near-net-shaped metal components in a layer-by-layer manner
via applying metal wire and selection of a heat source such as laser beam, electron beam, or electric
arc. SMD process is preferable as an alternative to traditional manufacturing methods especially for
complex featured and large scale solid parts manufacturing and it is particularly used for aerospace
structural components, manufacturing and repairing of dies/molds. TIG welding-based SMD method
is implemented by depositing continuous wire melted via heat. In this study, the overhang (self
supporting) angle in TIG welding-based shape metal deposition process is investigated. The overhang
angles are the angles at which a 3D printer can build tapered (overhang) surfaces without the need to
supporting material below the printing layer. The material, bead height, TIG weld parameters and the
environment temperature (cooling rate of printed layer) are the parameters which affect the overhang
angle. The results show that the maximum overhang angle is also dependent on the temperature of the
previous layer. For the selected set of process parameters, the maximum overhang angle is found as 28 , if
o
the temperature of the previous layer is cooled to 150 C before the subsequent layer is deposited.
International Congress on 3D Printing (Additive Manufacturing) Technologies and Digital Industry
3D-PTC2019
Ömer Eyercioğlu
Yusuf Atalay
Mehmet Aladağ
Oğuzhan Yılmaz