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One of the additive manufacturing technologies alongside FFF, SLA/LCD/DLP and SLS is FGF, also known as Fused Granulate Fabrication. It consists in the fusion of pellets for injection molding, rotomolding, 3D printing filament production or even direct extrusion onto the printing surface with the help of a pellet extruder. The Mahor V4 pellet extruder is an excellent example of the latter since it allows 3D printing directly from pellets. This 3D printing method is slightly more affordable and no less versatile than filament 3D printing. The Mahor V4 pellet extruder can process plastics such as PLA, ABS, PET, PP, LDPE, HDPE, PBS and PCL. Materials like TPU, PC, PA, TPE, EVA, PVC, PS, POM, PBT and PVB are still being tested.
The Mahor V4 pellet extruder is a compact and light (190 mm x 86 mm x 42 mm, 750 g) but very powerful (Nema 17 bipolar stepper motor with a planetary reducer and a 5.18:1 ratio), redesigned to surpass its previous versions in terms of size and capabilities, and compatible with most FDM 3D printers on the market and DIY 3D printers. The Mahor V4 extruder is capable of depositing 200 g of plastic per hour, and achieving melting temperatures of 30-300 ºC and printing speeds of 60 mm/s. The printing head can travel at a maximum speed of 120 mm/s, with an acceleration of up to 500 mm/s2. There are 3 options available for the extruder: 12 V 50 W, 24 V 50 W, and 24 V 70 W. Before purchasing the V4 pellet extruder, the user should make sure to choose the right voltage.
Image 1: The hopper mount and the nozzle of the Mahor V4 pellet extruder. Source: Mahor XYZ.
The extruder is made of high quality materials (stainless steel fasteners, brass melting chamber, hardened steel screw, aluminum heat block, aluminum cover to protect from burns) and components, specially designed for the Mahor V4 extruder and manufactured with the help of various industrial technologies such as laser cutting and CNC machining.
The V4 pellet extruder has two fans responsible for cooling: a head axial fan and a centrifugal layer fan. In order to reach temperatures of around 300 ºC, it is recommended to regulate the head fan to half its power. This will reduce the cooling and help reach higher working temperatures in less time. The centrifugal layer fan uses automatic cooling based on the slicing software settings, in accordance with plastic type.
Image 2: The axial head fan (right) and the centrifugal layer fan (left) on the Mahor V4 pellet extruder. Source: Mahor XYZ.
Another interesting feature of the Mahor V4 pellet extruder is that the intensity of the extrusion flow can be modified by placing the heat block closer to or farther from the nozzle. Moving the heating block up will result in increased flow, and moving it down in decreased flow.
Image 3: Manipulating the flow by changing the heat block position. Source: Mahor XYZ.
With the Mahor V4 pellet extruder it is possible to 3D print just like with a normal 3D printer (even retraction is possible) but with a few additional benefits. Most importantly, the Mahor V4 extruder makes it possible to mix different colors and types of plastics by mixing base pellets with other material or color masterbatches in order to create customized materials. Furthermore, additivized plastic can be made by using additives according to the technical or decorative requirements of the design. For example, solid particles such as wood fibers can be added to the pellets under the condition that the maximum size of the fibers does not exceed the diameter of the nozzle mounted on the Mahor V4 extruder. Nevertheless, it is not recommended to introduce glass fibers, carbon fibers or other aggressive materials directly in the hopper as it can result in the excessive wear of the melt chamber. There are several possibilities for pellet feeding with the Mahor V4 pellet extruder: direct gravity feed, automatic pellet feeder or gravity hose.
Image 4: Pellet feeding methods. Source: Mahor XYZ.
Apart from ready made pellets, recycled plastic can be used with the Mahor V4 pellet extruder as raw material. The sources of the recycled plastic can be plastic bottles, 3D printing waste, removed supports, unused prototypes, etc. This feature makes the extruder a sustainable and affordable plastic extrusion device. A plastic shredder can be used to recycle the plastic and obtain usable shreds. In that scenario, it is absolutely necessary that all the shreds are uniform in size (1-4 mm in diameter pellets) in order to guarantee a consistent plastic flow. The size of the shreds can be measured with a caliper to ensure precision.
Image 5: The contents of the package. Source: Mahor XYZ.
The Mahor V4 pellet extruder comes almost completely assembled. Only some allen wrenches are required to install it on the 3D printer. The package contains the preassembled V4 pellet extruder, the resistor, the +400 ºC thermistor, some thermal paste, the fans, screws, some PLA pellets, and the product’s technical datasheet. There are no special software requirements, the V4 extruder will operate on the same slicing software the 3D printer uses (Slic3r, Cura, Simplify) with the same parameters as with conventional filament.
The great variety of the allowed material formats and plastic types allows for unlimited experimentation in the field of plastic extrusion and direct 3D printing with personalized materials. The compact size and low weight will not interfere with the operation of the 3D printer, and the open design facilitates the use of third party nozzles. Although the main objective of the Mahor V4 pellet extruder is direct printing, it is possible to make 1.75 mm filament with it. The only requirement would be to develop a cooling and winding system. The possibility to manufacture filament makes the Mahor V4 pellet extruder a truly versatile machine, with great potential to be modified and customized by the user to adapt to the project at hand and push the boundaries of additive manufacturing at an affordable price.
