3D printing is immensely technical and requires considerable knowledge. Here, Protolabs offers a handy guide on quality control in additive manufacturing.
What is additive manufacturing?
Additive Manufacturing also known as 3D printing, refers to creating three-dimensional objects by adding material layer by layer. As the name suggests, it is an additive process rather than a subtractive process such as CNC machining. Various additive manufacturing technologies exist, including stereolithography (SLA), direct metal laser sintering and Multi Jet fusion. Additive manufacturing offers flexibility, speed, and the ability to create complex geometries that might otherwise be challenging or impossible to achieve using traditional manufacturing methods.
Also read: Markforged Introduces Metal & Advanced Composite Industrial 3D Printer
Understanding key terms
Build Plate is the surface upon which the object is constructed.
CAD (Computer-Aided Design) refers to using computer technology to create, modify, analyse, or optimise designs for various purposes.
Deposition refers to the process of adding material layer by layer to build a three-dimensional object. This technique involves depositing successive layers of material to a digital design or model created using CAD software.
Extruder is the mechanism responsible for melting and depositing the filament material onto the build plate to create the object layer by layer—a critical component in deposition printing such as FDM (Fused Deposition Modelling).
Filament is the material used as the primary substance for creating parts (using deposition printing), fed into a 3D printer’s extruder. Filaments come in various types and compositions, such as ABS, PETG, TPU and Nylon.
G-Code is a set of instructions or commands in a standardised language that tells the (FDM) 3D printer how to create a part. A sequence of alphanumeric codes that control movement, speed, temperature and other necessary parameters to produce a 3D-printed part.
Heated Bed is a platform on which the object being printed is built layer by layer. The bed is heated to a specific temperature, which is usually between 50 to 100 degrees Celsius or higher, depending on the filament material used.
Infill is the internal structure of a printed part. Typically a pattern of lines, grids, or triangles. You can adjust the infill density, specifying how much of the interior space is filled with material. This is instead of printing a solid part, which would use more material and take longer, it also affects the weight of the part.
Jams are when the filament (material used for printing) gets stuck or blocked in the extruder, nozzle or another part of the 3D printer’s feeding system, disrupting the process.
Kapton Tape a heat-resistant adhesive tape, commonly used in (FDM) 3D printing. It’s a polyimide file tape that can withstand high temperatures, typically 200 to 300 degrees Celsius (or even higher in some cases).
Layer Height refers to the vertical thickness of each layer that makes up a printed object. When using 3D printing your part is built in a printer layer-by-layer. The layer height determines the thickness of each of these layers. So, if the layer height is set at 0.2mm, each layer of the printed part will be 0.2mm thick. The smaller the layer height the finer the detail.
Microstepping is a technique that is used to improve control and attain a smooth print. It breaks a single step into smaller steps, resulting in smaller increments of movement. Microstepping can be beneficial for several reasons, such as, smooth movement, and improved precision.
Nozzle is the part responsible for depositing and shaping the material used to create the layers that form the final part. The nozzle is typically made of brass (though occasionally other heat-resistant materials are used).
Overhang refers to material that extends beyond the previous layer without any support from the below. Essentially, it’s an area where the printer lays down material in mid-air. They can pose challenges because the molten material tends to droop or sag when printed in mid-air.
Print Bed Levelling ensures the build surface of the 3D printer is perfectly aligned and parallel to the nozzle/s. A level print bed is essential for adhesion and consistent layer height. If the bed is uneven or too far/too close to the nozzle, it can cause adhesion issues, leading to poor print quality or even failure to print.
Quality Control a series of processes and measures implemented to ensure that the printed objects meet certain standards, specifications and desired characteristics.
Raft refers to a supplemental structure printed underneath the actual part. It’s an additional layer or series of layers that serve as a foundation or support structure.
Slicer is software that converts a 3D model (typically in STL or OBJ file format) into instructions (G-code) that the 3D printer can understand and execute. It slices the 3D model into thin horizontal layers, generating a set of instructions for the printer on how to build each layer to create the final printed object.
Toolpath refers to the specific path that the print head (or extruder) follows while depositing material, creating each layer of the printed part.
UV Curing is a post-processing technique used predominantly in resin-based 3D printing processes like stereolithography. This process uses liquid photopolymer resin, which solidifies or cures when exposed to specific wavelengths of ultraviolet (UV)light.
Viscosity refers to the measure of a material’s resistance to flow. Depending on the 3D printing surface used "viscosity" can have a different affect. For example, fused deposition modelling (FDM) viscosity affects how smoothly the material flows through the printer’s extruder nozzle. Filament with a higher viscosity may struggle to flow, leading to clogging, which will lead to inconsistent flow.
Warping is deformation or lifting of the edges or corners of a printed part occuring during or after the part is printed. It occurs when areas of the printed part contract or lift away from the print bed, resulting in a warped or distorted final part shape. Several factors contribute towards warping, including temperature fluctuations, poor bed adhesion, printing on large flat surfaces, and high print temperatures.
The different axes
X-Axis Typically the horizontal axis that runs from left to right, perpendicular to the Y and Z axes.
Y-Axis Typically the horizontal axis that runs from the front to the back of the printer, perpendicular to both the X and Z axes.
Z-Axis Typically the vertical axis that runs up and down, perpendicular to the X and Y axes.
