Factors affecting 3D printing accuracy
3D printing is one of the most popular and vital technologies in the field of Rapid prototyping. Ordinary printers can only achieve movement in the X and Y directions, while 3D printing adds longitudinal movement in the Z axis and utilizes 3D CAD data models to stack materials layer by layer into entities that match the shape of the model. This greatly improves the ability to manufacture complex parts, shortens the development cycle of new products, and reduces research and development costs.
The cumulative technology used in 3D printing is complex and diverse, and the corresponding printing materials are also diverse. Fused deposition modeling technology (FDM) is to extrude thermoplastic filamentous materials through heated nozzles. This 3D printing technology does not need laser, and the equipment used is low in cost, the process is brief, and there are many kinds of available materials. It is mainly polymer such as ABS PLA and paraffin, which is relatively cheap and has high utilization rate. It is the mainstream technology used by the current popular desktop 3D printers.
Let's take PLA material as an example to explore several major factors that affect product accuracy:
In the 3D printing process, there are many factors that affect product accuracy, such as the accuracy of the printer itself and the process parameter settings during the printing process.
1) Printer accuracy
The manufacturing and assembly accuracy of the printer itself, as well as the vibration during the working process, can affect its printing accuracy. For example, the XY plane error, the structure of the printer frame, and the stiffness of the materials used also have a significant impact on its stability. For professional users such as designers, having a heavier printing load and more metal materials contributes to the stability and durability of the equipment.
2) Process parameters
The printing temperature includes the extrusion head heating temperature and the hot bed temperature. The heating temperature of the extrusion head mainly affects the bonding and stacking performance of the material and the flowability of the wire. If the temperature is too low, it will make it difficult for the material to bond to the hot bed or cause interlayer delamination, and it is also easy to cause nozzle blockage; If it is too high, it will cause the material to extrude in a liquid state rather than a filamentous shape that is easy to control.
The nozzle temperature and hot bed temperature are important parameters that we need to observe and adjust in real-time during the printing process. Therefore, we need to choose a machine that can clearly display various parameters during the printing process. OME displays the temperature of the nozzle and platform in a curve, which has the advantage of being able to see the temperature changes over a period of time, thereby understanding the machine's condition at the moment before the error occurred. Not only that, the OME intelligent 3D printer also supports the status of consumable blockage, real-time monitoring of printing status, and achieving no material suspension printing and alarm.
(2) Nozzle diameter and layer thickness
The diameter of the nozzle determines the width of the extruded wire, which in turn affects the fineness of the finished product. Due to the fact that 3D printing materials are laid layer by layer, the setting of layer thickness also affects the roughness of the product. If a large diameter nozzle and a layer thickness setting are used, the printing speed is faster, but the finished product is relatively rough; On the contrary, the printing speed is slow, but the resulting product is more refined. When printing, it is necessary to comprehensively select the nozzle and set the layer thickness based on the model size and purpose.
(3) Printing speed
3D printing is a process where the printing speed and extrusion speed complement each other, and this requires a reasonable match to meet the printing requirements. If printing is much faster than extrusion, the material filling is insufficient, leading to wire breakage; On the contrary, it will cause the fuse to accumulate on the extrusion head, resulting in uneven material distribution. Due to the fact that the material used in the desktop printer is silk, it is only necessary to set the diameter and printing speed of the silk in the program, without setting the extrusion speed. The printing speed has a critical impact on the accuracy of the workpiece, and should not be too fast or too slow. It is necessary to set it in detail, including the printing speed of the contour, the filling speed of the solid, the printing speed of the supporting structure, etc. Generally, a slower speed should be set for the first layer to improve its finished product effect.
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