With the gradual popularization of 3D printing technology, more and more ordinary users can be exposed to 3D printing technology and understand the charm of 3D printing. However, although the prospects are good, people have to worry about its printing accuracy. So, what factors will affect the printing accuracy of 3D printers? Today, Mohou.com will take fused deposition modeling technology as an example to discuss with you several factors that affect the accuracy of 3D printing products. We hope it will be helpful to all 3D printing enthusiasts.
Fused deposition modeling technology is currently the mainstream technology used by desktop 3D printers. Its working principle is to heat, melt, and extrude filamentary thermoplastic materials through a nozzle. Polymers such as ABS, PLA, and paraffin are used as the main materials. In fact, during the 3D printing process, many factors affect the accuracy of the finished product, such as the printer’s accuracy, printing temperature, printing speed, materials, etc. Let’s look at them one by one.
1. The accuracy of the printer itself
This point has already been decided at the beginning of purchasing a 3D printer, so be sure to make a clear selection before purchasing the printer. Next, the manufacturing and assembly accuracy of the 3D printer itself and the vibration during the working process will affect its printing accuracy. Unlike ordinary printers that can only move in the X and Y directions, 3D printers also add longitudinal movement in the Z axis in addition to minor deviations. For example, the XY plane error, the stiffness of the printer frame structure, and the materials used will have a great impact on its stability. For those professional users, choosing a heavier printing load and more metal materials will help the stability and durability of the printer.
In addition, the diameter of the nozzle also determines the width of the extruded filament, thereby affecting the fineness of the finished product. You must know that 3D printing constructs objects by printing layer by layer, so the layer thickness setting will also affect the roughness of the finished product. Use a large-diameter nozzle, and set the layer thickness to be thicker. Although the printing speed is faster, the finished product will be It is relatively rough; on the contrary, the printing speed is higher, but the finished product is more refined.
2. Printing temperature
The printing temperature we are talking about here actually includes the nozzle temperature and the molding chamber temperature. Among them, the nozzle temperature determines the material’s bonding performance, stacking performance, wire flow rate, and extruded wire width. Therefore, the nozzle temperature should neither be too low nor too high. If it is too low, the viscosity of the material will increase and the extrusion speed will slow down; if it is too high, the material will tend to be in a liquid state, the viscosity coefficient will become smaller and the fluidity will increase, and the extrusion will be too fast and it will not be possible to form accurately controllable filaments. Therefore, when setting the nozzle temperature, it should be selected within a certain range according to the properties of the selected wire to ensure that the extruded filament is in a molten and flowing state.
The temperature of the molding chamber will affect the thermal stress of the formed part. Although high temperatures will help reduce thermal stress, the surface of the part will easily wrinkle. If the temperature is too low, the quenching of the wire extruded from the nozzle will increase the thermal stress of the formed part. , which can easily cause warping and deformation of parts. To form smoothly, when printing ABS, it is generally better to keep the temperature of the forming room at 55 degrees Celsius, while for PLA, ventilation and heat dissipation must be maintained as much as possible, and heat preservation is not suitable.
3. Layer thickness and compensation amount
The so-called layer thickness refers to the layer thickness when slicing. Each layer has a certain thickness, which will produce step patterns visible to the naked eye on the surface of the formed product. The higher the layer thickness, the more obvious the texture will be, which will affect the size of the formed entity. error and surface roughness. For FDM technology, this is a principle error and cannot eliminate the step pattern, but it can be improved by setting a smaller layer thickness.
The compensation amount refers to the distance value between the actual processing contour lines of the finished part. For those models that require high accuracy, general modeling should try to provide compensation, especially for the inner hole. The setting and extrusion of the compensation amount It depends on the diameter of the filament and the performance of the 3D printer, so you have to explore it yourself.
4. Extrusion speed and filling speed
When the filling speed is reasonably matched, the greater the extrusion speed, the larger the cross-sectional width of the extruded filament. When the extrusion speed increases to a certain value, the extruded filament may adhere to the outer conical surface of the nozzle, causing scratches. The outer surface of the model affects its appearance. When the filling speed is faster than the extrusion speed, the material will be broken due to insufficient filling, making it difficult to form. On the contrary, when the filling speed is slower than the extrusion speed, the fuse will easily accumulate on the nozzle, resulting in uneven material distribution on the forming surface. Evenly, there will be lumps on the surface, which will affect the printing quality. Therefore, the filling speed and extrusion speed should be within a reasonable range.
If you want to produce exquisite 3D printing products, you need to have a comprehensive understanding of 3D printing technology and equipment. By mastering the various factors that affect 3D printing accuracy, you can better avoid failures, improve the cost-effectiveness of 3D printing, and achieve better economic value.