Research On The Control System Of Binder-Jet 3D Printing Equipment Based On STM32

Binder-jet printing technology has the advantages of strong environmental adaptability,fast forming speed and low operating cost.In the forming equipment,the printhead,as the core component of the binder-jet 3D printing device,has a complex injection control mode and a high development cost of the control system.The existing commercial printing equipment has high precision and mature technology.Therefore,this topic makes full use of the advantages of commercial piezoelectric printheads,and a control system based on STM32 is developed for binder-jet forming 3D printing equipment.Based on the analysis of the overall structure of the 3D printing device,a scheme for the selection of the corresponding electronic control,temperature control and injection device are established.By performing analysis of the motion characteristics in the X,Y and Z directions,it is found that when the printhead device is stepped on the Y axis at a constant speed,starting and stopping vibration is large,which directly affects the forming quality of the printed sample.In this topic,to reduce the printing deviation caused by the vibration,we apply the trapezoidal curve acceleration and deceleration algorithm to realize the step control of the movement of the printhead device.The hardware circuit part of the control system takes the chip STM32F103VBT6 as the control core,and performs functional modular design on the hardware circuit,and then develops the underlying program for the corresponding function module.The printhead control module is composed of detection and feedback procedure to the encoder status,and a paper feed printing program;the motion module controls the step motion of the Y-axis printhead by a trapezoidal curve acceleration and deceleration algorithm,the Z-axis lifting and the powder-laying movement of the forming table;The temperature adjustment module measures the actual temperature through the detection program,and intelligently regulates the temperature of the binder by the PID temperature control algorithm.The system realizes the transmission of the information of the lower computer and the upper computer through the USART serial communication protocol.The binder-jet printing experiments shows that the control system based on STM32 runs stably,the powder is evenly leveled,and the printing speed is about 23 s per layer,which has certain efficiency.During the experiments,when the equipment is stepped at a constant speed,the forming error of the X-axis and Y-axis of the formed sample is within0.16 mm,and the forming error of the Z-axis is within 0.20 mm.However,when the motion system adopts the trapezoidal curve acceleration and deceleration algorithm,the forming error of the product in the X-axis and the Y-axis is within 0.14 mm,and the error of the Z-axis is within 0.16 mm,which reveals that the overall precision of the printing device is improved,and the expected effect is achieved.