CN103895229B - 3D print track control method, device and 3D print system - Google Patents

Abstract

The invention provides a 3D printing trajectory control method, device and 3D printing system. The 3D printing trajectory control method includes: obtaining a three-dimensional model of the model to be printed; calculating the slope of the outer surface contour of the three-dimensional model; setting a first rising increment along the slope direction; determining the vertical direction according to the first rising increment The second rising increment: controlling the movement track of the print head according to the second rising increment, so as to print. In the present invention, where the slopes are different at the bottom and the top of the model, the increment in the direction of the slope is fixed, so that the planned trajectory of the bottom position with a larger slope and the top position with a smaller slope is significantly different, that is, in the slope Smaller top print tracks are denser, allowing these special locations to be printed without supports.

Description

3D printing trajectory control method, device and 3D printing system

technical field

The invention relates to the field of 3D printing, in particular to a 3D printing trajectory control method, device and 3D printing system.

Background technique

The usual 3D printing method adopts a layer-by-layer stacking process method. The characteristic of the printing trajectory curve calculated by this method is that the height value of the same layer is a constant value, and when calculating layer by layer, the value superimposed upward is also a constant value. When using this method, when the slope of the model outline is small, it is necessary to increase the support structure. Increasing the support material will inevitably increase the material and printing time, and some support materials will also affect the surface quality of the model.

Fig. 1 shows a printing trajectory control method during 3D printing in the prior art. As shown in FIG. 1 , when printing a circular closed curved surface using the printing method of the prior art, each layer is divided into the same value ΔZ, and the printed model 1 is equally divided into countless curved surfaces 2 of equal height. In this way, at the position where the slope of the top of the circular printed model 1 is small, the lateral distances between adjacent layers 3 divided according to ΔZ are x1, x2, and x3 respectively, and the lateral distances increase rapidly as the slope decreases . When the value of the lateral spacing is greater than the diameter of the printing material, the layers cannot be bonded together, resulting in printing failure; or the support structure 4 is used below here, which causes waste of printing materials and printing time.

The current FDM (Fused Extrusion Deposition) 3D printing technology has problems such as slow printing speed, complex model support structures, and low efficiency. Some curved surfaces with large slope changes have poor printing accuracy or cannot be successfully printed. Promotion and development of technology.

Contents of the invention

The present invention provides a 3D printing trajectory control method, device and 3D printing system to solve the problems of slow printing speed, complex model supporting structures and low efficiency in the prior art.

As a first aspect of the present invention, a 3D printing trajectory control method is provided, including: obtaining a three-dimensional model of the model to be printed; calculating the slope of the outer surface contour of the three-dimensional model; setting a first rising increment along the direction of the slope; The second rising increment in the vertical direction is determined according to the first rising increment; the movement track of the printing head is controlled according to the second rising increment, so as to print.

Further, it also includes: calculating the height difference between the motion trajectories of the same layer; judging whether the height difference is greater than the first predetermined value; The height difference is limited within a predetermined range.

Further, the wire feeding adjustment strategy includes: adjusting the wire feeding amount proportionally according to the height difference.

Further, when the height difference is smaller than the first predetermined value, continue to control the movement track of the printing head according to the second rising increment.

As a second aspect of the present invention, a 3D printing trajectory control device is provided, including: a model acquisition module for acquiring a three-dimensional model of the model to be printed; a slope calculation module for calculating the slope of the outer surface contour of the three-dimensional model; The slope increment setting module is used to set the first rise increment along the slope direction; the vertical increment determination module is used to determine the second rise increment in the vertical direction according to the first rise increment; the first The control module is used to control the motion track of the print head according to the second rising increment, so as to print.

Further, it also includes: a height difference calculation module, which is used to calculate the height difference between the motion trajectories of the same layer; a judging module, which is used to judge whether the height difference is greater than the first predetermined value; a second control module, which is used when the height difference is greater than When the first predetermined value is reached, the motion trajectory is corrected through the wire feeding adjustment strategy, so that the height difference is limited within a predetermined range.

Further, it also includes: a calculation module for the amount of wire feeding, which is used to adjust the amount of wire feeding proportionally according to the height difference, so as to obtain a wire feeding adjustment strategy.

Further, it also includes: a second printing control module, configured to continue to control the movement trajectory of the printing head according to the second rising increment when the height difference is smaller than the first predetermined value.

As a third aspect of the present invention, a 3D printing system is provided, which is characterized by comprising the above-mentioned 3D printing trajectory control device.

In the present invention, where the slopes are different at the bottom and the top of the model, the increment in the direction of the slope is fixed, so that the planned trajectory of the bottom position with a larger slope and the top position with a smaller slope is significantly different, that is, in the slope Smaller top print tracks are denser so that these special locations can be printed without supports.

Description of drawings

Fig. 1 is the schematic diagram of printing track of existing method;

Fig. 2 is a schematic diagram of the printing track of the present invention;

Fig. 3 is a schematic diagram of the printing track when the height difference is generated between the same layer according to the present invention;

Fig. 4 is a control flow chart of the 3D printing trajectory control method of the present invention;

Fig. 5 is a schematic structural diagram of the 3D printing trajectory control device in the present invention.

detailed description

The invention discloses a 3D printing method based on the slope of the outer contour. This method mainly calculates the height value that needs to be raised for each layer of printing by judging the slope of the outer contour, and the trajectory curve required for each layer of printing. The trajectory of each layer may not be in the same height plane. The method of the invention can print complex curved surfaces without support, can make up for the defects of many support structures, slow printing speed, and low efficiency in the current printing process, and promote the application of 3D printing in a wider range of fields. In particular, the present invention is suitable for printing a single-layer or thin-layer model structure with a small slope without a support structure, which increases the application range of 3D printing technology and improves 3D printing efficiency.

As the first aspect of the present invention, please refer to Fig. 1 to Fig. 4, a 3D printing trajectory control method is provided, including:

The model acquisition step is to acquire the 3D model 1 of the model to be printed; in particular, the acquisition here may be obtained from outside, or the 3D model 1 may be constructed by itself.

The slope calculation step is to calculate the slope of the outer surface contour of the three-dimensional model 1 .

The slope increment setting step is to set the first rising increment ΔZ1 along the slope direction. In particular, the first rising increment ΔZ1 here may refer to the increment of the arc length along the outer surface. Among them, ΔZ1 can be determined according to the speed in the printing process and the diameter of the material used.

The vertical increment determining step is to determine the second ascending increment h in the vertical direction according to the first ascending increment ΔZ1. In this way, although the rising speed of the printing track on the same layer in the slope direction of the outer contour is a certain value (ie, the first rising increment ΔZ1), the value in the vertical height is different.

and the first control step, controlling the movement track of the print head according to the second rising increment h, so as to print.

Next, with reference to FIG. 2 , the above technical solution will be described as an example.

In the embodiment shown in FIG. 2 , the three-dimensional model 1 is a model with a regular outer contour. For example, the outer contour of the model has a centrosymmetric structure or a similar centrosymmetric structure, such as a common ball, cylinder and other shapes.

After the slope of the outer contour of the model is calculated by the method of the present invention, the first rising increment ΔZ1 along the slope direction can be set. In places where the slopes of the bottom and top of the model are different, the fixed value of the rise in the direction of the slope is ΔZ1, so that there is a significant difference in the planned trajectory between the bottom position with a larger slope and the top position with a smaller slope, that is, the slope Smaller top print tracks are denser, which has the benefit of being able to print these special locations without supports. In contrast, if using the prior art printing method shown in Figure 1, there would be a layer-to-layer disconnect at the top of the model, and only supports could be used or it would not be printed.

Due to the large difference in the slope of the outer contour of the 3D model, there will be a large difference in the height value of the same layer. To this end, preferably, it also includes: calculating the height difference between the motion trajectories of the same layer; judging whether the height difference is greater than the first predetermined value; when the height difference is greater than the first predetermined value, correcting the motion trajectory through the wire feeding adjustment strategy , so that the height difference is limited within a predetermined range. For example, the wire feeding adjustment strategy can adopt the strategy of reducing the amount of wire feeding or stopping the wire feeding, etc., to wait for the low profile surface to rise. Preferably, the wire feeding adjustment strategy includes: adjusting the wire feeding amount proportionally according to the height difference.

Preferably, when the height difference is smaller than the first predetermined value, continue to control the movement trajectory of the print head according to the second rising increment.

In the embodiment shown in FIG. 3, the three-dimensional model is not a model with regular outer contours. As shown in Figure 3, the slopes of the outer contours at the same height differ greatly, and the slopes of the n-layer and n+1-layer have certain differences. Then, the printing trajectory calculated according to the method based on the contour slope shown in FIG. 2 of this patent is as shown in FIG. 3 , and the trajectory of the same layer is not at the same height.

As shown in Figure 3, in this case, the slope of the outer contour will increase with the number of layers, and the height difference of the same layer will continue to accumulate. For example, when going to layer k and layer k+1, although the slopes are not much different, the height difference of the same layer is already greater than a certain value (namely the first predetermined value), and it is necessary to add a wire feeding adjustment strategy in the printing track.

For example, the wire feeding adjustment strategy may be, when the print head moves to a position where the height value of the same layer is larger, the amount of wire feeding is reduced or no wire feeding is calculated according to a certain ratio. In this way, the problem of excessive height difference of the same layer caused by the same layer printing in the later stage of printing will be adjusted to ensure the integrity of the final printed model.

As a second aspect of the present invention, please refer to FIG. 5 , which provides a 3D printing trajectory control device, which is used to implement the above-mentioned 3D printing trajectory control method. For example, the 3D printing trajectory control device can be realized by means of hardware, such as single-chip microcomputer, FPGA, embedded processor, digital circuit, analog circuit, digital-analog hybrid circuit, computer, PLC and so on. The principle of the 3D printing trajectory control device is the same or similar to the above-mentioned 3D printing trajectory control method, therefore, the same content will not be described here, please refer to the description in the 3D printing trajectory control method.

The 3D printing track control device includes: a model acquisition module, used to obtain the three-dimensional model of the model to be printed; a slope calculation module, used to calculate the slope of the outer surface contour of the three-dimensional model; a slope increment setting module, used to set the The first rising increment in the slope direction; the vertical increment determining module is used to determine the second rising increment in the vertical direction according to the first rising increment; the first control module is used to control according to the second rising increment The trajectory of the print head to print.

Preferably, it also includes: a height difference calculation module, which is used to calculate the height difference between the motion trajectories of the same layer; a judging module, which is used to judge whether the height difference is greater than a first predetermined value; a second control module, which is used when the height difference is greater than When the first predetermined value is reached, the motion trajectory is corrected through the wire feeding adjustment strategy, so that the height difference is limited within a predetermined range.

Preferably, it also includes: a calculation module for the amount of wire feeding, configured to adjust the amount of wire feeding proportionally according to the height difference, so as to obtain a wire feeding adjustment strategy.

Preferably, it further includes: a second printing control module, configured to continue to control the movement track of the printing head according to the second rising increment when the height difference is smaller than the first predetermined value.

As a third aspect of the present invention, a 3D printing system is provided, including the above-mentioned 3D printing trajectory control device.

The present invention is mainly aimed at the FDM 3D printing technology using engineering plastics such as ABS, and focuses on the model trajectory planning technology in the printing process. The invention optimizes and calculates the motion track of the printing head, and can realize fast and efficient printing of the model.

The present invention provides an effective method to solve the problems of low printing efficiency and many supporting conditions in the 3D printing process in the prior art. As long as the trajectory of the printed model is optimized and calculated, 3D printing can complete the fast printing of different models. Print. In order to save materials, regardless of stiffness, this printing method is more suitable for single-layer or thin-layer printing, which greatly improves printing speed and efficiency.

Claims (7)

1. a 3D print track control method, is characterized in that, comprising:

Obtain the threedimensional model of model to be printed;

Calculate the slope of the outer surface profile of described threedimensional model;

Set the first rising increment along described slope direction;

Determine the second rising increment at vertical direction according to described the first rising increment;

According to the movement locus of described the second rising increment control algorithm printhead, thereby print;

Difference in height described in calculating same layer between movement locus;

Judge whether described difference in height is greater than the first predetermined value;

In the time that described difference in height is greater than described the first predetermined value, by entering silk adjustment strategy, described movement locus is revised, so that described difference in height is limited in predetermined scope.

2. 3D print track control method according to claim 1, is characterized in that, described in enter silk and adjust a strategy and comprise: adjust in proportion into silk amount according to described difference in height.

3. 3D print track control method according to claim 1, is characterized in that, in the time that described difference in height is less than described the first predetermined value, continues according to the movement locus of printhead described in described the second rising increment control algorithm.

4. a 3D print track control device, is characterized in that, comprising:

Model acquisition module, for obtaining the threedimensional model of model to be printed;

Slope computing module, for calculating the slope of outer surface profile of described threedimensional model;

Slope delta setting module, for setting the first rising increment along described slope direction;

Vertically increment determination module, for determining the second rising increment at vertical direction according to described the first rising increment;

The first control module, for according to the movement locus of described the second rising increment control algorithm printhead, thereby prints;

Difference in height computing module, for calculating the difference in height between movement locus described in same layer;

Judge module, for judging whether described difference in height is greater than the first predetermined value;

The second control module, in the time that described difference in height is greater than described the first predetermined value, revises described movement locus by entering silk adjustment strategy, so that described difference in height is limited in predetermined scope.

5. 3D print track control device according to claim 4, is characterized in that, also comprises:

Enter silk amount computing module, for adjusting in proportion according to described difference in height into silk amount, adjust strategy thereby enter silk described in obtaining.

6. 3D print track control device according to claim 4, is characterized in that, also comprises:

The second printing control model, in the time that described difference in height is less than described the first predetermined value, continues according to the movement locus of printhead described in described the second rising increment control algorithm.

7. a 3D print system, is characterized in that, comprises the 3D print track control device described in any one in claim 4 to 6.