IN-FILLING FOR ADDITIVE MANUFACTURING

• US 20130313743A1
• Filed: 05/22/2012
• Published: 11/28/2013
• Est. Priority Date: 05/22/2012
• Status: Active Grant

• Current Assignee: MakerBot Industries, LLC (Ultimaker BV)
• Original Assignee: MakerBot Industries, LLC (Ultimaker BV)
• Inventors: Rockhold, Benjamin E.
• Granted Patent: US 9,463,598 B2
• Time in Patent Office: Days
• US Class Current: 264/40.1
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing

Abstract

Iterative techniques are disclosed for in-filling enclosed, interior volumes of three-dimensional shapes during an additive fabrication process.

Claims

1. A method comprising:

identifying a surface of a desired structure, the desired structure having an unspecified interior configuration;

enclosing the desired structure in a cell;

identifying an interior configuration by iteratively;

partitioning the cell into sub-cells;

discarding sub-cells that are entirely contained in an exterior of the structure; and

merging sub-cells that;

are entirely contained in an interior of the structure; and

satisfy a merging condition

until a stopping condition is satisfied; and

printing the structure with the identified interior configuration on a three-dimensional printer.

2. The method of claim 1, wherein the cell and sub-cells are cubical.

3. The method of claim 2, wherein partitioning cells includes partitioning a cube into eight mutually congruent cubes.

4. The method of claim 1, wherein the merging condition includes the condition that a given cell is adjacent to a specified number of other cells that are all contained in the interior of the structure.

5. The method of claim 4, wherein the specified number is seven.

6. The method of claim 1, wherein the merging the sub-cells is performed only in a specified direction.

7. The method of claim 6, wherein the specified direction is selected from the group consisting of horizontal and vertical.

8. The method of claim 1, wherein the cell and sub-cells are tetrahedral.

9. The method of claim 8, wherein partitioning includes barycentric subdivision.

10. The method of claim 1, wherein the stopping condition allows partitioning to be carried out to a maximum resolution of the three-dimensional printer.

11. The method of claim 1, wherein the stopping condition includes a constraint on at least one of a total required build material, a total required build time, a desired density of the structure, a minimum void volume, and a maximum void volume.

12. The method of claim 1, wherein the merging condition includes a constraint selected from the group consisting of:

a constraint on an overall mass of the structure, a constraint on a density of the structure, and a constraint on a location of a center of mass of the structure.

13. A system comprising:

three-dimensional printing hardware; and

control circuitry configured to operate the three-dimensional printing hardware to fabricate a three-dimensional object from a three-dimensional model that describes, at least in part, a desired structure, the control circuitry configured to process the three-dimensional object to in-fill one or more enclosed volumes of the desired structure by performing the steps of;

identifying a surface of the desired structure, the desired structure having an unspecified interior configuration;

enclosing the desired structure in a cell; and

identifying an interior configuration by iteratively performing the following steps until a stopping condition is satisfied;

partitioning the cell into sub-cells;

discarding sub-cells that are entirely contained in an exterior of the structure; and

merging sub-cells that are entirely contained in an interior of the structure and satisfy a merging condition.

14. The system of claim 13, wherein the cell and sub-cells are cubical.

15. The system of claim 14, wherein partitioning cells includes partitioning a cube into eight mutually congruent cubes.

16. The system of claim 13 wherein the merging condition includes the condition that a given cell is adjacent to a specified number of other cells that are all contained in the interior of the structure.

17. The system of claim 16, wherein the specified number is seven.

18. The system of claim 13, wherein the merging the sub-cells is performed only in a specified direction.

19. The system of claim 18, wherein the specified direction is selected from the group consisting of horizontal and vertical.

20. The system of claim 13, wherein the cell and sub-cells are tetrahedral.

21. The system of claim 20, wherein partitioning includes barycentric subdivision.

22. The system of claim 13, wherein the stopping condition allows partitioning to be carried out to a maximum resolution of the three-dimensional printing hardware.

23. The system of claim 13, wherein the stopping condition includes a constraint on at least one of a total required build material, a total required build time, a desired density of the structure, a minimum void volume, and a maximum void volume.

24. The system of claim 13, wherein the control circuitry is further configured to control the three-dimensional printing hardware to fabricate the three-dimensional object, such that the one or more enclosed volumes of the surface are filled with cells that remain after the stopping condition is satisfied.

25. The system of claim 13, wherein the merging condition includes a constraint selected from the group consisting of:

a constraint on an overall mass of the structure, a constraint on a density of the structure, and a constraint on a location of a center of mass of the structure.

26-37. -37. (canceled)