Method for building three-dimensional objects with thin wall regions

• US 20090018685A1
• Filed: 07/11/2007
• Published: 01/15/2009
• Est. Priority Date: 07/11/2007
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Holzwarth, Donald J.
• Granted Patent: US 8,050,786 B2
• Time in Patent Office: Days
• US Class Current: 700/98
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/49035 Reconstruct boundary volume from stack of layer contours, sections
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: G06T 17/20 Finite element generation, e.g. wire-frame surface description, tesselation

Abstract

A method for modifying a computer-aided design model of a three-dimensional object, the method comprising establishing a threshold wall width, providing at least one sliced layer polyline of the computer-aided design model, determining a first distance between first and second portions of the at least one sliced layer polyline, and adjusting locations of the first and second portion to provide a second distance if the first distance is less than the threshold wall width, where the second distance is about equal to the threshold wall width, or greater.

Claims

1. A method for modifying a computer-aided design model of a three-dimensional object, the method comprising:

establishing a threshold wall width;

providing at least one sliced layer polyline of the computer-aided design model, the at least one sliced layer polyline comprising a first portion and a second portion;

determining a first distance between the first portion and the second portion; and

adjusting locations of the first portion and the second portion to provide a second distance between the first portion and the second portion if the first distance is less than the threshold wall width, wherein the second distance is about equal to the threshold wall width, or greater.

2. The method of claim 1, wherein the threshold wall width ranges from about 150% of a road width of build material deposited from a layered deposition system to about 200% of the road width.

3. The method of claim 2, wherein the threshold wall width ranges from about 160% of the road width to about 180% of the road width.

4. The method of claim 1, wherein the threshold wall width is about equal to the road width.

5. The method of claim 1, wherein the first portion comprises a first vertex and the second portion comprises a second vertex, and wherein adjusting the locations of the first portion and the second portion comprises:

generating a first adjustment vector for the first vertex;

generating a second adjustment vector for the second vertex;

repositioning the first vertex based on the first adjustment vector; and

repositioning the second vertex based on the second adjustment vector.

6. The method of claim 1, wherein the first portion comprises a first vertex interconnecting a first segment and a second segment, wherein the second portion comprises a second vertex interconnecting a third segment and a fourth segment, and wherein determining the first distance comprises:

determining a first minimum distance between the first vertex and the third and fourth segments; and

determining a second minimum distance between the second vertex and the first and second segments.

7. The method of claim 1, further comprising generating a perimeter tool path based on the sliced layer polyline having the first portion and the second portion at the adjusted locations.

8. A method for modifying a computer-aided design model of a three-dimensional object, the method comprising:

establishing a threshold wall width;

providing at least one sliced layer polyline of the computer-aided design model, the at least one sliced layer polyline comprising a plurality of vertices and a plurality of segments;

determining a first distance between a first vertex of the plurality of vertices and at least one segment of the plurality of segments; and

adjusting a location of the first vertex if the distance is less than the threshold wall width.

9. The method of claim 8, wherein the threshold wall width is a function of a road width of build material deposited from a layered deposition system.

10. The method of claim 8, wherein determining the first distance between the first vertex and the at least one segment comprises:

searching for at least a second vertex of the plurality of vertices within a predetermined distance from the first vertex, wherein the second vertex is connected to the at least one segment; and

determining a minimum distance between the first vertex and the at least one segment.

11. The method of claim 8, wherein adjusting the location of the first vertex comprises:

generating an adjustment vector for the first vertex as a function of the threshold wall width; and

repositioning the first vertex based on the adjustment vector.

12. The method of claim 8, wherein the threshold wall width is a first threshold wall width, the method further comprising:

establishing a second threshold wall width; and

adjusting the location of the first vertex if the distance is less than the second threshold wall width.

13. The method of claim 8, further comprising generating a perimeter tool path based on the sliced layer polyline having the first vertex at the adjusted location.

14. A method for modifying a computer-aided design model of a three-dimensional object, the method comprising:

establishing a threshold wall width;

providing at least one sliced layer polyline of the computer-aided design model, the at least one sliced layer polyline comprising;

a first vertex interconnecting a first segment and a second segment; and

a second vertex interconnecting a third segment and a fourth segment;

determining a first minimum distance between the first vertex and the first and second segments;

determining a second minimum distance between the second vertex and the third and fourth segments;

adjusting a location of the first vertex if the first minimum distance is less than the threshold wall width; and

adjusting a location of the second vertex if the second minimum distance is less than the threshold wall width, wherein an adjusted distance between the adjusted first vertex and the adjusted second vertex is about equal to the threshold wall width, or greater.

15. The method of claim 14, wherein the threshold wall width ranges from about 150% of a road width of build material deposited from a layered deposition system to about 200% of the road width.

16. The method of claim 15, wherein the threshold wall width ranges from about 160% of the road width to about 180% of the road width.

17. The method of claim 14, wherein the threshold wall width is about equal to the road width.

18. The method of claim 14, wherein adjusting the location of the first vertex comprises:

generating a first adjustment vector for the first vertex as a function of the threshold wall width; and

repositioning the first vertex based on the first adjustment vector.

19. The method of claim 18, wherein adjusting the location of the second vertex comprises:

generating a second adjustment vector for the second vertex as a function of the threshold wall width; and

repositioning the second vertex based on the second adjustment vector.

20. The method of claim 14, wherein the at least on sliced layer polyline comprises a first polyline and a second polyline, and wherein the first vertex is located on the first polyline and the second vertex is located on the second polyline.