Multi-material toolpath generation for direct metal deposition

• US 6,859,681 B1
• Filed: 09/27/2000
• Issued: 02/22/2005
• Est. Priority Date: 09/27/1999
• Status: Active Grant

• Current Assignee: DM3D Technology, LLC
• Original Assignee: The POM Group
• Inventors: Alexander, Paul
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): CABRERA, ZOILA E
• Application Number:
  US09/671,536
• Time in Patent Office: 1,609 Days
• Field of Search: 700/97, 700/98, 700/118, 700/119, 700/180, 700/182, 700/184, 204/401
• US Class Current: 700/184
• 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 2219/35082 Product, feature based modeling, geometric and engineering info
• CPC Class Codes: G05B 2219/35159 With nominal blank and model in memory define tool path and machine workpiece
• CPC Class Codes: G05B 2219/49245 2-5-D pocket machining
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method of modeling multiple material parts for additive manufacturing processes such direct metal deposition operates within the constraints of a single material CAD system. Each material is modeled separately as a single or multiple solid part, under the assumption that there are no internal multiple materials; that is, no voids for other material parts. The parts are ordered from the outer most geometry to the innermost geometry and Boolean operations are performed to calculate the final volume for each part. In use of the invention, should any design changes occur, only the parts as originally defined need to be modified, and the method is reapplied. The method is applicable to the generation of CAM cutting paths for 2½-D and 3-D geometries by pocket machining with spiral-in, spiral-out, and arbitrary direction raster tool paths using stock material with and without reflection, depending upon the geometry. Single- and multi-material files may be merged one toolpath file, and commands may be embedded for closed- or open-loop control of the fabrication process.

Claims

1. A method of modeling a tool path in an additive manufacturing process enabling multi-material parts to be fabricated without material interference, the method comprising the steps of:

separately modeling each material as a single or multiple solid part under the assumption that multiple materials or voids are not present;

ordering the parts from the outermost geometry to the innermost geometry; and

performing Boolean operations on the ordered parts to calculate the final volume for each part.

2. The method of claim 1, wherein all of the steps are carried out using a CAD system limited to single-material designs.

3. The method of claim 1, wherein the tool path is a spiral-in, spiral-out, arbitrary direction raster path, or a combination thereof.

4. The method of claim 1, further including the step of reflecting the geometries to accommodate overhang or undercut features.

5. The method of claim 1, further including the step of embedding commands as appropriate to accommodate closed- or open-loop control over the fabrication process.

6. The method of claim 1, further including the steps of:

generating multiple tool paths; and

merging the toolpaths into a single toolpath file.