Mid-part in-process inspection for 3D printing

Patent metadata

Field	Value
Publication number	US-11014305-B2
Application number	US-201816108870-A
Country	US
Kind code	B2
Filing date	Aug 22, 2018
Priority date	Mar 22, 2013
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

According to one aspect, embodiments herein provide a method for in-process inspection of a 3D printed part with a 3D printer, comprising slicing a three dimensional model to define a plurality of shell volumes, for substantially each shell volume, generating a toolpath for depositing a printing material shell corresponding to the shell volume, transmitting, together with an identification, the toolpaths defining the printing material shells for deposition by a 3D printer, receiving, together with the identification, from the 3D printer a scanned surface profile of a printing material shell, and computing a process inspection including, according to the identification, a comparison between a received scanned surface profile and a toolpath defining a printing material shell.

First claim

What is claimed is:

1. A 3D printer, comprising:
a printing material deposition head configured to trace toolpaths to deposit printing material shells,
a range scanner positioned to measure surface profiles of printing material shells, the range scanner positioned with respect to the printing material deposition head such that surface profile measurements are taken with a center axis of the range scanner being continually angled no more than 30 degrees from a normal to that portion of the surface profile being measured;
a receiving circuit configured to receive the toolpaths defining the printing material shells and an associated identification;
a processor configured to associate the identification to the measured surface profiles;
a transmitting circuit configured to return the associated identification and the measured surface profiles of printing material shells, following a deposition by the printing material deposition head; and
a memory storing a definition of a boundary shape, wherein the processor is further A configured to execute instructions performing a comparison between the boundary shape and at least one of: the measured surface profile and the toolpath defining a printing material shell.

2. The 3D printer according to claim 1 , wherein the transmitting circuit is further configured to return the associated identification and the measured surface profiles of material shells, following a mid-part deposition by the printing material deposition head.

3. The 3D printer according to claim 1 , wherein the receiving circuit is further configured to receive a selection of printing material shells to be scanned, the processor is further configured to associate the selection with corresponding measured surface profiles, and the transmitting circuit is further configured to return the associated identification and the corresponding measured surface profiles of material shells following each deposition corresponding to the selection of printing material shells to be scanned.

4. The 3D printer according to claim 1 , further comprising a user input device, wherein the receiving circuit is further configured to receive a selection of printing material shells to be scanned from the user input device.

5. The 3D printer according to claim 4 , wherein the receiving circuit is further configured to receive the selection of printing material shells to be scanned associated with the toolpaths defining the printing material shells and the associated identification.

6. The 3D printer according to claim 4 , further comprising a user input device, wherein the processor is further configured to acquire user input from the user input device to generate the definition of the boundary shape.

7. The 3D printer according to claim 1 , wherein the range scanner has a resolution in the ranging direction no less than 1/10 of a thickness of the printing material shell to be scanned.

8. The 3D printer according to claim 1 , further comprising an image capture device directed at the printing material shells to be scanned and configured to capture images of the printing material shells associated with at least one of the printing material shells or the measured surface profiles.

9. The 3D printer according to claim 1 , wherein the processor is further configured to generate the boundary shape from at least one of the toolpaths or the measured surface profiles.

10. The 3D printer according to claim 1 , wherein the boundary shape comprises a boundary primitive including at least one of a circle, a cylinder, a line, a plane, a polygon, or a prism polyhedron.

11. The 3D printer according to claim 1 , wherein the processor is further configured to monitor the boundary shape and transmit a signal to change a toolpath when a threshold representative of the boundary shape is crossed.

12. The 3D printer according to claim 11 , wherein the signal to change the toolpath is a signal to pause deposition of a printing material shell.

13. The 3D printer according to claim 1 , wherein the processor is further configured to receive a calibration target toolpath, execute instructions to cause the printing material deposition head that traces toolpaths to deposit printing material shells to form a 3D printed calibration target and such that the range scanner scans the 3D printed calibration target to form a calibration target surface profile, and compute a process calibration including a comparison between the calibration target surface profile and the calibration target toolpath.

14. The 3D printer according to claim 13 , wherein the processor is further configured to receive a tolerance definition for the 3D printed calibration target, and execute instructions to adjust the toolpaths based on the 3D printed calibration target, the tolerance, and the scanned surface profiles of the 3D printed calibration target.

15. A 3D printer, comprising:
a print bed upon which a part can be printed;
a printing material deposition head configured to trace toolpaths to deposit printing material shells upon the print bed and upon previously deposited printing material shells, the printing material deposition head movably supported by a gantry for substantially parallel movement;
a range scanner positioned to measure surface profiles of the print bed and of printing material shells, the range scanner located to move together with the printing material deposition head as supported by the gantry and to scan height in a direction normal to the printing bed;
a receiving circuit configured to receive the toolpaths defining the printing material shells; and
a processor configured to execute instructions to activate the printing material deposition head to cause the range scanner to scan the print bed to form a difference contour representing a difference between a surface of the print bed and the gantry, the difference contour used to generate a compensation array comprising compensation amounts for a plurality of sites on the surface of the print bed, the processor further configured to control the printing material deposition head to deposit printing material compensated according to the compensation amounts.

16. The 3D printer according to claim 15 , wherein the processor is further configured to execute instructions to activate heat-generating components of the printer such that the printer reaches an operating temperature before scanning the print bed to form the difference contour.

17. The 3D printer according to claim 15 , wherein the compensation array is altered by one or more compensation factors comprising a printing deposition distance from the print bed, a printing deposition volume rate, a printing deposition height, and a printing deposition X-Y dependence.

18. A 3D printer, comprising:
a printing material deposition head configured to trace toolpaths to deposit printing material shells,
a laser positioned to measure surface profiles of printing material shells, the laser positioned with respect to the printing deposition head such that surface profile measurements are taken with a center axis of the laser being continually angled no more than 30 degrees from a normal to that portion of the surface profile being measured;
a receiving circuit configured to receive the toolpaths defining the printing material shells and an associated identification;
a processor configured to associate the associated identification to the measured surface profiles; and
a transmitting circuit configured to return the associated identification and the measured surface profiles of printing material shells, following a deposit

Assignees

• Markforged Inc

Inventors

• Mark Gregory Thomas

Classifications

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• G05B19/4099

  Surface or curve machining, making three-dimensional [3D] objects, e.g. desktop manufacturing · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C64/118 Primary

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title