Auto tip calibration in an extrusion apparatus

• US 20070228592A1
• Filed: 04/03/2006
• Published: 10/04/2007
• Est. Priority Date: 04/03/2006
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Dunn, Benjamin, Comb, James, Erickson, Hans, Wanzek, Jason
• Granted Patent: US 7,680,555 B2
• Time in Patent Office: Days
• US Class Current: 264/40.400
• 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 64/393 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 50/02 for controlling or regulating additive manufacturing processes

Abstract

The present invention is a method for performing a calibration routine of a deposition device in a three-dimensional modeling machine that deposits a material to build up three-dimensional objects as directed by a controller on a substrate mounted on a platform. The method comprises generating a material build profile, which represents a three-dimensional structure at defined locations. A relative position of the material build profile is then determined. An expected build profile is identified and then compared to the determined relative position of the material build profile to identify any difference which represents an offset. The modeling system then positions the deposition device based upon the offset.

Claims

1. A method for performing a calibration routine in a three-dimensional modeling machine that builds-up three-dimensional objects as directed by a controller by depositing modeling material with a deposition device onto a substrate mounted on a platform, the method comprising:

generating a material build profile, wherein the material build profile represents a three-dimensional structure at defined locations;

determining a relative position of the material build profile;

identifying an expected build profile;

comparing the relative position of the material build profile to an expected build profile to determine an offset; and

positioning the deposition device based upon the offset.

2. The method of claim 1, wherein the step of determining the relative position of the material build profile measures a height of the material build profile.

3. The method of claim 1, wherein the step of determining the relative position of the material build profile senses a side surface of the material build profile.

4. The method of claim 1, wherein the step of generating the material build profile places a prefabricated three-dimensional pad onto the substrate of the three-dimensional modeling machine.

5. The method of claim 1, wherein the step of generating the material build profile deposits material by the deposition device of the three-dimensional modeling machine onto the substrate.

6. The method of claim 1, wherein the step of identifying an expected build profile determines a relative position of a second three-dimensional structure created by a second deposition device of the three-dimensional modeling machine.

7. The method of claim 1, wherein the step of identifying an expected build profile determines an expected location of the material build profile in relation to an origin.

8. The method of claim 7, wherein the expected location of the material build profile represents a height of the material build profile above the substrate which is determined by multiplying a predetermined number of layers that are required to generate the material build profile by a desired height of each of the number of layers.

9. The method of claim 7, wherein the expected location of the material build profile represents an expected position of a side surface of the material build profile relative to the origin.

10. The method of claim 1, wherein the expected build profile is provided as an input to the three-dimensional modeling machine.

11. The method of claim 1, wherein the expected build profile is a known value from a prefabricated three-dimensional structure.

12. The method of claim 1, wherein the step of determining the relative position of the material build profile uses a sensor assembly to sense a surface of the material build profile at a specific location.

13. The method of claim 12, wherein the sensor assembly includes an optical sensor.

14. The method of claim 12, wherein the sensor assembly includes a multi-axis electrical sensor.

15. The method of claim 1, wherein the deposition device is an extrusion tip.

16. The method of claim 1, wherein the steps are performed automatically.

17. A method for performing a calibration routine in a machine that builds-up three-dimensional objects under the operation of a controller by depositing modeling material onto a substrate mounted on a platform, the method comprising:

building a first pad on the platform using a first deposition device;

sensing a top surface of the first pad at a first defined X,Y location;

sensing a top surface of the substrate mounted on the platform at a second defined X,Y location;

using a combination of the sensed positions to calculate an actual height of the first pad; and

determining the difference between the actual height of the first pad and an expected height of the first pad to determine an offset.

18. The method of claim 17, and further comprising the step of positioning the platform in relation to the first deposition device based upon the offset.

19. The method of claim 17, wherein the offset has a tolerance of about 0.0005 inches.

20. The method of claim 17, and further comprising:

building a second pad on the platform using a second deposition device;

sensing a top surface of the second pad at a third defined X,Y location; and

determining the difference between the top surfaces corresponding to the sensing of the first pad and the sensing of the second pad to determine a relative offset between the first and second deposition devices.

21. The method of claim 20, wherein the relative offset between the first and second deposition devices has a tolerance of about 0.0005 inches.

22. The method of claim 20, and further comprising the step of positioning the platform in relation to the first deposition device and the second deposition device based upon the relative offset between the first and second deposition devices.