3D printing with kinematic coupling

Patent metadata

Field	Value
Publication number	US-9539762-B2
Application number	US-201514605752-A
Country	US
Kind code	B2
Filing date	Jan 26, 2015
Priority date	Mar 22, 2013
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A three dimensional printer incorporates a kinematic coupling between the build platform and movable stage which holds the build platform, of three curved protrusions attached to one of the build platform or the movable stage and six locating features formed in receivers of the other. At least two flexures differentially change a Z position of each of two of the curved protrusions. 3D printing is paused at a preset level of completion, and the build platform may be removed for external operations. A print resume circuit resumes printing of additional printed layers at the previous position in response to a return detection circuit that responds to an input (e.g., a touch screen confirmation).

First claim

What is claimed is:

1. A three dimensional printer, comprising:
a non-square rectangular build platform for receiving a part deposited by a three dimensional printing process;
a movable stage supporting the build platform;
a kinematic coupling between the build platform and movable stage which holds said build platform, comprising:
three curved protrusions attached to one of the build platform or the movable stage;
six locating features formed in receivers of the remaining one of the build platform and the movable stage, providing for six points of contact between the curved protrusions and the locating features; and
at least two flexures, one flexure operative with respect to each of two of the three curved protrusions attached to differentially change a Z position of at least one of the points of contact;

a print pause circuit that pauses three dimensional printing;
a completion level detection circuit that responds to a preset level of completion of a part to activate the print pause circuit;
removal circuit that responds to the print pause circuit to present the build platform to be removed;
a print resume circuit that resumes printing of additional printed layers; and
a return detection circuit that responds to an input associated with the return of the build platform to activate the print resume circuit,
wherein the three curved protrusions are arranged in a non-equilateral triangle in a plane about the perimeter of the non-square rectangular build platform such that one side of the triangle is longer than the remaining two.

2. The three dimensional printer according to claim 1 , wherein
each of the three curved protrusions comprises at least part of a semi-sphere.

3. The three dimensional printer according to claim 1 , wherein
the six locating features comprise three two-point locating features.

4. The three dimensional printer according to claim 3 , wherein at least one of the six points of contact is oriented in a direction other than perpendicular to a centroid of a coupling triangle among the three curved protrusions.

5. The three dimensional printer according to claim 1 , wherein
the six locating features comprise one three or more point locating feature, one two point locating feature, and one single point locating feature.

6. The three dimensional printer according to claim 1 , wherein each of the three curved protrusions is arranged to be, in a coupled position, no more than substantially ½ mm from a rare earth magnet arranged among the six locating features, each rare earth magnet having a pulling force gradient over 5 mm distance from 0 to 0.2 lb. of force at 5 mm to 1 to 3 lb. of three at contact, the rare earth magnet pulling the protrusions into a preload condition and giving tactile and auditory feedback by emphasizing a contact impact as a click.

7. The three dimensional printer according to claim 6 , wherein the protrusions are held in the preload condition by gravity in addition to by the rare earth magnets.

8. The three dimensional printer according to claim 1 , where each of the three curved protrusions attached to one of the build platform or the movable stage is configured and arranged to mate with, upon the remaining one of the build platform or the movable stage, a grooved receiving member having two coupling surfaces joined by two guiding surfaces, the two coupling surfaces being locating features providing two points of contact, and the two guiding surfaces being approximately perpendicular and adjacent to the two coupling surfaces.

9. A method of performing multi-step operations on an article with a 3D printer, comprising:
receiving a non-square rectangular build platform on a movable stage;
locating the build platform to the movable stage with a six point contact alignment between three curved protrusions and six locating features, wherein the three curved protrusions are arranged in a non-equilateral triangle in a plane about the perimeter of the non-square rectangular build platform such that one side of the triangle is longer than the remaining two;
constraining movement of at least two of the three curved protrusions using at least two individual flexures each constructed to flex two leaves in parallel to constrain movement of a corresponding one of the three curved protrusions to move substantially only in the Z height direction;
holding the build platform on the movable stage to the kinematic coupling;
receiving printed layers of the article on the build platform;
checking, with a completion level detection circuit, whether the 3D printed layers of the article have reached a preset level of completion
pausing, with a print pause circuit, the receiving of 3D printed layers when the preset level of completion is reached;
presenting, with a removal circuit, the build platform to be removed;
removing the build platform from the six point contact alignment for operations outside the movable stage;
returning the build platform to the six point contact alignment following the operations outside the movable stage;
detecting, with a return detection circuit, the return of the build platform to the six point and contact alignment; and
resuming, with a print resume circuit, 3D printing of additional layers without further adjusting the Z height of any of the three curved protrusions.

10. The method according to claim 9 , further comprising:
leveling the build platform by adjusting a Z height of the at least two of the three curved protrusions.

11. The method according to claim 9 , further comprising:
reindexing the build platform to a Cartesian origin in at least two of X, Y, and Z directions before resuming the 3D printing of additional layers without further adjusting the Z height of any of the three curved protrusions.

12. The method according to claim 9 , further comprising:
receiving a functional insert;
receiving data representative of a location of gluing operations which deposit material to affix a functional insert to the article;
depositing material in the location of gluing operations to affix the functional insert to the article; and
continuing to receive printed layers of the article on the build platform.

13. The method according to claim 9 , further comprising:
receiving a functional insert;
receiving data representative of printing instructions which deposit material to overmold the functional insert; and
continuing to receive printed layers of the article on the build platform.

14. The method according to claim 9 , further comprising:
forming at least one layer in the shape of one of an inner or an outer contour of a functional insert;
guiding the functional insert;
receiving a functional insert;
depositing material adjacent the shape of one of an inner or an outer contour of the functional insert.

Assignees

• Markforged Inc

Inventors

• Durand Keith
• Woodruff Rick Bryan
• Mark Gregory Thomas

Classifications

• B29K2071/00

  Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B29C70/16

  using fibres of substantial or continuous length {(non-woven fabrics per se D04H3/00)} · CPC title

• B29K2063/00

  Use of {EP, i.e.} epoxy resins {or derivatives thereof}, as moulding material · CPC title

• B29K2025/08

  Copolymers of styrene, e.g. AS or SAN, i.e. acrylonitrile styrene (B29K2055/02 takes precedence) · CPC title