3-D model maker

• US 5,506,607 A
• Filed: 01/26/1995
• Issued: 04/09/1996
• Est. Priority Date: 01/25/1991
• Status: Expired due to Term

• Current Assignee: Solidscape, Inc. (Groupe Gorgé SA)
• Original Assignee: Sanders Prototypes Incorporated
• Inventors: Forsyth, John L., Philbrook, Kempton F., Sanders, Royden C. Jr.
• Primary Examiner(s): Hartary, Joseph W.
• Application Number:
  US08/378,947
• Time in Patent Office: 439 Days
• Field of Search: 347/1, 347/37, 347/6, 118/695, 156/58, 264/24, 425/375, 427/466
• US Class Current: 347/1
• CPC Class Codes: B29C 2037/90 Measuring, controlling or regulating
• CPC Class Codes: B29C 2791/002 Making articles of definite length, i.e. discrete articles B29C53/40 takes precedence
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B41J 2/01 Ink jet
• CPC Class Codes: B41J 3/4073 Printing on three-dimensional objects not being in sheet or web form, e.g. spherical or cubic objects B41J3/283, B41J3/286 take precedence; building up a 3D object using individual droplets from jetting heads B29C64/112
• CPC Class Codes: G01D 15/16 Recording elements transferring recording material, e.g. ink, to the recording surface printing recording elements G01D15/20
• CPC Class Codes: G01D 15/20 Recording elements for printing with ink or for printing by deformation or perforation of the recording surface, e.g. embossing
• CPC Class Codes: G01D 9/38 Producing one or more recordings, each recording being produced by controlling the recording element, e.g. stylus, in accordance with one variable and controlling the recording medium, e.g. paper roll, in accordance with another variable
• CPC Class Codes: G05B 2219/49031 Project particles, laser beam to point using two, more jets, beams, ballistic particle
• CPC Class Codes: G06K 15/00 Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printersprinting or plotting combined with another operation, e.g. with conveying, G06K17/00
• CPC Class Codes: G06K 15/22 using plotters
• CPC Class Codes: G06K 2215/0082 Architecture adapted for a particular function

Abstract

The 3-D Model Maker of the present invention is a device that builds three dimensional models of computer generated (e.g., CAD) structures by vector plotting layer-upon-layer applications of solidifiable substances. The layers are formed by expelling minuscule beads of the substances in liquid or flowable phase onto a platform from one or more jets, the jets and platform being relatively movable in X, Y and Z coordinate system. The beads are deposited along vectors, during X/Y relative movement, on the stage, one at a time, layer-upon-layer, to build the model. The jets and platform are moved relatively to one another in accordance with instructions from the computer (controller) to form each layer in the X-Y plane (in a manner analogous to an X-Y vector plotter) and either the stage or the jets may move in the Z direction to allow the jets to form subsequent layers.

Claims

1. A 3-D model maker for producing a 3-D model by sequentially forming layer upon layer, by plotting vectors of modeling material, one layer at a time comprising:

a) a support means defining a surface for supporting the 3-D model during production;

b) a drop on demand jet means for ejecting bead producing drops of molten modeling material one drop at a time upon demand to meld with previously deposited beads, thereby to plot vectors of modeling material defining the layers;

c) mounting means mounting the jet means i) for simultaneous movement along at least two axes of an X, Y, Z axis coordinate system relative to said surface to move the jet means along any desired vector direction while said jet means plots said vectors of modeling material on said surface and ii) for movement of the jet means, when desired, along all three of the X, Y, Z axes of the system, relative to said surface; and

d) control means i) for providing vector plotting control of movement of the mounting means to move the jet means simultaneously along the at least two axes of the X, Y, Z axis coordinate system, ii) for controlling the timing of the ejection of bead producing drops of molten modeling material by the jet means to overlap previously deposited beads to a desired extent and to meld with previously deposited beads to generate vectors of modeling material, defined by the beads, in any and all directions required to produce, layer by layer by vector plotting, at least the other surface defining walls of the model being formed with a desired surface quality, and iii) for providing model fill and support control of deposition of at least one of molten modeling material, a molten fill and support material, and a powder fill and support material, to produce at least one of support for cantilever portions and other overhanging portions of the model during production and filling interior spaces of the model by at least one of vector plotting, raster scanning, spraying and deposition.

2. A 3-D model maker according to claim 1 wherein:

a) the surface is flat and extends normal to the Z coordinate;

b) the mounting means is for simultaneous movement of the jet means relative to the surface along the X and Y coordinates to define the vectors in any desired direction to form a layer; and

c) the control means controls the mounting means for movement of the jet means relative to the surface along the Z coordinate after formation of a layer and prior to formation of a next subsequent layer.

3. A 3-D model maker according to claim 2 comprising a model shaving system moveable to shave the model to a desired height along the Z coordinate when desired;

and

coupling means for selectively coupling said shaving system to said mounting means for movement thereby, under control of the control means, when shaving is desired and uncoupling said shaving system from said mounting means when shaving is not desired.

4. A 3-D model maker according to claim 3 wherein said coupling means comprises electromagnets located on at least one of said mounting means and said shaving system.

5. A 3-D model maker according to claim 1 further comprising a responsive means for responding to vector plotting speed, acceleration and direction for controlling bead drop rate of said jet means to provide a constant bead pitch while said jet means moves along a vector during speed and direction changes of said vector, thereby providing a wall of modeling material having a substantially constant width and having sides with a desired surface quality regardless of speed, acceleration, angle or curvature of said vector.

6. A 3-D model maker according to claim 5 wherein said responsive means provides the control on the basis of vector plotting speed and direction during acceleration of the jet means and on the basis of time when jet means speed is substantially constant.

7. A 3-D model maker according to claim 5 wherein said vector plotting speed and direction are detected by X and Y coordinate encoders and the responsive means receives and responds to outputs of these, the direction of plot being determined continually by calculating one of the arc tangent and the sum of the squares of the instantaneous ratio of encoder outputs.

8. A 3-D model maker according to claim 7 wherein constant bead pitch is achieved by controlling the responsive means to fire said jet means, in response to the X and Y coordinate encoder that is closer in angle to said calculated direction, in dependence upon that angle.

9. A 3-D model maker according to claim 1 wherein the jet means comprises:

a) a jet tip assembly defining an orifice for ejecting bead forming drops of molten modeling material;

b) a jet reservoir for storing molten modeling material for supply to said orifice;

c) an actuator for ejecting a drop on demand from the orifice;

d) a capillary tube connecting the jet tip and the jet reservoir to counterbalance head pressure applied by the molten material in the jet reservoir to allow vertically downward ejection of drops by the jet means during operation thereof without dripping when the jet means is idle.

10. A 3-D model maker according to claim 9 wherein:

the jet reservoir defines a space above the molten material to act as an isolator from hydraulic surges otherwise occurring as the means is moved while forming a layer.

11. A 3-D model maker according to claim 10 wherein the changes in pressure in the space as the level of the molten material in the jet reservoir falls siphons molten material from a supply reservoir to replenish the jet reservoir.

12. A 3-D model maker according to claim 11 wherein:

a) the supply reservoir is located relative to the jet means to provide a desired head of molten material relative to the molten material in the jet reservoir to facilitate the replenishment;

b) the supply reservoir has a molten material surface level detector; and

c) a molten material storage reservoir is provided with supply means responsive to the surface level detector for maintaining the surface level in the supply reservoir substantially constant.

13. A 3-D model maker according to claim 10 wherein the space is formed by a phase change of the modeling material in the jet reservoir from solid to molten, the jet means being provided with a heater to cause the phase change and to maintain the molten condition of the material during modeling.

14. A 3-D model maker according to claim 10 wherein the space is maintained relatively constant upon removal and replacement of a jet reservoir closure cap by the provision of space vent openings located to be opened by the cap immediately upon movement of the cap at the commencement of cap removal and to be closed by the cap immediately before full replacement of the cap during cap replacement.

15. A 3-D model maker according to claim 9 wherein the actuator is a piezo actuator to produce, upon energization, an acoustic energy wave in and volumetric constriction of the molten material in the jet means between the orifice and the jet reservoir thereby to cause the ejection of a bead forming drop of the molten material from the orifice.

16. A 3-D model maker according to claim 1 comprising:

a) an automated jet cleaning station; and

b) a jet failure detection means for detecting failure of the jet means by detecting a variation in a ringing of an end of a jet means actuating pulse exceeding variations in the ringing when the jet means is functioning properly, wherein

c) the control means responds to a detected jet means failure by taking the jet means off line and to the jet cleaning station and, upon rectification of the failure, to return the jet to the point of failure to recommence modeling from the point of failure.

17. A 3-D model maker according to claim 16 wherein the cleaning station comprises:

a) a thermistor operative and positioned relative to the direction of drop ejection by a jet means to confirm failure of the jet means; and

b) a cleaning device for purging a failed jet means upon confirmation of failure.

18. A 3-D model maker according to claim 16 wherein the failure detection means comprises:

means for establishing and storing in the control means a signature profile signal which corresponds to the ringing of the end of a jet means actuating pulse when the jet means is operating properly;

means for comparing the current ringing profile of the end of subsequent such pulses with the signature ringing profile;

and means for generating a jet means failure indicating signal upon detection of a current ringing profile differing from the signature ringing profile by more than normal variations in the ringing profile of that jet means when operating properly.

19. A 3-D model maker according to claim 1 wherein the control means controls the mounting means to move the jet means relative to the surface always in vector motion at least to separately produce more than one wall element to define a wall of the model in each layer, thereby to enhance exposed surface finish.

20. A 3-D model maker according to claim 1 wherein the surface is constructed to firmly engage the first to be generated layer of modeling material and to permit release of that layer when desired by one of a) heating the layer to a release temperature and b) dissolving the material defining the surface.

21. A 3-D model maker according to claim 1 wherein, in order to minimize shrinkage and warpage, the control means causes the beads defining the vectors of a model layer to be formed in two passes:

a) during a first pass of the jet means relative to the surface, each alternate bead of the desired vectors are formed; and

b) during a second pass of the jet means relative to the surface, the missing intermediate beads are formed.

22. A 3-d model maker according to claim 1 wherein there are at least two jet means, a first for ejecting a molten modeling compound (MC) for building the structure of the model and a second for ejecting a molten support compound (SC) for depositing removable material to support cantilevers and other overhanging features of a model during production thereof.

23. A 3-D model maker according to claim 22 wherein there are three jet means, a third for ejecting one of molten modeling compound and molten filling material in larger quantities per drop than the first jet means, whereby the first jet means may be used to build exposed walls of the finished model using vector plotting and the third jet means may be used to quickly fill voids in the model which require filling using raster plotting.

24. A 3-D model maker according to claim 1 wherein the control means causes lattice reinforcing webs to be deposited layer upon layer to reinforce walls of hollow models.

25. A 3-D model maker according to claim 24 wherein the control means causes the webs to be formed of a plurality of unidirectional walls oriented to provide desired reinforcement.

26. A 3-D model maker according to claim 24 wherein the control means causes the webs to be formed of a plurality of bi-directional walls.

27. A 3-D model maker according to claim 24 wherein the control means Causes the webs to form an interconnecting inner wall structure that is intimately connected with an outer wall structure formed during the formation of the same layer.

28. A 3-D model maker according to claim 24 wherein adjacent a closed top model feature the control means causes molten material used to construct the webs to be deposited over the entirety of the closed top feature whereby the webs increase in thickness layer by layer until they meet to provide a continuous basis for the deposition of the closed top feature.

29. A 3-D model maker according to claim 1 comprising a model shaving system moveable to shave the model to a desired height along the Z coordinate when desired;

and

coupling means for selectively coupling said shaving system to said mounting means for movement thereby, under control of the control means, when shaving is desired, and uncoupling said shaving system from said mounting means when shaving is not desired.

30. A 3-D model maker according to claim 29 wherein said coupling means comprises electromagnets located on at least one of said mounting means and said shaving system.

31. A method of producing a 3-D model comprising the steps of:

a) providing a surface for supporting the 3-D model during production;

b) providing a drop on demand jet means mounted on a mounting means for simultaneous movement along X and Y coordinates, of an X, Y, Z coordinate system, parallel to the support surface;

c) providing a control means for i) controlling the timing of ejection of bead producing drops of modeling material one drop at a time, upon demand from the drop on demand jet means onto the support surface to overlap previously deposited beads to a desired extent and meld with previously deposited beads, thereby to produce vectors of modeling material, at least when forming Outer surface defining walls of the model, thereby forming outer surface defining walls having a desired surface finish, ii) controlling movement of the mounting means and support surface relative to each other in the X and Y coordinates simultaneously to generate vectors of modeling material in any and all directions required to produce a layer of the model by vector plotting at least when forming outer surface defining walls of the model, thereby forming outer surface defining walls having a desired surface finish, and iii) for providing model fill and support control of deposition of at least one of molten modeling material, a molten fill and support material, and a powder fill and support material, to produce at least one of support for cantilever portions and other overhanging portions of the model during production and filling interior spaces of the model by at least one of vector plotting, raster scanning, spraying and deposition;

d) moving the mounting means and the support surface relative to each other in the Z coordinate direction normal to the support surface under the control of the control means; and

e) repeating steps b), c) and d), as required to produce desired additional layer(s) until the model is complete.

32. A method according to claim 31 wherein a desired void in the model is filled with solid particles of filler material compatible with the modeling material, whereafter at least an upper surface of the solid particles, in the void, are adhered together by modeling material ejected from the drop on demand jet means.

33. A method according to claim 31 wherein the support surface is styrofoam.

34. A method of producing a 3-D model according to claim 31 comprising the step of controlling bead drop rate of said jet means, at least when forming exposed walls of the model when finished, in response to vector plotting speed, acceleration and direction to provide a constant bead pitch while said jet means moves along a vector, regardless of speed, acceleration, angle or curvature of said vector and thereby provide said walls of modeling material having a substantially constant width and having sides with a desired surface quality regardless of speed, acceleration, angle or curvature of said vector.

35. A method of producing a 3-D model according to claim 34 comprising the step of controlling said bead drop rate on the basis of vector plotting speed and direction during acceleration of the jet means and on the basis of time when jet means speed is substantially constant.

36. A method of producing a 3-D model according to claim 34 comprising the steps of:

detecting vector plotting speed and direction of the jet means with X and Y coordinate encoders and controlling the bead drop rate in response to output of the encoders; and

continually determining the direction of plot by calculating one of the arc tangent and the sum of the squares of the instantaneous ratio of encoder outputs.

37. A method of producing a 3-D model according to claim 36 controlling the bead drop rate in response to the X and Y coordinate encoder that is closer in angle to said calculated direction, in dependence upon that angle, to maintain a constant bead pitch.

38. A method of producing a 3-D model according to claim 31 comprising the step of shaving the model to a desired height along the Z coordinate when desired by:

a) halting ejection of bead producing drops from the jet means;

b) moving the mounting means to a shaving means rest position;

c) coupling the mounting means to a shaving means, parked in the rest position, for moving the shaving means with the mounting means and shaving the model to a desired height along the Z coordinate;

d) moving the mounting means to the rest position upon completion of shaving and uncoupling the shaving means from the jet means, thereby parking the shaving means in the rest position; and

c) resuming ejection of bead producing drops from the jet means, with the shaving means parked in the rest position, to produce additional layers if desired.

39. A method of producing a 3-D model according to claim 38 comprising the step of providing electromagnets on at least one of said mounting means and said shaving and energizing these electromagnets for the selectively coupling of said shaving system to the mounting means.

40. A method of producing a 3-D model according to claim 31 comprising the step of ejecting the bead producing drops of material at a temperature high enough to ensure that the beads of modeling material are still at least partially molten when the beads impact previously deposited beads, at least when forming one of an interior and outer wall of a model, to fuse the beads to and blend into the previously deposited beads thereby to enhance the surface finish of the wall.

41. A method of producing a 3-D model according to claim 40 comprising the step of ejecting the bead producing drops of material such that a new bead at least partially overlaps a previously deposited bead in the same layer thereby to enhance the surface finish of the wall.

42. A method of producing a 3-D model according to claim 41 comprising the step of moving the jet means to form a double wall of said overlapping beads, at least when forming exposed walls of the model, thereby to enhance the surface finish of the wall.

43. A method of producing a 3-D model according to claim 31 comprising the step of filling interior portions of the model with a powder material and adhering at least an upper surface of particles of the powder material together by ejecting drops modeling material from the drop on demand jet means onto the upper surface of the particles.

44. A method of producing a 3-D model according to claim 31 comprising the steps of:

a) forming outer and interior exposed walls of the model by firing the drop on demand jet means at a control frequency at which beads of modeling material of a substantially consistent size are ejected from the jet means;

b) filling interior portions of the model using raster scanning and by firing the jet means at a frequency, higher than the control frequency, that coincides with a resonant frequency of the jet means, thereby ejecting beads from the jet means that are substantially larger than beads ejected from the jet means at the control frequency thereby to increase rate of deposition of modeling material when filling the interior portions relative to rate of deposition of modeling material at the control frequency.