WO2021211088A1

WO2021211088A1 - Additively manufacturing a first 3d object at least partially containing a second 3d object

Info

Publication number: WO2021211088A1
Application number: PCT/US2020/027937
Authority: WO
Inventors: Wei Huang; William J. Allen; Gary J. Dispoto
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2020-04-13
Filing date: 2020-04-13
Publication date: 2021-10-21

Abstract

A device is to additively manufacture a 3D assembly, which comprises a first 3D object and a second 3D object. The second 3D object is at least partially contained within the first 3D object, and is releasably secured relative to the first 3D object, in a position to defer independent deployment of the second 3D object.

Description

ADDITIVELY MANUFACTURING A FIRST 3D OBJECT AT LEAST PARTIALLY CONTAINING A SECOND 3D OBJECT

Background

[0001] Additive manufacturing may revolutionize design and manufacturing in producing three-dimensional (3D) objects. Some forms of additive manufacturing may sometimes be referred to as 3D printing, and may produce 3D objects with complex attributes.

Brief Description of the Drawings

[0002] FIG. 1 is a block diagram schematically representing an example device and/or example method of additively manufacturing an example 3D object.

[0003] FIG. 2A is a diagram including an isometric view schematically representing an example first assembly including a first three-dimensional (3D) object at least partially containing an example second 3D object.

[0004] FIG. 2B is a sectional view as taken along lines 2B-2B of the example first assembly in FIG. 2A.

[0005] FIG. 3 is a block diagram and an isometric view schematically representing an example device and/or example method to additively manufacture a 3D object.

[0006] FIG. 4A is diagram including an isometric view schematically representing an example first assembly including a first 3D object containing an example second 3D object.

[0007] FIG. 4B is a sectional view as taken along lines 4B-4B of the example first assembly in FIG. 4A.

[0008] FIG. 4C is a diagram including a sectional view taken from the same position as shown for the sectional views of FIGS. 4B and 5B, except schematically representing a first 3D object containing a plurality of example second 3D objects embedded within a powder material within a cavity of the first 3D object. [0009] FIG. 5A is diagram including an isometric view schematically representing an example first assembly including a first 3D object at least partially containing an example second 3D object.

[0010] FIG. 5B is a sectional view as taken along lines 5B-5B of the example first assembly in FIG. 5A.

[0011] FIG. 6A is diagram including an isometric view schematically representing an example first assembly including a first 3D object at least partially containing an example second 3D object.

[0012] FIG. 6B is a sectional view as taken along lines 6B-6B of the example first assembly in FIG. 6A.

[0013] FIG. 7A is a diagram including a side sectional view schematically representing an example first assembly including a second 3D object nested within an example first 3D object.

[0014] FIG. 7B is a diagram including a side sectional view schematically representing an example first assembly including an example second 3D object nested within an example first 3D object, and an example third 3D object nested within the example second 3D object.

[0015] FIG. 8A is a diagram including a sectional view schematically representing an example first assembly including a first 3D object containing an example second 3D object with a latent fracturable release boundary between the respective first and second 3D objects.

[0016] FIG. 8B is a side view of the second 3D object in the example first assembly of FIG. 8A.

[0017] FIG. 9A is block diagram schematically representing an example object formation engine.

[0018] FIG. 9B is block diagram schematically representing an example control portion.

[0019] FIG. 9C is a block diagram schematically representing an example user interface.

[0020] FIG. 10 is flow diagram schematically representing an example method of additively manufacturing a first 3D object to constrain a second 3D object relative to cavity of the first 3D object. Detailed Description

[0021] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise.

[0022] At least some examples of the present disclosure are directed to additively manufacturing a single assembly which comprises a first three- dimensional (3D) object and a second 3D object. In some examples, second 3D object is at least partially contained within the first 3D object, and is releasably secured relative to the first 3D object, in a position to defer independent deployment of the second 3D object. The additive manufacturing may be performed as a method or by a device, and either of which may comprise at least some of substantially the same features and attributes as the examples described below in association with at least FIGS. 1-10.

[0023] In general terms, the second 3D object has a volume less than the first 3D object which enables at least partial containment of the second 3D object within the first 3D object. In some examples, the at least partial containment of the second 3D object within an interior portion of the first 3D object may render the second 3D object non-functional until the second 3D object becomes separated from the first 3D object. With this in mind, in some examples upon separation of the second 3D object from the first 3D object, the second 3D object is configured to function independently of the 3D object, i.e. operation of the second 3D object does not depend on the first 3D object. In some examples, the first 3D object has a function or purpose in addition to containing the second 3D object. [0024] In some examples, the first 3D object comprises a purpose, function, structure, and/or appearance different from a purpose, function, structure and/or appearance solely of containing the second 3D object. In some such examples, the first 3D object comprises a non-cage structure and/or a non-cage function, wherein a cage may comprise a network of spaced apart, connected bars, elements, etc.

[0025] In one aspect, by providing both a first and second 3D object as part of a single assembly in the above-described manner, examples of the present disclosure may optimize product recyclability (recycling cost-efficiency) and supply chain efficiencies (optimizing logistics of OEM supply). In some examples, both the first and second 3D objects can be printed simultaneously (i.e. together) as part of a single assembly, thereby increasing efficiency in additively manufacturing 3D objects. In addition, in some such examples, storage of spare parts may be simplified because a spare part(s) (e.g. a second 3D object) may be stored within another part (e.g. the first 3D object) instead of taking up space on a shelf or other storage location. Via such arrangements, the spare part also can be readily available at the machine of interest, instead of having to be retrieved from a different location. In some instances, the first 3D object may have a lower priority than the second 3D object so that when access to the second 3D object is desired for use as a replacement part, the first 3D object may be at least partially destructed to free the second 3D object for deployment as the desired replacement part. In this way, the second 3D object may be quickly accessed and deployed while one waits for the normal supply chain to provide the replacement part (same as second 3D object). Alternatively, the second 3D object may serve as a permanent replacement part provided that the quality of the second 3D object is sufficiently high compared to an original equipment manufacturer (OEM) replacement part. In such arrangements, because a portion of the first 3D object is effectively salvaged by access to and use of the second 3D object, this arrangement reduces recycling costs at least because the amount of material to be recycled has decreased. Alternatively, the first 3D object may have a higher priority than the second 3D object, such that the second 3D object would not be accessed from the first 3D object until or unless the first 3D object has exceeded its useful life, is discontinued design/model, has broken, etc. With this in mind, upon failure of a first 3D object, such as a partial breakage of a portion of the first 3D object, the second 3D object may be accessed from the first 3D object and deployed independently from the first 3D object.

[0026] In some examples, multiple second 3D objects may be at least partially contained within a first 3D object instead of at least partially containing a single second 3D object. In some examples, all of the multiple second 3D objects are identical, while in some examples, at least some of the second 3D objects are different from each other.

[0027] In some examples, the second 3D object(s) may have a function related to the first 3D object. Accordingly, this relationship contributes to the efficiency of the product supply chain. On the other hand, in some examples the second 3D object(s) have a function unrelated to the function of the first 3D object.

[0028] As further described below, there are various ways in which the second 3D object may be partially contained or completely contained within the first 3D object.

[0029] These examples, and additional examples, are described later in association with at least FIGS. 1-10.

[0030] FIG. 1 is a block diagram schematically representing an example method 50 of additively manufacturing an example 3D object. As shown in FIG. 1 , example method 50 comprises additively manufacturing a single assembly which comprises a first 3D object and a second 3D object, wherein the second 3D object is at least partially contained within the first 3D object, and is releasably secured relative to the first 3D object, in a position to defer independent deployment of the second 3D object.

[0031] In some examples, a device, such as instructions stored in a non- transitory machine-readable storage medium for execution via a processor, may be used to implement this arrangement. In some examples, the device may comprise a print control portion comprising a processor programmed to perform the actions shown in FIG. 1. Either of these examples may be implemented via at least the examples described later in association with at least FIGS. 9A-9C. [0032] FIGS. 2A-2B provide an isometric view and sectional view, respectively, schematically representing one example 3D assembly 101 implementable via the example method 50 (and/or example device) of FIG. 1. In particular, FIG. 2A is a diagram 100 including an isometric view schematically representing an example 3D assembly 101 (e.g. single structure) including a first 3D object 105 at least partially containing an example second 3D object 150. Meanwhile, FIG. 2B is a sectional view as taken along lines 2A-2A of FIG. 2A.

[0033] As shown in FIG. 2A, the first 3D object 105 comprises a pair opposite end portions 102A, 102B, a top portion 106A, and opposite bottom portion 106B, and a front portion 104A and opposite back portion 104B. While the first 3D object 105 is represented in FIG. 2A as a rectangular cuboid for illustrative simplicity, it will be understood that first 3D object 105 may comprise a wide variety of shapes and sizes, and may comprise a functional article and/or an aesthetic (i.e. non-functional) article. As a functional article, the 3D object 105 may function as a stand-alone article in some examples, or may function as part of a larger machine or assembly, in some examples.

[0034] As further shown in FIGS. 2A-2B, the first 3D object 105 includes a recess 130, which defines a cavity 138. In some instances, the recess 130 may sometimes be referred to as an interior portion of the first 3D object 105. Flowever, such interior portions may comprise a wide variety of shapes and/or volumes other than the rectangular-cuboid-shaped recess 130 shown in FIGS. 2A-2B.

[0035] As shown in FIGS. 2A-2B, in some examples, the recess 130 may comprise a top wall 134 and side walls 131 , which include an inner surface 132. An opening 172 in the recess 130 is makes the entire cavity 138 readily accessible. As further shown in FIGS. 2A-2B, in some examples, the second 3D object is releasably secured relative to the first 3D object 105 within the recess 130 via a retention arrangement, such as element 160. While the element 160 is shown as extending from the top wall 134 in FIGS. 2A-2B, it will be understood that in some examples, the element 160 may extend from or be connected to side walls 131 in addition to, or instead of, relative to top wall 134. [0036] As further shown in FIGS. 2A-2B, the second 3D object 150 is partially contained within the cavity 138 and is not generally visible outside the first 3D object 105 in most instances. However, because the cavity is open to the environment, the second 3D object 150 is accessible via the cavity 138 without destruction of the first 3D object 105. Via this arrangement, the 3D assembly 101 is arranged to defer independent deployment of second 3D object 150. [0037] As previously noted, the recess 130 may comprise a wide variety of shapes and sizes, which may or may not depend on a size and/or shape of the first 3D object 105.

[0038] In some examples, the element 160 may comprise a structure which includes at least a portion which, subject to the application of force, is bendable, breakable, fracturable, etc. to allow the second 3D object 150 to be selectively released and separated from the recess 130 of the first 3D object 105. Stated differently, the second 3D object 150 may be forcibly separated from the first 3D object at or via the element 160. In some examples, the entire element 160 may comprise partially fused build material, while in some examples just a portion of the element 160 may comprise partially fused build material to facilitate separation of the second 3D object from the first 3D object. It will be further understood that a retention arrangement (to releasably secure second 3D object 150) may comprise several elements, like element 160, or may comprise elements having shapes and/or sizes different from element 160. Moreover, such retention arrangements may extend from, or form a portion of, walls or portions of recess 130 other than top wall 134 as shown in FIG. 2B. [0039] It will be further understood that the second 3D object 150 is not limited to any particular orientation within recess 130 of the first 3D object 150.

[0040] In some examples, the second 3D object 150 can be accessed at any time from first 3D object 105, and such access and retrieval of the second 3D object 150 does not depend on breakage, end of useful life, etc. regarding the first 3D object 105.

[0041] FIG. 3 is a diagram 201 schematically representing an example device 200 to additively manufacture a single 3D assembly including a first 3D object at least partially containing a second 3D object, such as provided via the examples previously described in association with at least FIGS. 1-2B and/or later described in association with at least FIGS. 4A-10. Accordingly, the device 200 in FIG. 3 may comprise one example implementation of the arrangement 50 in FIG. 1 and/or comprise at least some of substantially the same features and attributes for additively manufacturing a 3D object as previously described in association with FIGS. 1-2B.

[0042] As shown in FIG. 3, in some examples, the device 200 comprises a material distributor 250 and a fluid dispenser 258. The material distributor 250 is arranged to dispense a build material layer-by-layer onto a build pad 242 to additively form the 3D object 280. Once formed, the 3D object 280 may be separated from the build pad 242. It will be understood that a 3D object of any shape and any size can be manufactured, and the object 280 depicted in FIG. 3 provides just one example shape and size of a 3D object. In some instances device 200 may sometimes be referred to as a 3D printer. Accordingly, the build pad 242 may sometimes be referred to as a print bed or a receiving surface.

[0043] It will be understood that the material distributor 250 may be implemented via a variety of electromechanical or mechanical mechanisms, such as doctor blades, slot dies, extruders, and/or other structures suitable to spread, deposit, and/or otherwise form a coating of the build material in a generally uniform layer relative to the build pad 242 or relative to a previously deposited layer of build material.

[0044] In some examples, the material distributor 250 has a length (L1) at least generally matching an entire length (L1) of the build pad 242, such that the material distributor 250 is capable of coating the entire build pad 242 with a layer 282A of build material in a single pass as the material distributor 250 travels the width (W1) of the build pad 242. In some examples, the material distributor 250 can selectively deposit layers of material in lengths and patterns less than a full length of the material distributor 250. In some examples, the material distributor 250 may coat the build pad 242 with a layer 282A of build material(s) using multiple passes instead of a single pass. [0045] It will be further understood that a 3D object additively formed via device 200 may have a width and/or a length less than a width (W1) and/or length (L1) of the build pad 242.

[0046] In some examples, the material distributor 250 moves in a first orientation (represented by directional arrow F) while the fluid dispenser 258 moves in a second orientation (represented by directional arrow S) generally perpendicular to the first orientation. In some examples, the material distributor 250 can deposit material in each pass of a back-and-forth travel path along the first orientation while the fluid dispenser 258 can deposit fluid agents in each pass of a back-and-forth travel path along the second orientation. In at least some examples, one pass is completed by the material distributor 250, followed by a pass of the fluid dispenser 258 before a second pass of the material distributor 250 is initiated, and so on.

[0047] In some examples, the material distributor 250 and the fluid dispenser 258 can be arranged to move in the same orientation, either the first orientation (F) or the second orientation (S). In some such examples, the material distributor 250 and the fluid dispenser 258 may be supported and moved via a single carriage while in some such examples, the material distributor 250 and dispenser 258 may be supported and moved via separate, independent carriages.

[0048] In some examples, the build material used to generally form the 3D object comprises a polymer material. In some examples, the polymer material comprises a polyamide material. Flowever, a broad range of polymer materials (or their combinations) may be employed as the build material. In some examples, the build material may comprise a ceramic material. In some examples, the build material may take the form of a powder while in some examples, the build material may take a non-powder form, such as liquid or filament. Regardless of the particular form, at least some examples of the build material is suitable for spreading, depositing, extruding, flowing, etc. in a form to produce layers (via material distributor 250) additively relative to build pad 242 and/or relative to previously formed first layers of the build material. [0049] In some examples, the fluid dispenser 258 shown in FIG. 3 comprises a printing mechanism, such as an array of printheads, each including a plurality of individually addressable nozzles for selectively ejecting fluid agents onto a layer of build material. Accordingly, in some examples, the fluid dispenser 258 may sometimes be referred to as an addressable fluid ejection array. In some examples, the fluid dispenser 258 may eject individual droplets having a volume on the order of ones of picoliters or on the order of ones of nanoliters.

[0050] In some examples, fluid dispenser 258 comprises a thermal inkjet (TIJ) array. In some examples, fluid dispenser 258 may comprise a piezoelectric inkjet (PIJ) array or other technologies such as aerosol jetting, anyone of which can precisely, selectively deposit a small volume of fluid. In some examples, fluid dispenser 258 may comprise continuous inkjet technology.

[0051] In some examples, the fluid dispenser 258 selective dispenses droplets on a voxel-by-voxel basis. In one sense a voxel may be understood as a unit of volume in a three-dimensional space. In some examples, a resolution of 1200 voxels per inch in the x-y plane is implemented via fluid dispenser 258. In some examples, a voxel may have a height H2 (or thickness) of about 100 microns, although a height of the voxel may fall between about 80 microns and about 100 microns. However, in some examples, a height of a voxel may fall outside the range of about 80 to about 100 microns. FIG. 3 also illustrates the fully formed 3D object 280 having a height H1.

[0052] In some examples, the height (H2) of the voxel may correspond to a thickness of one layer (e.g. 282A) of the build material.

[0053] In some examples, the fluid dispenser 258 has a width (W1) at least generally matching an entire width (W1) of the build pad 242, and therefore may sometimes be referred to as providing page-wide manufacturing (e.g. page wide printing). In such examples, via this arrangement the fluid dispenser 258 can deposit fluid agents onto the entire receiving surface in a single pass as the fluid dispenser 258 travels the length (L1) of the build pad 242. In some examples, the fluid dispenser 258 may deposit fluid agents onto a given layer of material using multiple passes instead of a single pass. [0054] In some examples, fluid dispenser 258 may comprise, or be in fluid communication with, an array of reservoirs to contain various fluid agents 262. In some examples, the array of reservoirs may comprise a fluid supply 215. In some examples, the fluid supply 215 comprises reservoirs to hold various fluids, such as a carrier (e.g. ink flux) by which various agents may be applied in a fluidic form.

[0055] In some examples, at least some of the fluid agents 262 may comprise a fusing agent, a color agent, detailing agent, etc. to enhance formation of each layer 282A of build material. In particular, upon application onto the build material at selectable positions via the fluid dispenser 258, the respective fusing agent and/or detailing agent may diffuse, saturate, and/or blend into the respective layer of the build material at the selectable positions. As noted elsewhere, a volume and/or location of application of the fusing agent and/or detailing agent on particular portions of the build material may be used to selectively control a degree of fusion (e.g. solidification).

[0056] As further shown in FIG. 3, in some examples, the at least partially formed 3D object 280 on build pad 242 comprises a first portion 271 A and a second portion 271 B with dashed line 273 representing a boundary between the first portion 271 A and the second portion 271 B. The 3D object 280 may have an exterior side surface 288.

[0057] During formation of a desired number of layers 282A of the build material, in some examples the fluid dispenser 258 may selectively dispense droplets of fluid agent(s) 262 at some first selectable voxel locations 274 of at least some respective layers 282A to at least partially define the first portion 271 A of the 3D object. It will be understood that a group 272 of first selectable voxel locations 274, or multiple different groups 272 of first selectable voxel locations 274 may be selected in any position, any size, any shape, and/or combination of shapes. [0058] In some examples, the at least some first selectable voxel locations 274 may correspond to an entire layer 282A of a 3D object or just a portion of a layer 282A. Meanwhile, in some examples, the 3D object may comprise a part of a larger object. In some examples, each first selectable voxel location 274 corresponds to a single voxel. [0059] As further shown in FIG. 3, in some examples device 200 comprises an energy source 210 for applying energy (e.g. irradiating) to the deposited build materials, fluid agents (e.g. fusing agent, detailing agent, etc.) to cause heating of the material, which in turn results in the fusing of particles of the material relative to each other, with such fusing occurring via melting, sintering, etc. In portions of the 3D object in which full solidification is desired, such as for structural purposes, then a full volume of the respective fusing agents and/or detailing agents are applied to those portions of the 3D object. However, as noted elsewhere previously, in portions of the 3D object for which it is desired to form a release boundary between a first 3D object and a second 3D object contained within the first 3D object (or form a latent fracturable portion within a first 3D object), then a lower volume of the respective fusing agent(s) is to be applied to create partial fusion instead of full fusion. Moreover, adjustments may be made to a volume of applied detailing agent(s).

[0060] After application of the radiation from energy source 210, a layer 282A of build material is formed and additional layers 282A of build material may be formed in a similar manner as represented in FIG. 3. In view of the foregoing examples, it will be understood that any given formed layer 282A of build material may include at least some portions which are unfused, partially fused, and/or fully fused in order to achieve the objectives regarding containment of the second 3D object (e.g. 150), releasable securement of the second 3D object (e.g. 150), facilitating selective fracturability of the first 3D object (e.g. 150), release boundaries, and related aspects described throughout the various examples of the present disclosure.

[0061] In some examples, the energy source 210 may comprise a gas discharge illuminant, such as but not limited to a Halogen lamp. In some examples, the energy source 210 may comprise multiple energy sources. As previously noted, energy source 210 may be stationary or mobile and may operate in a single flash or multiple flash mode.

[0062] As shown in FIG. 3, in some examples device 200 may comprise a control portion 217 to direct operations of device 200. In some examples, control portion 217 may be implemented via at least some of substantially the same features and attributes as control portion 800, as later described in association with at least FIG. 9B.

[0063] In some examples the device 200 in FIG. 3 can be used to additively form a 3D object via a powder bed-based process, such as MultiJet Fusion (MJF) process (available from HP, Inc.). It will be understood that in some examples other additive manufacturing techniques (e.g. Fused Deposition Modeling (FDM), LaserProFusion, Selective Laser Sintering (SLS), Selective Laser Melting (SLM), 3D binder jetting, Electron Beam Melting (EBM), ProJet Fusion, etc.) may be used for form a 3D object. Accordingly, in such arrangements, the examples of the present disclosure may be implemented according to the particular build materials, application techniques, curing techniques, etc. associated with each particular modality of manufacturing.

[0064] FIG. 4A is diagram 300 including an isometric view schematically representing an example single 3D assembly 401 of a first 3D object containing a second 3D object therein. FIG. 4B is a sectional view of the single 3D assembly 401 as taken along lines 4B — 4B of FIG. 4A. In some examples, the single 3D assembly 401 may be additively manufactured according to at least some of substantially the same features and attributes as previously described in association with at least FIGS. 1-3.

[0065] As shown in FIG. 4A, the 3D assembly 301 comprises at least some of substantially the same features and attributes as single 3D assembly 101 in FIGS. 2A-2B, except with cavity 138 being completely sealingly closed via element 320. In some examples, element 320 may be incorporated into, and form part of, bottom portion 106B of the first 3D object. In some such examples, the element 320 is integrally formed as part of bottom portion 106B, and therefore element 320 would be seamlessly integrated into rest of bottom portion 106B, which is visible in FIGS. 4A-4B.

[0066] However, as shown in FIG. 4B, in some examples, the ends (e.g. outer edge) of element 320 are joined to side walls 131 of first 3D object at seams 333A, 333B. In some examples, the seams 333A, 333B are formed of partially fused build material to facilitate removal of element 320 and/or destruction of at least bottom portion 106B of first 3D object, with the partially fused material forming seams 333A, 333B being generally weaker than nearby fully fused build material. In such instances, the element 320 may sometimes be referred to as a removable cover. Moreover, in some examples, the element 320 may have different shapes and/or sizes than shown in FIGS. 4A-4B, and also may be located at different portions of first 3D object 301 than shown in FIGS. 4A-4B. [0067] In addition, in some examples, the first 3D object 305 may comprise multiple different cavities 130 located among different portions of the first 3D 305 object, which may be particularly helpful when the first 3D object 305 may comprise a more complex shape with different portions diverging from each other and a large number of second 3D objects 150 are to be contained within the first 3D object 305.

[0068] In some examples in which the first 3D object 305 comprises a cover (e.g. element 320) to sealingly close the cavity, the element 160 may be omitted in favor of a different type of retention arrangement to releasably secure the second 3D object(s) 150 relative to the first 3D object 305. For instance, in FIG. 4C, a portion 470 forming part of bottom portion 106B acts to sealingly close cavity 130. In a manner similar to the above-described element 320 (e.g. cover), the portion 470 may seamlessly form part of bottom portion 106B or in some examples, portion 470 may be connected to the rest of first 3D object 355 via seams, like seams 333A, 333B in FIG. 4B. Regardless of the manner in which the cavity 130 is sealingly closed as part of additively manufacturing the 3D assembly 351 of FIG. 4C, in some examples the recess 130 of the first 3D object 355 may be filled with (e.g. formed as) an unfused build material 389, such as a free powder build material, which surrounds at least one second 3D object 150 within the cavity 138 defined by recess 130. The unfused build material acts as a retention arrangement to help releasably secure the second 3D object 150 within the cavity 138 (and relative to the recess 130) of the first 3D object 355. As previously noted, the recess 130 may sometimes be referred to as an interior portion of the first 3D object.

[0069] Upon removing the portion 470, and/or otherwise destructing pertinent portions of the first 3D object 355, in order to access the second 3D object(s) 150 from cavity 138, the free build material 389 will become separated (or separable) from the recess 130 and separable from the second 3D object(s) 150.

[0070] As further shown in FIG. 4C, in some examples the first 3D object 355 may contain multiple second 3D objects 150. In some such examples, all of the multiple second 3D objects 150 are identical such as shown in FIG. 4C, while in some examples, at least some of the second 3D objects 150 are different from each other. Such differences may relate to size, shape, and/or type. Accordingly, in some examples, some of the multiple second 3D objects 150 may have completely different purposes, sizes, shapes, etc. from each other. With regard to the examples of providing replacement parts, the multiple second 3D objects 150 may comprise different types of replacement parts, different sizes of the same type of replacement part, multiple instances of the same type and size of replacement part, etc.

[0071] Moreover, in some such examples of multiple second 3D objects, the unfused build material acting as a filler 389 can still serve as a retention arrangement in which the unfused build material surrounds each separate second 3D object 150 (which are spaced from each other) and is also in contact with the walls (134, 132) of the recess 130 to effectively immobilize the multiple second 3D objects within cavity 138.

[0072] It will be understood that in some examples, some voxel locations (e.g. 274) of the unfused build material 389 depicted in FIG. 4C and present throughout the cavity 138 can be partially fused to lend at least some stability to the build material 389 serving as a retention arrangement between the first 3D object and the multiple second 3D objects 150. In some such examples, the selected locations at which build material 389 is partially fused may be relatively weak and fracturable-at-will when it is desired to retrieve the second 3D objects 150 from cavity 138.

[0073] In some examples, a retention arrangement (to releasably secure the second 3D object 150 relative to first 3D object 355) may comprise a combination of different elements, such as a combination of some elements like element 160 and the unfused build material 389 within cavity 138, which work together along with recess 130 to retain the second 3D object until it is desired to access and retrieve it from the first 3D object.

[0074] FIGS. 5A-5B are diagrams which schematically represent a 3D assembly 401 of a first 3D object 405 and second 3D object 150 which comprise at least some of substantially the same features and attributes as the previously described example associated with at least FIGS. 4A-4B, except for including a port 442 in bottom portion 106B of first 3D object 405, among other differences. As shown in FIGS. 5A-5B, in a manner similar to the examples shown in FIGS. 2A-2B, 4A-4B, an element 160 may serve as a retention arrangement which releasably secures the second 3D object 150 relative to the recess 130 (e.g. interior portion) of the first 3D object 405. As further shown in FIGS. 5A-5B, the first 3D object 405 may comprise element 440 of bottom portion 106B which covers the entirety of the cavity 138 of first 3D object 405, except for port 442 defined within element 440. It will be understood that during additive manufacture of single assembly 401 , the cavity 138 of recess 130 may built as (i.e. filled with) unfused build material as part of the normal layer-by-layer building process. After the complete formation of single assembly 3D 401 , the unfused build material may be removed from cavity 138 because it no longer is providing a function and also may add extra, unnecessary weight to the single assembly 401. In addition, removal of the unnecessary unfused build material also provides a clean, debris free experience for those handling the respective single 3D assembly 401.

[0075] With regard to the element 440 covering the cavity 138, in order to account for the presence of port 442, the element 440 may be said to substantially cover the opening 172 of cavity 138. In some examples, the term “substantially covers” corresponds to at least about 90 percent coverage, 91 percent coverage, and so on up to at least 99 percent coverage of the opening (e.g. 172 in FIG. 2B) provided that port 442 remains large enough for a free build material (e.g. 389 in FIG. 4C) to be removed (e.g. drained, suctioned out, etc.) from the cavity 138 after formation of the single assembly 401 is completed. [0076] In order to access the second 3D object 150 at a desired time, the element 440 may be at least partially destroyed and/or larger portions of the first 3D object 405 may be broken to enable removal of the second 3D object 150 from cavity 138. Moreover, in some examples, the element 440 may comprise at least some of substantially the same features and attributes as one of the examples of a removable cover 320 described in association with FIG. 4B in which seams 333A, 333B are present to facilitate removal of element 440 from the first 3D object 405 to permit access to second 3D object 150 without destructing other portions of the first 3D object 405.

[0077] FIGS. 6A-6B schematically represent a 3D assembly 451 comprising at least some of substantially the same features and attributes as the examples previously described in association with at least FIGS. 1-5B, except with a bottom portion 106B of the first 3D object 455 comprising door(s) 439A, 439B as shown in FIGS. 6A-6B. In some examples, doors 439A, 439B are removable, while in some examples, doors 439A, 439B may be openable and closable as represented via directional arrows E. In one aspect, FIGS. 6A-6B include indicator 426 to schematically represent at point at which the respective doors 439A, 439B releasably contact each other.

[0078] In either case, the doors 439A, 439B provide an access path to retrieve the second 3D object 150 from the cavity 138 of first 3D object 455 without destructing other portions of the first 3D object 455. In some examples, the doors 439A, 439B are added after completion of additive manufacturing of the single assembly 451.

[0079] Flowever, in some examples, the doors 439A, 439B, may be formed as part of the layer-by-layer, additive manufacturing of the 3D assembly 451 and in which seams 437A, 437B are formed. In some such examples, the seams 437A, 437B may act as a living hinge to permit rotational movement (arrows E) of doors 439A, 439B, such that doors 439A, 439B may be opened and closed. In some such examples, the seams 437A, 437B may comprise partially fused build material and may be formed via applying a selectable volume of fusing agent(s) and/or detailing agent(s) in a combination (or separately) which lends flexibility and resilience to the seams 437A, 437B. [0080] In a manner similar to that previously described in association with at least FIGS. 5A-5B, unfused build material (e.g. 389 in FIG. 4C) which was present in cavity 138 during the layer-by-layer, additive manufacturing of single assembly 451 can be removed by opening doors 439A, 439B.

[0081] Moreover, as in some of the previously-described examples, the doors 439A, 439B may provide an access pathway to retrieve the second 3D object 455 at a desired time without involving destruction of portions of the first 3D object 405.

[0082] FIG. 7A is a diagram including a side sectional view schematically representing an example 3D assembly 551 including a second 3D object 575 contained within an interior portion of an example first three-dimensional object 565. In some examples, the 3D assembly 551 may be additively manufactured in a manner comprising at least some of substantially the same features and attributes as previously described in association with at least FIGS. 1-6B.

[0083] As shown in FIG. 7A, the second 3D object 575 is completely contained within (e.g. completely embedded within) the first 3D object 565 with a first release boundary 579 interposed between an exterior surface portion 577 of the second 3D object 575 and an interior surface portion 567 of the first 3D object 565. In some examples, the first release boundary 579 comprises at least one of unfused build material or partially fused build material, which facilitates separation of the first and second 3D objects 565, 575 upon at least partial destruction of the first 3D object 565 to enable access to the second 3D object 575. In some examples, the first release boundary 579 may sometimes be referred to as a retention arrangement, at least to the extent that the first release boundary 579 may, in some examples, may help retain the second 3D object 575 relative to the first 3D object 565 until it is desired to access and separate the second 3D object 575 from the first 3D object 565.

[0084] While FIG. 7A depicts the first 3D object 565 as a cuboid shape (which is rectangular in cross-section) and the second 3D object 575 as a sphere (which is circular in cross-section), it will be understood that the first 3D object 565 and/or the second 3D object 575 may comprise a wide variety of simple or complex shapes and/or sizes other than those shown in FIG. 7A. [0085] As previously noted in the context of the previously-described examples, each of the respective first and second 3D objects 565, 575 may comprise a functional article, an ornamental article, or may comprise an article comprising both functional and ornamental attributes. Moreover, one of the respective first and second 3D objects 565, 575 may have a purpose or function related to the other respective one of the 3D objects 565, 575, while in some examples, each of the respective first and second 3D objects 565, 575 may have a purpose or function completely unrelated to each other.

[0086] FIG. 7B is sectional view schematically representing an example 3D assembly 581 comprising substantially the same features and attributes as 3D assembly 551 in FIG. 7A, except with 3D assembly 581 further comprising a third 3D object 585 nested within the second 3D object 575. Accordingly, as shown in FIG. 7B, the third 3D object 585 is completely contained within (e.g. completely embedded within) the second 3D object 575 with a second release boundary 589 interposed between an exterior surface portion 587 of the third 3D object 585 and an interior surface portion 588 of the second 3D object 575. In a manner similar to the first release boundary 579, in some examples, the second release boundary 589 comprises at least one of unfused build material or partially fused build material, which facilitates separation and deployment of the third 3D object 585 upon at least partial destruction of the second 3D object 575, which enable access to the third 3D object 585.

[0087] While FIG. 7A depicts the third 3D object 585 as a pentagon shape (as seen in cross-section), it will be understood that the third 3D object 585 may comprise a wide variety of simple or complex shapes and/or sizes other than that shown in FIG. 7B.

[0088] As previously noted in the context of the previously-described examples, the third 3D object 585 may comprise a functional article, an ornamental article, or may comprise an article comprising both functional and ornamental attributes. [0089] With regard to the examples of at least FIGS. 7A-7B, it will be understood that such nesting of multiple 3D objects within each other is not limited to the number of respective 3D objects shown in FIGS. 7A-7B. For example, more than one second 3D object 575 may be contained within the first 3D object 565 with the multiple second 3D objects 575 being separate from each other and each having their own release boundary (like boundary 579) relative to the first 3D object 565. In such arrangements, the multiple second 3D objects 575 may or may not have the same shapes, sizes, purposes, etc. as each other. Similarly, more than one third 3D object 575 may be contained within the second 3D object 555 with the multiple third 3D objects 585 being separate from each other and each having their own release boundary (like boundary 589) relative to the second 3D object 575. The multiple second 3D objects 575 may or may not have the same shapes, sizes, purposes, etc. as each other.

[0090] Moreover, with regard to the nesting of multiple 3D objects 585, 575, 565 within each other as shown in FIGS. 7A-7B, it will understood that further nesting relationships may be implemented, such that a fourth 3D object, fifth 3D object, and so on may be in a similar nesting relationship.

[0091] FIG. 8A is a diagram 600 including a sectional view schematically representing an example single 3D assembly 601 including a first 3D object 615 containing an example second 3D object 625. In some examples, the example single 3D assembly 601 may be additively manufactured via at least some of substantially the same features and attributes as previously described in association with at least FIG. 3 and/or at least FIGS. 1-2B and 4A-7B.

[0092] As shown in FIG. 8A, the example first 3D object 615 comprises a volume and a shape large enough to completely contain the example second 3D object 625. In a manner similar to the examples in FIGS. 7A-7B, a first release boundary 627A is interposed between the first 3D object 615 and the second 3D object 625. In addition, a second release boundary 627B may be interposed between the second 3D object 625 and a third 3D object 629. In some examples, the third 3D object 629 may comprise a discardable element or may comprise a replacement part for the machine in which first 3D object 615 resides or for another separate machine.

[0093] As further shown in FIGS. 8A-8B, in some examples the second 3D object 625 may comprise a functional part, such as a gear. Moreover, in the particular example shown, the first 3D object 615 may comprise a part of a larger assembly, such as a machine in which first 3D object 615 comprises a functional part, for example. In some such examples, the first 3D object 615 may comprise a load-bearing part of a machine, such as represented via the directional force arrow 619 (Load) in FIG. 8A.

[0094] As previously noted with other examples of the present disclosure, upon the first 3D object 615 exceeding its useful life, breaking, etc. or upon a desire to obtain the second 3D object 625 (e.g. because it has a higher priority), the first 3D object 615 may be destructed to a point at which the embedded second 3D object 625 may be accessed and separated from the first 3D object 615 to standalone as shown in FIG. 8B. Upon the fracture of the first 3D object of FIG. 8A , the second 3D object 625 becomes independent of, and separate from, the first 3D object 615 as shown in FIG. 8B such that the second 3D object 625 may be deployed for its designated purpose. In a manner similar to the previously- described examples of the present disclosure, the first release boundary 627A may facilitate such access and separation.

[0095] As part of separating the second 3D object 625 out from the first 3D object 62, via manipulation of the second release boundary 627B a third 3D object 629 (FIG. 8A) is also removed from the interior of second 3D object 625 such that the second 3D object 625 (including hollow center 645) is available to be deployed for its intended purpose.

[0096] As further shown in FIG. 8A, in some examples the 3D assembly 601 may be additively manufactured such that the first 3D object 615 also comprises a latent fracturable portion 626 extending within the first 3D object 615 to facilitate fracture of the first 3D object 615 in a desired manner and at a desired point in time. In some examples, the latent fracturable portion 626 comprises at least one of unfused build material and partially fused build material such that the latent fracturable portion 626 is generally weaker than the fully fused build material of the portions of first 3D object 615 surrounding the latent fracturable portion 626. In some such examples, the latent fracturable portion 626 extends in an orientation (line T) which is generally perpendicular to an orientation (line C) through which a load 629 is expected to act on the first 3D object 615. Via this perpendicular arrangement, the latent fracturable release portion 626 is generally unaffected by the applied compressive load 629 such that the first 3D object 615 will not break prematurely solely because of the existence of the latent fracturable portion 626. While the latent fracturable portion 626 is shown in FIG. 8A as an elongate element which extends in a straight line, it will be understood that the latent fracturable portion can take a wide variety of shapes, sizes, locations, orientations (e.g. perpendicular, non-perpendicular), etc. in order to facilitate selective destruction of the first 3D object at a desired point in time.

[0097] In some such examples, the latent fracturable portion 626 may be distinguished from other release boundaries, such as release boundary 627A at least because the latent fracturable portion 626 is not directly interposed between the first and second 3D objects 615, 625. However, as shown in some examples, as shown in FIG. 8A, the latent fracturable portion 626 may intersect with (i.e. have continuity with) the first release boundary 627A (as shown via arrow F) to further facilitate fracture of the first 3D object 615 at a desired time and upon intentional manipulation of the first 3D object 615 to cause such fracture.

[0098] FIG. 9A is a block diagram schematically representing an example object formation engine 700. In some examples, the object formation engine 700 may form part of a control portion 800, as later described in association with at least FIG. 9B, such as but not limited to comprising at least part of the instructions 811. In some examples, the object formation engine 700 may be used to implement at least some of the various example devices and/or example methods of the present disclosure as previously described in association with FIGS. 1-8 and/or as later described in association with FIGS. 9B-10. In some examples, the object formation engine 700 (FIG. 9A) and/or control portion 800 (FIG. 9B) may form part of, and/or be in communication with, an object formation device, such as the additive manufacturing device 200. Accordingly, in some examples, at least some aspects of control portion 800 may comprise one example implementation of the control portion 217 of device 200 in FIG. 3. [0099] As shown in FIG. 9A, in some examples the object formation engine 700 may comprise a material distributor engine 702, fluid dispenser engine 704, and energy source engine 706. [00100] As shown in FIG. 9A, in some examples the material distributor engine 702 controls distribution of layers of build material relative to build pad (e.g. 242 in FIG. 4) and/or relative to previously deposited layers of build material. In some examples, the material distributor engine 702 comprises a material parameter to specify which build material(s) and the quantity of such build material which can be used to additively form a body of the 3D object. In some examples, these materials are deposited via build material distributor 250 of device 200 (FIG. 4).

[00101] In some examples, the material controlled via the material distributor engine 702 may comprise polymers, ceramics, etc. having sufficient strength, formability, toughness, etc. for the intended use of the 3D object with at least some example materials being previously described in association with at least FIG. 3.

[00102] As shown in FIG. 9A, in some examples the fluid dispenser engine 704 may specify which fluid agents are to be selectively deposited onto a layer (or portions of a layer) of build material on a voxel-by-voxel basis, as previously described in association with at least FIG. 3. In some examples, such agents are deposited via fluid dispenser 258 (FIG. 3). In some examples, the fluid dispenser engine 704 may comprise a carrier function and an agent function to apply fluid agents, such as the carrier, fusing, detailing, etc. as previously described in association with at least FIG. 3.

[00103] In particular, via the fluid dispenser engine 704, application of a selectable volume (and location) of a fusing agent and/or detailing agent may be used to selectably control a degree of fusion at selectable voxel locations (274 in FIG. 3). In some such examples, such control may be used to form lattice structures, networks of interconnected elements, separable portions, release boundaries, etc. as described throughout various examples of the present disclosure. In some examples, fluid dispenser engine 704 may specify a number of fluid application channels, volume of fluid to be applied, during which pass the particular fluid channel is active, etc.

[00104] In some examples, the energy source engine 706 of object formation engine 700 is to control operations of at least one energy source (e.g. 210 in FIG. 3). In some examples, the energy source engine 706 may control an amount of time that energy (e.g. radiation) from the energy source 210 (FIG. 3) is emitted toward the material, agents, etc. on a layer of build material, with a resulting degree of fusion depending on a volume (and location) of fusing agent(s) and/or detailing agent(s) applied at particular voxel locations (274 in FIG. 3). In some examples, the energy source 706 may irradiate the targeted layer (of the 3D object under formation) in a single flash or in multiple flashes. In some examples, the energy source may remain stationary (i.e. static) or may be mobile. In either case, during such irradiation, the energy source engine 706 controls the intensity, volume, and/or rate of irradiation.

[00105] As further shown in FIG. 9A, in some examples, the object formation engine 700 comprise a lattice formation engine 730, which is to control additive formation of a 3D assembly including a first 3D object which at least partially contains a second 3D object (and related variations), as previously described in various examples throughout the present disclosure. In some examples, in cooperation with the fluid dispenser engine 704, the containment engine 730 may provide partial control over a volume and location at which a fusing agent(s) and/or detailing agent(s) are deposited onto a layer of build material, which in turn provides control over formation of a cavity, release boundary, retention arrangement, etc. as further described below. In one aspect, the relative volume of the fusing agent(s) and/or detailing agent(s) deposited to a particular voxel location (e.g. 274 in FIG. 3) determines a degree of fusion of the particular voxel location, as previously described in association with at least FIG. 3. In particular, in the absence of a fusing agent applied to a particular voxel location and upon application of radiation per energy source (e.g. 210 in FIG. 3), no fusion will take place for the particular voxel location(s) 274 (FIG. 3). This arrangement will result in unfused build material (i.e. free powder build material) at the particular voxel location(s) 274. On the other hand, upon depositing a selectable volume of at least fusing agent(s) and/or detailing agent(s) to a particular voxel location(s) 274, one can control a degree of fusion of the build material at the particular voxel location(s) 274. Via this arrangement, the particular voxel location(s) 274 may become at least partially fused and in some instances, fully fused.

[00106] As shown in FIG. 9A, in some examples, the containment engine

730 comprises a cavity engine 731 and a retention engine 750, along with a quantity parameter 758 and a nesting parameter 759.

[00107] As shown in FIG. 9A, in some examples, the cavity engine 731 comprises a location parameter 732, a volume parameter 734, a shape parameter 736, an open parameter 738 and/or a closed parameter 739.

[00108] In some examples, in order to additively manufacture a first 3D object (of a 3D assembly) having a cavity (e.g. FIGS. 2A-2B, 4A-7B) to at least partially contain a second 3D object, such additive manufacturing may be implemented to have a selectable location (parameter 732), volume (parameter 734), and/or shape (parameter 736) within a first 3D object (e.g. 105 in FIG. 2A- 2B). In some such examples, the volume can be specified as an absolute volume or as a relative volume of the first 3D object. Similarly, to the extent that the second 3D object(s) also comprise a cavity (defined by a recess) to at least partially contain a third 3D object and so on, these same parameters may be used to determine a respective location, volume, shape, etc. of the second 3D object and further contained 3D objects.

[00109] In some examples, the selectable location (732) may comprise specifying a location within the particular 3D object (e.g. first, second, etc.) at which the cavity will be formed, and may be expressed via three-dimensional (x, y, z) coordinates of the boundaries of the cavity.

[00110] In some examples, the cavity engine 731 may comprise an open parameter (738) to additively form an open cavity, i.e. one that is not closed with a cover or wall of the 3D object being formed. Via parameter 738, a size and/or shape of such opening of the cavity may be selected. One example implementation of an open cavity is previously described in association with at least FIGS. 2A-2B.

[00111] In some examples, via a closed parameter (739), the cavity engine

731 is to control additive manufacture of a closed cavity, such as the example previously described in association with at least FIGS. 4A-4C, 6A-6B, 7A-7B. In some instances, a cavity may be closed via a cover (e.g. 4A-4B) or openable doors (e.g. FIGS. 6A-6B). In some examples, via the closed parameter 739, a wall or cover for the cavity may be provided in a manner in which the cavity is substantially closed, except for a small opening, such as in the previously described example(s) in association with FIGS. 5A-5B.

[00112] In some examples, the object formation engine 700 comprises a retention engine 750, which is to control formation and placement of a retention arrangement to retain a second 3D object relative to a first 3D object, as previously described throughout various examples of the present disclosure. For instance, in some examples, via parameter 732, a retention arrangement can be formed as an element which extends between a second 3D object and the first 3D object, such as element 160, which is previously described in association with at least FIGS. 2A-2B, 4A-4B, 5A-5B, and 6A-6B. As previously noted, such an element can take many forms, sizes, shapes, locations other than shown for element 160 in those FIGS.

[00113] In some examples, retention engine 750 may comprise a fill parameter 754 by which an unfused build parameter may act to fill all (or portion of) a cavity (e.g. 138) to help retain a second 3D object relative to an interior portion (e.g. recess 130) of a first 3D object. One example implementation of the fill parameter 754 is previously described in association with at least FIG. 4C, wherein unfused build material 389 acted as fill to retain the second 3D objects 150 relative to recess 130 of first 3D object 355. As previously noted, in some examples, some of the fill material may comprise partially fused build material and/or fully fused build material to provide at least some minimal stability to the fill structure.

[00114] In some examples, the retention engine 750 may comprise a boundary parameter 756 to control the characteristics (location, shape, size etc.) by which a release boundary may to help retain a second 3D object relative to an interior portion of a first 3D object. One example implementation of the boundary parameter 756 is previously described in association with at least FIGS. 7A-7B, 8A-8B, wherein unfused build material or partially fused build material may act to form a release boundary between respective first and second 3D object. The release boundary retains the second 3D object in relation to the first 3D object, while also providing a mechanism to readily separate the second 3D object at an appropriate time and manner when it is desired to retrieve the second 3D object from the first 3D object.

[00115] In some examples, the retention engine 750 may comprise a latent parameter 757 to control the characteristics (location, shape, size etc.) by which a latent fracturable portion may to help selectively access a second 3D object relative to an interior portion of a first 3D object. One example implementation of the latent fracturable portion 757 was previously described in association with at least FIGS. 8A-8B, wherein unfused build material or partially fused build material acts to form a latent fracturable portion (e.g. 626) within a first 3D object. The latent fracturable portion 626 provides a mechanism to readily separate the second 3D object at an appropriate time and manner when it is desired to retrieve the second 3D object from the first 3D object.

[00116] In some examples, the object formation engine 700 comprises an inventory engine 770 to track and/or control an inventory and availability of the various 3D assemblies, first 3D objects, second 3D objects, etc. In some examples, the inventory engine 770 is to implement such tracking and/or control according to the various types (parameter 772), quantities (parameter 774), and/or locations (parameter 776) of the various first 3D assemblies, first 3D objects, second 3D objects, etc. In some examples, such tracking and/or control may be at least partially implemented in association with the user interface 820 in FIG. 9C.

[00117] It will be understood that various functions and parameters of object formation engine 700 may be operated interdependently and/or in coordination with each other, in at least some examples.

[00118] FIG. 9B is a block diagram schematically representing an example control portion 800. In some examples, control portion 800 provides one example implementation of a control portion (e.g. 217 in FIG. 4) forming a part of, implementing, and/or generally managing the example additive manufacturing devices, as well as the particular portions, components, material distributors, fluid supply, fluid dispensers, energy sources, control portion, instructions, engines, functions, parameters, and/or methods, as described throughout examples of the present disclosure in association with FIGS. 1-8B and 9B-10. In some examples, control portion 800 includes a controller 802 and a memory 810. In general terms, controller 802 of control portion 800 comprises at least one processor 804 and associated memories. The controller 802 is electrically couplable to, and in communication with, memory 810 to generate control signals to direct operation of at least some the object formation devices, various portions and elements of the example additive manufacturing devices, as well as the particular portions, components, material distributors, fluid supply, fluid dispensers, energy sources, control portion, instructions, engines, functions, parameters, and/or methods, as described throughout examples of the present disclosure. In some examples, these generated control signals include, but are not limited to, employing instructions 811 stored in memory 810 to at least direct and manage additive manufacturing of 3D objects in the manner described in at least some examples of the present disclosure. In some instances, the controller 802 or control portion 800 may sometimes be referred to as being programmed to perform the above-identified actions, functions, etc. In some examples, at least some of the stored instructions 811 are implemented as a, or may be referred to as, a 3D print engine, an object formation engine, and the like, such as but not limited to the object formation engine 700 in FIG. 9A.

[00119] In response to or based upon commands received via a user interface (e.g. user interface 820 in FIG. 9C) and/or via machine readable instructions, controller 802 generates control signals as described above in accordance with at least some of the examples of the present disclosure. In some examples, controller 802 is embodied in a general purpose computing device while in some examples, controller 802 is incorporated into or associated with at least some of the additive manufacturing devices, as well as the particular portions, components, material distributors, fluid supply, fluid dispensers, energy sources, control portion, instructions, engines, functions, parameters, and/or methods, etc. as described throughout examples of the present disclosure. [00120] For purposes of this application, in reference to the controller 802, the term “processor” shall mean a presently developed or future developed processor (or processing resources) that executes machine readable instructions contained in a memory or that includes circuitry to perform computations. In some examples, execution of the machine readable instructions, such as those provided via memory 810 of control portion 800 cause the processor to perform the above-identified actions, such as operating controller 802 to implement the formation of 3D objects as a single 3D assembly in which a first 3D object may at least partially contain a second 3D object, as generally described in (or consistent with) at least some examples of the present disclosure. The machine readable instructions may be loaded in a random access memory (RAM) for execution by the processor from their stored location in a read only memory (ROM), a mass storage device, or some other persistent storage (e.g., non-transitory tangible medium or non-volatile tangible medium), as represented by memory 810. The machine readable instructions may include a sequence of instructions, a processor-executable machine learning model, or the like. In some examples, memory 810 comprises a computer readable tangible medium providing non-volatile storage of the machine readable instructions executable by a process of controller 802. In some examples, the computer readable tangible medium may sometimes be referred to as, and/or comprise at least a portion of, a computer program product. In other examples, hard wired circuitry may be used in place of or in combination with machine readable instructions to implement the functions described. For example, controller 802 may be embodied as part of at least one application-specific integrated circuit (ASIC), at least one field-programmable gate array (FPGA), and/or the like. In at least some examples, the controller 802 is not limited to any specific combination of hardware circuitry and machine readable instructions, nor limited to any particular source for the machine readable instructions executed by the controller 802.

[00121] In some examples, control portion 800 may be entirely implemented within or by a stand-alone device. [00122] In some examples, the control portion 800 may be partially implemented in one of the object formation devices and partially implemented in a computing resource separate from, and independent of, the object formation devices but in communication with the object formation devices. For instance, in some examples control portion 800 may be implemented via a server accessible via the cloud and/or other network pathways. In some examples, the control portion 800 may be distributed or apportioned among multiple devices or resources such as among a server, an object formation device, and/or a user interface.

[00123] In some examples, control portion 800 includes, and/or is in communication with, a user interface 820 as shown in FIG. 9C. In some examples, user interface 820 comprises a user interface or other display that provides for the simultaneous display, activation, and/or operation of at least some of the additive manufacturing devices, as well as the particular portions, components, material distributors, fluid supply, fluid dispensers, energy sources, control portion, instructions, engines, functions, parameters, and/or methods, etc., as described in association with FIGS. 1-9B and 10A-10. In some examples, at least some portions or aspects of the user interface 820 are provided via a graphical user interface (GUI), and may comprise a display 824 and input 822.

[00124] FIG. 10 is a flow diagram of an example method 900. In some examples, method 900 may be performed via at least some of the devices, components, material distributors, fluid supply, fluid dispensers, energy sources, instructions, control portions, engines, functions, parameters, and/or methods, etc. as previously described in association with at least FIGS. 1-9C. In some examples, method 900 may be performed via at least some of the devices, components, material distributors, fluid supply, fluid dispensers, energy sources, instructions, control portions, engines, functions, parameters, and/or methods, etc. other than those previously described in association with at least FIGS. 1- 9C.

[00125] As shown at 902 in FIG. 10, method 900 comprises additively manufacturing a 3D assembly including a first 3D object and a second 3D object, wherein the second 3D object is constrained, via a retention arrangement, relative to cavity of the first 3D object and the second 3D object is selectively removable from the first 3D object via forcible separation at the retention arrangement.

[00126] Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein.

Claims

1. A non-transitory machine-readable storage medium, encoded with instructions executable by a processor, comprising: instructions to generate data representing a three-dimensional object model to additively manufacture a three-dimensional assembly which comprises a first three-dimensional object and a second three-dimensional object, wherein the second three-dimensional object is at least partially contained within the first three-dimensional object, and is releasably secured relative to the first three- dimensional object, in a position to defer independent deployment of the second three-dimensional object.

2. The non-transitory machine-readable storage medium of claim 1 , wherein the instructions are to cause the at least partially containment of the second three-dimensional object, and the releasable securement of the second three- dimensional object, via a cavity of first three-dimensional object within which the second three-dimensional object is present and the cavity is open to the environment, wherein with the second three-dimensional object is accessible via the cavity without destruction of the first three-dimensional object.

3. The non-transitory machine-readable storage medium of claim 1 , wherein the instructions are to cause the at least partially containment of the second three-dimensional object, and the releasable securement of the second three- dimensional object, via a cavity of first three-dimensional object within which the second three-dimensional object is present and the cavity being at least one of: sealed closed, with the second three-dimensional object being accessible via at least partial destruction of the first three-dimensional object; and closable, with the second 3D object being accessible via a door.

4. The non-transitory machine readable medium of claim 1 , wherein the instructions are to implement the at least partial containment of the second three-dimensional object as the second three-dimensional object being embedded within an interior portion of the first three-dimensional object with a first release boundary defined between an exterior surface portion of the second three-dimensional object and an interior surface portion of the first three- dimensional object, with the first release boundary comprising at least one of unfused build material or partially fused build material.

5. The non-transitory machine readable medium of claim 4, wherein the instructions are to implement the additive manufacturing to include a third three- dimensional object embedded within the second three-dimensional object with a second release boundary defined between an exterior surface portion of the third three-dimensional object and an interior surface portion of the second three-dimensional object, with the second release boundary comprising at least one of unfused build material or partially fused build material.

6. The non-transitory machine readable medium of claim 1 , wherein the instructions are to additively manufacture the second three-dimensional object to be releasably securable relative to the first three-dimensional object via a latent fracturable portion between the respective first and second three- dimensional objects, which comprises at least one of unfused build material and partially fused build material.

7. The non-transitory machine readable medium of claim 1 , wherein the second three-dimensional object comprises a plurality of second three- dimensional objects.

8. The non-transitory machine readable medium of claim 7, wherein the instructions are to additively manufacture the 3D assembly with the first three- dimensional object comprising a closed cavity retaining unfused build material, which is to surround the respective second three-dimensional objects.

9. A print control portion comprising: a processor programmed to additively form a 3D structure which comprises a first 3D object and a second 3D object, wherein the second 3D object is at least partially enclosed within an interior portion of the first 3D object to defer use of the second 3D object apart from the first 3D object, wherein the second 3D object is selectively restrained relative to the first 3D object via a retention element at least partially formed of at least one of an unfused build material and a partially fused build material.

10. The print control portion of claim 9, wherein the print control portion is at least one of: in communication with a 3D printer; and incorporated as part of the 3D printer, wherein the 3D printer comprises: a build unit including a build platform; a build material distributor to distribute a build material on the build platform; a fluid dispenser to selectively apply at least one agent to the build material, the at least one agent comprising a detailing agent and a fusing agent; an energy source to apply energy to cause fusing, via the at least one agent, of the build material to form the 3D object of the build material, wherein the print control portion is to control at least the material distributor, the fluid dispenser, and the energy source to additively form the 3D structure.

11. The print control portion of claim 9, wherein the second 3D object comprises a plurality of second 3D objects spaced apart from each other within the interior portion of the first 3D object.

12. The 3D printing system of claim 8, wherein the print control unit includes an inventory engine to store data tracking inventory information regarding at least the embedded second 3D object within the first 3D object.

13. A method comprising: additively manufacturing a three-dimensional assembly including a first three-dimensional object and a second three-dimensional object, wherein the second three-dimensional object is constrained, via a first retention arrangement, relative to a cavity of the first three-dimensional object and the second three-dimensional object is selectively removable from the first three- dimensional object via forcible separation at the first retention arrangement.

14. The method of claim 13, wherein the additive manufacturing of the three- dimensional assembly comprises additively manufacturing the first three- dimensional object, the second three-dimensional object, and a third three- dimensional object which is retained, via a second retention arrangement, relative to an interior portion of the second three-dimensional object, the third three-dimensional object is forcibly separable from the second three- dimensional object at the second retention arrangement.

15. The method of claim 13, comprising arranging the second three- dimensional object to include a plurality of second three-dimensional objects spaced apart from each other.