Patent Publication Number: US-2019168305-A1

Title: Methods and apparatus for optimally positioning objects for automated machining

Description:
RELATED APPLICATION 
     This patent claims priority to Singapore Patent Application No. 10201710089 W, filed Dec. 5, 2017, and entitled “Methods and Apparatus for Optimally Positioning Objects for Automated Machining,” which is hereby incorporated by reference in its entirety. 
     FIELD OF THE DISCLOSURE 
     This disclosure relates generally to automated machining and, more particularly, to methods and apparatus for optimally positioning objects for automated machining. 
     BACKGROUND 
     Additive manufacturing (AM), sometimes referred to as 3D printing, generally refers to a variety of processes that can be used to create a three-dimensional structure by adding layer-upon-layer of material to build the structure. Although the resolution of a structure produced by an AM machine is sometimes sufficient for a given application, one or more subtractive manufacturing processes (e.g., drilling, cutting, etc.) are often performed on the structure after the AM process to achieve greater precision in the structure. 
     SUMMARY 
     An example build file generator disclosed herein includes an object file manager to identify a first toolpath volume associated with a first object to be formed via an additive manufacturing (AM) process. The first toolpath volume is based on a first toolpath of a first post-manufacturing process to be used on the first object. The object file manager is also to identify a second toolpath volume associated with a second object to be formed via the AM process. The second toolpath volume is based on a second toolpath of a second post-manufacturing process to be used on the second object. The example build file generator also includes a layout determiner to determine a layout of the first and second objects to be formed on a substrate by the AM process based on the first and second toolpath volumes. According to the layout, the first object is at least partially disposed within the second toolpath volume. 
     An example method of producing objects disclosed herein includes building, via an additive manufacturing (AM) machine, a first object and a second object on a substrate according to a build file. The build file defines a layout of the first object and the second object on the substrate. According to the layout, the second object is at least partially disposed within a first toolpath volume associated with the first object. The first toolpath volume is based on a first toolpath for a first post-manufacturing process to be performed on the first object. The example method also includes removing the second object from the substrate and, after removing the second object from the substrate, performing, via a first post-manufacturing machine, the first post-manufacturing process on the first object while the first object is fixed on the substrate. 
     A non-transitory machine readable storage medium disclosed herein includes instructions that, when executed, cause at least one machine to at least identify a first toolpath volume associated with a first object to be formed via an additive manufacturing (AM) process, where the first toolpath volume is based on a first toolpath of a first post-manufacturing process to be performed on the first object, and identify a second toolpath volume associated with a second object to be formed via the AM process, where the second toolpath volume based on a second toolpath of a second post-manufacturing process to be performed on the second object. The instructions, when executed, further cause the at least one machine to at least generate a build file for an AM machine based on the first toolpath volume and the second toolpath volume. The build file includes a layout of the first and second objects to be formed on a substrate by the AM machine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example build file generator, implemented in connection with an example automated machining system, to generate an example build file in accordance with the teachings of this disclosure. 
         FIG. 2  illustrates an example additive manufacturing machine that may be implemented in the example automated machining system of  FIG. 1  to build one or more objects according to an example layout defined by the example build file. 
         FIG. 3  is a side view of an example object built by the example additive manufacturing machine of  FIG. 2 . 
         FIG. 4  illustrates an example computer numerical control (CNC) machine that may be implemented in the example automated machining system of  FIG. 1  and used to perform one or more post-manufacturing process(es) on the example object of  FIG. 3 . 
         FIG. 5  illustrates an example toolpath volume that may be defined around the example object of  FIG. 3  and used by the example build file generator of  FIG. 1 . 
         FIG. 6  illustrates example objects and an example substrate on which the example object may be built. 
         FIG. 7  illustrates an example layout of the example objects of  FIG. 6  on the example substrate as defined by an example build file that may be generated by the example build file generator of  FIG. 1 . 
         FIGS. 8A-8J  illustrate an example sequence of post-manufacturing process(es) and removal of the example objects of  FIGS. 6 and 7  that may be determined by the example build file generator of  FIG. 1 . 
         FIGS. 9A and 9B  illustrate an example machine that may be implemented in the example automated machining system of  FIG. 1  and used to spray a protective foam on one or more objects. 
         FIG. 10  is a flowchart representative of example machine readable instructions that may be executed to implement the example build file generator of  FIG. 1 . 
         FIG. 11  is a flowchart representative of an example method that may be performed by one or more example machine(s) of the example automated machining system of  FIG. 1  to build one or more objects according to a sequence of post-manufacturing process(es) and removal as determined by the example build file generator. 
         FIG. 12  is a processor platform structured to execute the example instructions of  FIG. 10  to implement the example build file generator of  FIG. 1 . 
     
    
    
     The figures are not to scale. Instead, to clarify multiple layers and regions, the thickness of the layers may be enlarged in the drawings. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, area, or plate) is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, indicates that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Stating that any part is in contact with another part means that there is no intermediate part between the two parts. 
     DETAILED DESCRIPTION 
     Additive manufacturing (AM), sometimes referred to as three-dimensional (3D) printing, generally refers to a variety of manufacturing processes that can be used to create a three-dimensional object by adding layer-upon-layer of material to build the object. As used herein, the terms object, component, and part are defined to mean any 3D article that can be built via one or more machining processes, such as via an AM process. AM processes are now being used to create objects for almost any type of product, such as process control equipment (e.g., valves, regulators, sensors, etc.), vehicle parts, cellphone parts, etc. In some types of AM processes, such as powder bed fusion, the object is built on a substrate. As used herein, a substrate is defined to mean any piece of material (e.g., metal, plastic, etc.) upon which one or more objects may be built. With a powder bed fusion machine, for example, the object(s) is/are welded and/or otherwise coupled at its/their base to the substrate. After an object is built on the substrate, the object may be separated from the substrate. 
     In some examples, to achieve the necessary specifications or improve properties of the object such as, for example, surface quality, geometric accuracy, mechanical properties, etc., it may be desired or necessary to perform one or more post-manufacturing process(es) on the object. The terms “post-process,” “post-manufacturing process,” and/or variations thereof are used herein to mean any process that may be performed on an object after the general shape of the object has been formed (e.g., by an AM process). For example, one or more subtractive manufacturing processes (e.g., drilling, cutting, etc.) may be used to remove temporary support structures built during the AM process, to improve the surface resolution of the object, to create additional edges or openings, etc. Further, other post-manufacturing processes, such as, for example, de-powdering, cleaning, 3D scanning, painting, heat treating, shot peening, electrochemical treatment, etc., may be used to improve the mechanical and/or tactile properties of the surface of additively manufactured parts. 
     In some instances, it is beneficial to retain the object on the substrate while performing the one or more post-manufacturing process(es). For example, some objects may not have a suitable fixture point (e.g., because of their complex geometries) to fix the object to a machine for post-manufacturing processing. Thus, if the object is removed, an appropriate fixture point has to be added or an additional structure (which acts as a fixture point) has to be created on the object during the AM process. Also, fixing an object to a machine requires significant time and, thus, reduces cost efficiency. 
     To increase the efficiency of the AM process, it is often desired to build multiple objects on the substrate at the same time. The objects may be arranged in a relatively dense layout to fit as many objects on the substrate as possible, which increases (e.g., maximizes) the number of objects that can be produced in a single batch. Further, as mentioned above, one or more post-manufacturing process(es) are often desired or needed to finish the object(s). However, these post-manufacturing process(es) require room or space around the respective objects to accommodate the toolpaths of the respective post-manufacturing process(es). As such, the objects would need to be spaced apart from each other to accommodate the toolpaths of the post-manufacturing machines. However, increasing the spacing between the objects results in fewer objects being built on a common substrate and, thus, lowers the efficiency of the build processes. For example, while a high-density layout may maximize build efficiency, such a high-density layout often prevents a post-manufacturing process tool, such as a bit of a computer numeric control (CNC) machine, from accessing each object. In other words, the other objects on the build substrate may obstruct the toolpath of the post-manufacturing machine. While it may be possible to remove the objects from the substrate and post-process the objects individually, as explained above, individually fixing objects to post-manufacturing machine(s) is extremely time consuming, which reduces efficiency and productivity. Any increased efficiency and productivity gained through the use of a high-density layout may be lost to the inefficiencies introduced by individually post-processing each object of a batch. 
     Disclosed herein are example methods, apparatus, systems, and articles of manufacture for generating a build file or model that enables a high-density layout of objects while permitting the objects to be machined while the objects are still fixed to the substrate. The examples disclosed herein select a plurality of objects and determine an optimal layout of the objects to be built or formed on a common substrate based on toolpath volumes associated with the respective objects. As used herein, a “toolpath volume” means a volume around an object that a tool of a post-manufacturing machine occupies during a post-manufacturing process performed on the object and which is to be kept clear to avoid a collision with another object. Thus, a toolpath volume may be represented by, for example, a set of coordinates or distances relative to the object (e.g., relative to a center point of the object, relative to an edge or surface of the object, etc.) that define(s) one or more boundaries around the object. 
     An example build file generator disclosed herein analyzes a plurality of object files (representing objects to be built via an AM process) and machining files associated with the object files that define toolpath volumes around each of the objects. The example build file generator may select two or more objects (e.g., from a larger set of possible objects) and define a layout of the objects to be built on a common substrate using an AM machine based on the toolpath volumes associated with the objects. The example build file may be used by an AM machine to build the objects on the substrate according to the defined layout. 
     In some examples, the build file generator also determines a sequence of post-manufacturing process(es) and removal that is to be performed on the objects on the substrate. The sequence, which may be stored as a separate file (e.g., a machining file for the build) or included as part of the build file, defines an order in which the one or more post-manufacturing process(es) are to be performed on each of the objects and/or the sequence of removal of the objects. For example, a sequence may specify that (1) a first post-manufacturing process is to be performed on a first object and then the first object is to be removed, (2) a second post-manufacturing process (which may be the same or different as the first post-manufacturing process) is to be performed on a second object and then the second object is to be removed, and so forth. By using the example sequence, one or more of the objects may be positioned within (or partially within) a toolpath volume of another object because the example sequence ensures that the toolpath volume around each of the objects is clear before the post-manufacturing and/or removal of the next object(s) is/are initiated. For example, a layout may specify that a first object and a second object are to be built on a substrate where the first object is disposed within (or partially within) the toolpath volume of the second object. The sequence may specify that the one or more post-manufacturing process(es) that are to be performed on the first object are to be performed first, and then the first object is to be removed. Then, the one or more post-manufacturing process(es) that are to be performed on the second object can be performed, because the area around the second object (which was previously occupied by the first object) is now clear, and so forth. As a result, the objects can be arranged in a layout that increases (e.g., maximizes) the density of objects on the substrate, thereby decreasing the total build time of the objects and increasing efficiency of the machining process. 
     Thus, example methods, apparatus, systems, and articles of manufacture disclosed herein enable a high-density object layout on a substrate while permitting the objects to be machined while the objects are attached to the substrate. A high-density object layout reduces total production time required to produce a set of (e.g., two or more) objects, thereby increasing efficiency and productivity. Further, the example methods, apparatus, systems, and articles of manufacture solve the problem associated with performing post-manufacturing processes on a high-density object layout by using the toolpath volumes of each object and defining the layout and sequence of removal based on the toolpath volumes. Thus, the example methods, apparatus, systems, and articles of manufacture enable the objects to remain fixed to the substrate during the post-manufacturing processing. By obviating the need to remove each object from the substrate, individually fixing each object to the post-manufacturing machine(s), and individually machining each part, the examples disclosed herein further increase the efficiency and productivity of the manufacturing and post-manufacturing processes. 
     Turning now to the figures,  FIG. 1  illustrates an example automated machining system  100  that may be used to manufacture one or more objects. The automated machining system  100  may be part of a machining or manufacturing facility (e.g., a 3D printing facility), for example, that receives work orders and produces the objects according the specifications of the work orders. In the illustrated example, the automated machining system  100  includes an additive manufacturing (AM) machine  102  that builds one or more objects via an AM process and one or more post-manufacturing machine(s)  104  that perform one or more post-manufacturing process(es) on the object(s) after being built by the AM machine  102 . In the illustrated example, the AM machine  102  builds the one or more object(s) on a substrate  106  according to a build file  108  (sometimes referred to as a build model), which defines the shapes, boundaries, orientations, etc. of the object(s) to be built or formed (as disclosed in further detail herein). The example substrate  106  (with a plurality of example objects) is illustrated in  FIG. 1  as being transferred from the AM machine  102  to the post-manufacturing machine(s)  104 . After the object(s) are created on the substrate  106  by the AM machine  102 , one or more post-manufacturing process(es) may be performed on the object(s), including removal of the object(s) from the substrate  106 . 
     Referring briefly to  FIG. 2 ,  FIG. 2  illustrates an example powder bed fusion machine  200 , which is a type of AM machine that may be implemented as the AM machine  102  of  FIG. 1 . The powder bed fusion machine  200  may be used to build one or more object(s) on a substrate, such as the substrate  106 , according to a build file, such as the build file  108  ( FIG. 1 ). The substrate  106  may be, for example, a metal plate. In the illustrated example, the powder bed fusion machine  200  includes a build platform  202  that is moveable up and down via a platform motor  204 . To create one or more objects, the substrate  106  is placed on the build platform  202 . Then, a roller  206  spreads a thin layer (e.g., 40 microns) of powder material  208  from a reservoir  210  (e.g., a hopper) over a top of the substrate  106  and the build platform  202 . The powder material  208  may be any metal and/or polymer based material. Then, a laser  212  applies energy to the layer of powder material  208  (in the shape of a cross-section of the 3D object(s) according to the build file), which sinters, fuses, and/or otherwise hardens the powder material  208  to form a layer of the object(s). In this example, the first layer of the object(s) is/are welded to the substrate  106 . Next, the build platform  202  is moved downward a small amount, (e.g., 0.1 millimeter (mm)) via the platform motor  204 , and the roller  206  spreads another layer of the powder material  208  over the build platform  202  and over the first hardened layer(s). The laser  212  then applies energy to the powder material  208  to harden the material onto the previous layer(s). This process is repeated to build the object(s) layer-by-layer. An example object  214  is illustrated in  FIG. 2 , which is welded to the substrate  106 . 
     The loose, unfused powder material  208  surrounding the object(s) on the build platform  202  remain in position throughout the process and is removed at the end (e.g., via a de-powdering unit). Other types of powder bed fusion AM processes may be completed by a variety of techniques such as, for example, direct metal laser sintering, electron beam melting, selective heat sintering, selective laser melting, selective laser sintering, etc. Powder bed fusion methods use either a laser or electron beam to melt and fuse material powder together. While some of the examples disclosed herein are described in connection with a powder bed fusion AM machine, the examples disclosed herein can likewise be implemented with any other type of AM process or machine, such as VAT photopolymerisation, material jetting, binder jetting, material extrusion, sheet lamination, and/or directed energy deposition. 
     Building objects with an AM machine, such as the powder bed fusion machine  200 , requires significant time because the objects are built by creating thousands of thin layers of material (or even more). For example, an object having 10,000 layers may require several hours, or even days to produce. One of the major efficiency factors that contributes to the AM process time is the re-spreading process/time. Therefore, if multiple objects can be built next to each other at the same time, the total number of respreads that would otherwise be needed is greatly reduced (as compared to building multiple objects at separate times), because the cross-sections of multiple objects can be created using the same spread. Thus, it is often desirable to select a set of objects and position the selected objects in a high-density layout on the substrate  106 . Increasing the density of a layout is one way to maximize the number of objects that can be produced in a single batch, thereby reducing the number of batches needed to produce a set of objects. 
     However, after the object(s) are built via the AM process, one or more post-manufacturing process(es) are often needed or desired to finish the respective object(s) according to a desired specification. For example, an object may be built with one or more temporary support structures within openings or arches of the object. After building the object, the temporary support structures are to be removed. Further, one or more processes may be desired to smooth the surface(s) of the object (because of the potentially rough (non-smooth) surface texture created via the AM process). Thus, one or more post-manufacturing process(es) may need or be desired to be performed on the object(s). 
     For example,  FIG. 3  illustrates an enlarged side view of the example object  214  built using the powder bed fusion machine  200  of  FIG. 2 . As shown, the object  214  includes an opening  300  extending through the object  214 . During the AM process, one or more temporary support structures  302  are built inside of the opening  300  to support the arch (the top side of the opening). Therefore, it may be desirable to remove the support structures  302  using a subtractive manufacturing machine (e.g., drilling). Additionally or alternatively, in some examples, it may be desirable to smooth one or more surfaces or edges of the object  214 . 
       FIG. 4  illustrates an example CNC machine  400  that may be implemented as one of the post-manufacturing machine(s)  104  of  FIG. 1  and which may be used to perform one or more subtractive manufacturing processes on one or more object(s), such as the object  214  of  FIGS. 2 and 3 . The CNC machine  400  includes a robotic arm  402  with a bit  404  for removing material from the object  214 . The robotic arm  402  can be controlled to move to the bit  404  to various locations around or through the object  214  to remove material. Therefore, to perform one or more post-manufacturing process(es) on the object  214 , no other objects can be in the toolpath (e.g., the path of the robotic arm  402  and/or the bit  404 ) around the object  214 , otherwise a potential collision may occur. However, as mentioned above, it is often desired to keep objects as close together as possible and to keep the objects fixed to the substrate while performing the post-manufacturing process(es). 
     In particular, it is often beneficial to retain the objects on the substrate  106  while performing the one or more post-manufacturing process(es). For example, some objects (because of their geometries) may not have an appropriate fixture point to fix the object to a post-manufacturing machine. Thus, if the object is removed, an appropriate fixture point has to be added or an additional structure has to be created on the object during the AM process. Otherwise, a specialized fixture has to be built to interface with the object, which is expensive and time consuming. Also, fixing each object to a machine requires significant time and, thus, reduces cost efficiency. Further, in some instances, it may be desirable to perform the same post-manufacturing process on a plurality of the objects (e.g., cleaning, heat treating, painting, sand-blasting, etc.). Thus, rather than performing the process on each object separately, it may be more economical to perform the process on a batch of the objects at the same time. Therefore, in many instances, it is more economical and efficient to keep the objects fixed to the substrate  106  during the post-manufacturing process(es). However, as mentioned above, the post-manufacturing process(es) often include tools (e.g., drill bits, laser jets, etc.) that need to move around the object(s) to perform the respective process(es). As such, a space or volume around the object needs to be kept clear to accommodate the toolpath of the respective post-manufacturing process so that the tool does not contact another object on the substrate. 
     Referring back to  FIG. 1 , the example automated machining system  100  includes a build file generator  110  that may generate a build file defining a high-density layout of objects to increase the efficiency and productivity of the automated machining system  100 . In this example, the build file generator  110  is implemented on a computer  112 . The example build file generator  110  may be implemented as an application or software program executed by a processor of the computer  112 . For example, the example build file generator  110  may be implemented as or part of a computer-aided design (CAD) and/or computer-aided manufacturing (CAM) application or software program. While in the illustrated example the build file generator  110  is implemented on the computer  112 , in other examples, the build file generator  110  may be implemented on another type of computing device, such as a laptop, a tablet, a phone (e.g., a smart phone), a server, and/or any other electronic device. 
     In the illustrated example, the computer  112  receives a plurality of object files  114   a - 114   n  defining respective objects  116   a - 116   n  to be built via an AM process (e.g., via the powder bed fusion machine  200  of  FIG. 2 ) in the example automated machining system  100 . The object files  114   a - 114   n  define the dimensions of the respective objects  116 - 116   n  and/or any other parameters or characteristics of the objects  116 - 116   n  (e.g., the type of material to be used for building the object, the desired finish characteristics, tolerances, etc.). In some examples, the object file(s)  114   a - 114   n  may include or define the location of one or more support structures (e.g., the support structure  302  of  FIG. 3 ) to be built with the respective object(s)  116   a - 116   n.    
     In some examples, one or more of the object file(s)  114   a - 114   n  include an associated machining file  117   a - 117   n , which includes the instructions for one or more post-manufacturing process(es) to be performed on the respective object  116   a - 116   n . In some examples, the machining files  117   a - 117   n  include the toolpath volumes for the respective objects  116   a - 116   n . Each toolpath volume represents a boundary in 3D space that is to be kept clear for the tool(s) of the post-manufacturing machine(s)  104  to perform the post-manufacturing process(es) on the respective object(s)  116   a - 116   n . In some examples, one or more of the machining file(s)  117   a - 117   n  include multiple toolpaths for the respective object. For example, there may be multiple toolpath routes for a post-manufacturing machine to accomplish the same machining process and/or there may be different types of post-manufacturing machines that can accomplish the same machining process using different toolpath routes. The toolpath volume(s) for an object may have been determined manually, for example, by a machinist and/or via a software program. For example, an object may be built (according to its object file) via an AM process, and then a machinist may develop the machining file for the object based on the one or more post-manufacturing process(es) used to finalize the object. The machinist may define the toolpath volume(s) for the object based on the space or clearance needed during the one or more post-manufacturing process(es). The toolpath volume(s) may be included as part of the machining files  117   a - 117   n  and/or the respective object files  114   a - 114   n  for the objects  116   a - 116   n . While the example machining files  117   a - 117   n  are depicted as being separate files in  FIG. 1 , in other example, the machining files  117   a - 117   n  may be part of the respective object files  114   a - 114   n  for the objects  116   a - 116   n.    
     In some examples, the object files  114   a - 114   n  may be received as work orders. The work orders may include other information, such as a request date, an expected delivery date, special instructions for delivery, etc. In some examples, one or more of the object file(s)  114   a - 114   n  and/or the machining file(s)  117   a - 117   n  are part of a library of objects. In such an example, one or more work orders may be received to build one or more of the object(s)  116   a - 116   n  from the library. The object file(s)  114   a - 114   n  and/or the associated machining file(s)  117   a - 117   n  may be stored in a memory  120 , for example. As such, the object file(s)  114   a - 114   n  and the corresponding toolpath volume(s) for each of the object(s)  116   a - 116   n  may be stored in the memory  120 . Additionally or alternatively, the computer  112  may receive one or more of the object file(s)  114   a - 114   n  and/or the associated machining file(s)  117   a - 117   n  via any wired or wireless connection. For example, one or more of the object file(s)  114 - 114   n  and/or the associated machining file(s)  117   a - 117   n  may be transmitted over the Internet to the computer  112 , uploaded via a thumb-drive or other storage medium, etc. In some examples, one or more of the object files  114   a - 114   n  and/or the associated machining file(s)  117   a - 117   n  are generated on the computer  112  (e.g., via a CAD software program). 
     In the illustrated example, the build file generator  110  includes an object file manager  118  that receives and manages the object files  114 - 114   n  and/or the associated machining file(s)  117   a - 117   n . In some examples, the object file manager  118  extracts information from the object files  114 - 114   n  and/or the associated machining file(s)  117   a - 117   n  and organizes or sorts the object files  114 - 114   n  and/or the associated machining file(s)  117   a - 117   n  based on, for example, number of objects to be built, size of the respective object to be built, size of the associated toolpath volume, request date, expected delivery date, etc. In some examples, the object files  114 - 114   n  (and the associated machining file(s)  117   a - 117   n ) to be built are saved in the memory  120 . 
     In some examples, as disclosed above, the toolpath volumes for the objects  116   a - 116   n  may be predefined (e.g., included in the associated machining files  117   a - 117   n ). In other examples, such as with a new object or object file, the build file generator  110  may include a volume definer  122 . The volume definer  122  may define one or more toolpath volumes around an object based on the desired post-manufacturing process(s) to be performed on the respective object. In some examples, the toolpath volume(s) (e.g., as defined by distances from the surfaces of the object) are saved in the memory  120  with the associated object files. 
     As mentioned above, in many instances, one or more post-manufacturing process(es) are to be performed on the object(s)  116   a - 116   n  by the post-manufacturing machine(s)  104  after the object(s)  116   a - 116   n  are built on the substrate  106  by the AM machine  102 . The example post-manufacturing machine(s)  104  and/or process(es) may include subtractive type manufacturing processes such as, for example, CNC machining (e.g., performed by the CNC machine  400  of  FIG. 4 ), laser etching (e.g., to etch a serial number into an object), electrical discharge machining (EDM), electro-chemical erosion, laser cutting, water cutting, polishing, turning, drilling, boring, reaming, milling, shaping, planing, broaching, sawing, cutting, abrasive flow machining, etc. Additionally or alternatively, example post-manufacturing machine(s)  104  and/or process(es) may include other types of machine(s) and/or process(es), such as de-powdering units, washing units, painting, media blasting, priming, heat treating, 3D scanning, a coordinate measuring machine (CMM), shot peening, etc. 
     For example, referring briefly to  FIG. 5 ,  FIG. 5  shows an example toolpath volume (shown in dashed lines) around the object  214  (which may correspond to one of the objects  116   a - 116   n ). The toolpath volume represents the space around the object  214  that one or more tool(s) of the post-manufacturing machine(s)  104  may travel when performing operations (e.g., drilling, cleaning, measuring, painting, etc.) on the object  214 . 
     In some examples, the specific post-manufacturing process(es) to be performed on an object are defined by the associated machining file. For example, the one or more post-manufacturing process(es) may be pre-selected based on certain specifications of the object (e.g., based on a certain tolerance or surface smoothness to be achieved). In such an example, one or more post-manufacturing process(es) may be selected to smooth the surfaces of the object after the object is built by the AM machine  102  and defined in the associated machining file. Additionally or alternatively, a user (e.g., a customer) may request one or more post-manufacturing process(es) (e.g., sand blasting, cutting, painting, etc.) to be performed on the object after being built by the AM machine  102 . In other examples, one or more post-manufacturing process(es) may be selected in other manners and/or based on other considerations. The toolpath volume may depend on one or more factors, such as the size and shape of the respective object, the type of post-manufacturing process(es) to be performed, the type of post-manufacturing machine(s) (e.g., a model of CNC machine) used to perform the process(es), etc. Different ones of the post-manufacturing machine(s)  104  and/or process(es) may result in different toolpath volumes around an object to perform the respective post-manufacturing process(es). 
     To determine the layout of object(s) and/or sequence of post-manufacturing process and removal of the object(s), the example build file generator  110  includes a layout and sequence determiner  124  (sometimes referred to as a layout determiner). The layout and sequence determiner  124  analyzes the sizes of the objects  116   a - 116   n  (and/or the possible orientations of the objects  116   a - 116   n ), the sizes of the toolpath volumes associated with the objects  116   a - 116   n , and/or the size of the substrate  106  and determines a layout of a plurality of the objects  116   a - 116   n  on the substrate  106  that results in a dense arrangement (e.g., an arrangement that consumes the smallest area of the substrate  106 ). Additionally or alternatively, the layout and sequence determiner  124  may consider one or more other factors or parameters when selecting the objects  116   a - 116   n  to build on the same substrate, such as the other possible toolpath routes or volumes associated with an object, a request date of an object (e.g., a date a work order was place), a promise date of a work order, the anticipated time of completing the object, etc. In some examples, a user may be able to weigh these factors based on importance. 
     The example layout and sequence determiner  124  determines a layout that maximizes the density of objects to be built. In some examples, the layout and sequence determiner  124  selects a subset of objects (e.g., two or more objects) from the plurality of objects  116   a - 116   n . Further, the layout and sequence determiner  124  determines a sequence of post-manufacturing processes that are to be performed on the object(s)  116   a - 116   n  and removal of the object(s)  116   a - 116   n . An example of this process is disclosed in further detail in conjunction with  FIGS. 8A-8J . In some examples, one or more of the object(s)  116   a - 116   n  built on the same substrate  106  are a same type of object. In other examples, a plurality of different types of objects are to be built on the same substrate  106 . 
     In some examples, the example build file generator  110  includes an AM formatter  126  that formats, renders and/or otherwise generates the build file  108  based on the layout and sequence determined by the layout and sequence determiner  124  for building in the AM machine  102 . For example, the AM formatter  126  may format the build file  108  for the specific type(s) of machine(s) that are going to build and/or work on the objects. For example, the AM formatter  126  may convert the layout into a stereo lithography file (STL file) or other type of AM file for use by the AM machine  102 . In some examples, the AM formatter  126  includes a slicer that creates or defines each of the layers to be built by the AM machine  102  and, thus, provides the instructions for building the object(s)  116   a - 116   n  according to the layout. In other examples, the AM formatter  126  may perform one or more other process(es) (e.g., numerical control (NC) deposition control) to format the layout to be built by the AM machine  102 . In other examples, the build file  108  may include an unformatted version of the layout and shapes of the object(s) and the AM machine  102  may perform any formatting to create the instructions (e.g., instructions for the laser) for creating the objects  116   a - 116   n.    
     Once the build file  108  is generated, the AM machine  102  may build the object(s)  116   a - 116   n  on the substrate  106  according to layout defined by the build file  108 . In some examples, the build file  108  is transmitted to the AM machine  102  via a wired or wireless connection (e.g., an intranet system of a machining or manufacturing facility). In some examples, the build file  108  is transferred to the AM machine  102  via a storage medium (e.g., a thumb drive, a CD, etc.). In other examples, the computer  112  may be a computer or workstation associated with the AM machine  102  for operating the AM machine  102  and, thus, the build file  108  is not transferred outside of the computer  112 . 
     After the object(s)  116 - 116   n  are built or formed on the substrate  106 , the one or more post-manufacturing process(es) are performed on the object(s)  116 - 116   n  via the post-manufacturing machine(s)  104  and the object(s) are removed from the substrate  106 . The post-manufacturing process(es) and removal are performed according to the sequence defined by the layout and sequence determiner  124 . In some examples, one or more post-manufacturing process(es) may be performed on multiple ones of the object(s)  116   a - 116   n  on the substrate  106  at the same time. For example, after the object(s)  116   a - 116   n  are built on the substrate  106 , the substrate  106  (along with the associated objects  116   a - 116   n ) may be sent to a de-powdering unit to de-powder the substrate  106 , may be sent to a washer to be cleaned, may be sent to a heater for heat treatment, may be sent to a 3D scanner or CMM to identify/confirm the measurements and shapes of the object(s)  116 - 116   n , etc. Thus, in some examples, one or more post-manufacturing process(es) may be performed on multiple ones of the object(s)  116 - 116   n  before the object(s)  116 - 116   n  are removed in sequence (and/or additional post-manufacturing processes are performed on the object(s)  116 - 116   n ). 
     In some examples, the layout and sequence determiner  124  may determine the layout and sequence based on common post-manufacturing process(es) that are to be performed on multiple ones of the object(s)  116   a - 116   n . For example, the sequence may include performing a post-manufacturing process (e.g., using a certain cutter) on multiple ones of the objects  116   a - 116   n  that require the same post-manufacturing process at the same time or immediate sequence before further processing the objects  116   a - 116   n  and/or removing the objects  116   a - 116   n , rather than performing each machining sequence for each of the objects  116   a - 116   n  all the way through. In some examples, the object files  114   a - 114   n  and/or machining files  117   a - 117   n  for the object  116   a - 116   n  may define the individual or discrete toolpath volumes for each of the post-manufacturing process(es) to be performed on a respective object, rather than a total toolpath volume for all of the tools paths used on a certain object. In some such examples, the layout and sequence determiner  124  may consider the individual toolpath volumes for each of the post-manufacturing process to be performed each of the objects  116   a - 116   n  when determining the layout and sequence, to ensure no collision occurs when using the same post-manufacturing process to machine on multiple ones of the objects  116   a - 116   n  at the same time or in an order. As such, rather than implementing a sequence where the substrate  106  is sent back to the same post-manufacturing machine at various times, the sequence may include performing the post-manufacturing process on the corresponding objects at the same time or in an immediate order (depending on the space limitations), which increases efficiency and productivity. 
     In some examples, the build file generator  110  includes a machining file generator  128  that generates a machining file  130  for the build (e.g., the batch of objects on the substrate  106 ) that includes the determined sequence. The machining file  130  may be stored in the memory  120 , for example, as associated with the build file  108 . The machining file  130  may be transmitted (via a wired or wireless connection) to the post-manufacturing machine(s)  104 , which may perform the post-manufacturing process(es) on the object(s)  116   a - 116   n  in accordance with the sequence. In some examples, the machining file  130  includes the individual machining file(s)  117   a - 117   n  of the object(s)  116   a - 116   n  on the substrate  106 , such that the post-manufacturing machine(s)  104  can perform the specified post-manufacturing process(es) according to the respective machining file(s)  117   a - 117   n . In some examples, the machining file generator  128  generates and/or transmits one or more inspection files along with the machining file  130  that is/are associated with the build. An inspection file may include instructions for a 3D scan or CMM program, for example, that may occur before or after one or more the object(s)  116   a - 116   n  is/are removed from the substrate  106 . The inspection file(s) may be used to ensure the object(s)  116   a - 116   n  is/are built to the proper specification (e.g., within a threshold) (by the AM machine  102 , for example) before starting one or more other post-manufacturing process(es) (e.g., machining) and/or that the object(s)  116   a - 116   n  meet their final dimensional specifications (e.g., with a threshold) before being removed from the substrate  106 , for example. 
       FIG. 6  is a plan view showing example objects to be built on the substrate  106 . In particular,  FIG. 6  shows nine objects  116   a - 116   i . The toolpath volumes are shown around each of the objects  116   a - 116   i  in dashed lines for illustrative purposes. The toolpath volumes may be obtained from the machining files  117   a - 117   i  associated with the objects  116   a - 116   i  and/or defined by the volume definer  122  ( FIG. 1 ), for example. As disclosed herein, the toolpath volumes represent the space around the respective objects  116   a - 116   i  needed for the one or more post-manufacturing process(es) to be performed on the objects  116   a - 116   i . In the illustrated example, the first and second objects  116   a ,  116   b  are a same type of object and the third, fourth, seventh, and eighth objects  116   c ,  116   d ,  116   g ,  116   h  are a same type of object. As can be understood by looking at  FIG. 6 , the toolpath volumes around the objects  116   a - 116   i  create a relatively large area, while the substrate  106  has a relatively small area. If the objects  116   a - 116   i  were to be spaced on the substrate  106  such that none of the toolpath volumes overlapped, only a few of the parts could be built, or a much larger substrate and AM machine would be needed. The layout and sequence determiner  124  determines a layout and sequence of removal that enables the objects  116   a - 116   i  to be post-processed and removed without interfering with each other while still arranging the objects in a relatively dense spatial arrangement to fit the most objects on the same substrate  106 . 
       FIG. 7  illustrates an example layout  700  determined by the layout and sequence determiner  124 . Use of the build file generator  110  enables the objects  116   a - 116   i  to be densely arranged on the substrate  106  in a layout that would otherwise not be achievable. As illustrated, many of the objects  116   a - 116   i  are disposed within (or partially within) the toolpath volumes of the other objects  116   a - 116   i . For example, according to the layout  700 , the first object  116   a  is disposed within the toolpath volume associated the second object  116   b . However, because the objects  116   a - 116   i  are removed according to a sequence, the toolpath volume for each subsequent object is opened up. An example sequence for post-processing and removal of the objects  116   a - 116   i  may be, for example, (1) the first object  116   a , (2) the second object  116   b , (3) the third object  116   c , (4) the fourth object  116   d , (5) the fifth object  116   e , (6) the sixth object  116   f , (7) the seventh object  116   g , (8) the eighth object  116   h , and (9) the ninth object  116   i . In some examples, as disclosed herein, an object may have multiple toolpath volumes that are possible with the associated object, and the layout and sequence determiner  124  may select between different ones of the toolpath volumes to create the densest layout with the other objects. For example, as illustrated in  FIG. 7 , the toolpath volumes for the seventh object  116   g  and the eighth object  116   h  are reversed as compared to the toolpath volumes for the third object  116   c  and the fourth object  116   d . Therefore, in some examples, multiple toolpath volumes (or different orientations of the same toolpath volume) are analyzed by the layout and sequence determiner  124  to determine the optimal arrangement of objects. 
     For example,  FIGS. 8A-8J  show an example sequence of the objects  116   a - 116   i  being processed (via one or more post-manufacturing process(es)) and/or removed from the substrate  106  according to the sequence. The toolpath volumes are also shown in dashed lines in the example  FIGS. 8A-8J  for illustrative purposes. As mentioned above, assume, for example, the first object  116   a  is the first object in the sequence to be post-processed (if a post-manufacturing process is desired) and removed from the substrate  106 . As shown in  FIG. 8A , there are no other objects disposed in the toolpath volume of the first object  116   a . Therefore, the post-manufacturing process(es) for the first object  116   a  can be performed on the first object  116   a  without the risk of tool collision. After the post-manufacturing process(es) are performed on the first object  116   a , the first object  116   a  is removed from the substrate  106 , as shown in  FIG. 8B . The first object  116   a  may be removed via a tool (e.g., a slotting tool, a mill, etc.) on the same post-manufacturing machine the performed the post-manufacturing process(es) (e.g., the CNC machine  400  of  FIG. 4 ) or another post-manufacturing machine. 
     Once the first object  116   a  is removed from the substrate  106 , the toolpath volume associated with the second object  116   b  is cleared. Then, the post-manufacturing process(es) to be performed on the second object  116   b  (e.g., which may be the same as the post-manufacturing process(es) performed on the first object  116   a ) can be performed on the second object  116   b . Then, similar to the first object  116   a , the second object  116   b  is removed from the substrate  106  (e.g., via a slotting tool, a mill, etc.), and the example sequence continues. As shown in  FIGS. 8A-8J , each time one of the objects  116   a - 116   i  is processed and removed from the substrate  106 , the toolpath volume for the next object in the sequence is cleared. While in this example nine objects are built on the substrate  106 , in other examples, more or fewer objects may be built on the substrate  106 . In some examples, only two objects are built on the same substrate. 
     In some examples, when one or more of the objects  116 - 116   i  are removed from the substrate  106 , the substrate  106  may be turned over or tilted to allow the respective object(s)  116   a - 116   i  to fall into a collection device, such as a catch shoot or a modified chip conveyor. In some examples, to prevent damage to the object(s)  116   a - 116   i  when removing and/or collecting the object(s)  116   a - 116   i , the objects  116   a - 116   i  may be protected. For example, in some instances, one or more protective covers (e.g., a corrugated polymer sock) may be placed (e.g., via an operator or an automated machine) on one or more of the objects  116   a - 116   i  before removing the respective object(s)  116 - 116   i  from the substrate  106 . Then, when the object(s)  116   a - 116   i  is/are removed from the substrate  106 , the object(s)  116   a - 116   i  is/are protected from potential damage when falling from the substrate  106 . 
     In another example, a protective foam may be sprayed onto the objects  116   a - 116   i . For example,  FIGS. 9A and 9B  illustrate an example machine  900  that may be used to spray a protective foam  902  onto one or more the object(s)  116 - 116   i  on the substrate  106 . The objects  116   a - 116   i  depicted in  FIGS. 9A and 9B  are not exactly the same or in the same positions as shown in  FIGS. 8A-8J , but are depicted merely for illustrative purposes. The machine  900  may correspond to one of the post-manufacturing machine(s)  104  ( FIG. 1 ), for example. In the illustrated example, the machine  900  includes a moveable nozzle  904  (as shown moving between  FIGS. 9A and 9B ) that sprays the protective foam  902 , which may harden or semi-harden to provide a cushioning layer on the surfaces of the objects  116   a - 116   i . The protective foam  902  may be, for example, an expanding urethane foam, a two part foam, and/or another type of foam. In some examples, a foam is selected that does not leave a residue on the object(s)  116   a - 116   i  after being removed (e.g., dissolved). The one or more post-manufacturing process(es) may be performed on the object(s)  116   a - 116   i  even with the protective foam  902 . As such, the protective foam  902  stays attached to the areas on the object(s)  116 - 116   i  that are not machined. The protective foam  902  protects the object(s)  116   a - 116   i  when they are removed from the substrate  106  and collected (e.g., dropped into a collection device). Further, the protective foam  902  may also reduce chatter in relatively larger (taller) parts and/or dampen machining chatter or vibration during the post-manufacturing process(es). Then, once the object(s)  116   a - 116   i  is/are removed, the protective foam  902  may be removed. For example, the protective foam  902  may be a soluble material (e.g., water soluble) that dissolves in a liquid solution (e.g., a non-toxic solvent). In other examples, the protective foam  902  may be removed via media blasting. 
     In some examples, instead of using the layout and sequence determiner  124  to determine the layout and sequence, the layout and/or sequence may be determined manually by a user. For example, the build file generator  110  may display, on a display screen of the computer  112 , an image of the substrate  106  and a plurality of the objects  116   a - 116   n  on to enable the user to position the object(s)  116   a - 116   n  in a desired layout (e.g., by clicking and dragging) on the substrate  106 . The object(s)  116   a - 116   n  may be displayed as 2D or 3D representations with the toolpath volumes around the respective object(s)  116   a - 116   n  so that the user can see how the object(s)  116   a - 116   n  are positioned relative to each other and to the toolpath volumes of the other object(s)  116   a - 116   n . The user may select one or more of the object(s)  116   a - 116   n  and position one or more of the object(s)  116 - 116   n  on the substrate  106  in a layout where one or more of the object(s)  116   a - 116   n  are disposed in a toolpath volume of one or more the object(s)  116   a - 116   n , as disclosed in accordance with the teachings of this disclosure. The user may also select the sequence of removal based on the layout. Then, when the desired layout is achieved, the build file generator  110  may remove the toolpath volumes, the build file formatter  126  may create the build file  108  for the AM machine  102  based on the final layout, and the machining file generator  128  may crate the machining file  130  based on the determined sequence. 
     While in the illustrated example of  FIG. 1  the build file generator  110  is illustrated as being part of the automated machining system  100  (e.g., part of a machining or manufacturing facility), in other examples, the build file generator  110  may be implemented by a computing device that is remote to the automated machining system  100 . For example, the build file generator  110  may be implemented by a cloud-based computing device (e.g., a server, a virtual machine, etc.) that is remote to a machining facility containing the AM machine  102  and the post-manufacturing machine(s)  104 . In such an example, the build file generator  110  may transmit the generated build file and/or determined sequence to the facility to be manufactured via the AM machine  102  and/or the post-manufacturing machine(s)  104 . In some examples, the computer  112  may be the same computing device that controls the operations of the AM machine  102  and/or the post-manufacturing machine(s)  104 . In other examples, one or more separate computing devices may be used to control the operations of the AM machine  102  and/or the post-manufacturing machine(s)  104 . 
     Also, while in the illustrated example the post-manufacturing machine(s)  104  are shown as separate from the AM machine  102 , it is understood that one or more of the post-manufacturing processes may be performed directly by the AM machine  102 . For example, the AM machine  102  may include one or more tools for de-powdering the substrate  106 , cleaning the objects  116   a - 116   n , cutting material, drilling material, etc. Thus, in some examples, after the object(s)  116 - 116   n  are built using the AM machine  102 , the object(s)  116 - 116   n  (along with the substrate  106 ) remain in the AM machine  102  for one or more post-manufacturing process(es). 
     Also, while in some of the examples disclosed herein the toolpath volumes are defined as volumes or 3D spaces around the respective object, in other examples, a toolpath area or zone having only two dimensions may be implemented. For example, a toolpath area or zone defined by X, Y coordinates may be used to define an area or zone relative to the respective object, without consideration of the Z direction. 
     In some examples, the sequence or one or more portions of the sequence is/are sent to the post-manufacturing machine(s)  104  (e.g., as part of the machining file  130 ) to perform the post-manufacturing process(es) and removal according to the sequence. In other examples, the sequence of post-manufacturing process(es) and removal for the objects of a substrate are included in the build file  108 . In such an example, the build file  108  (along with the sequence) may be sent to the post-manufacturing machine(s)  104  (and/or the machine for removing the objects). 
     As disclosed herein, in some examples, the build file generator  110  selects a subset of the objects  116   a - 116   n  to be built on the substrate  106  (e.g., a first batch). The example build file generator  110  may continue to generate build files with the remaining ones of the object(s)  116   a - 116   n  until all of the work orders are satisfied. Further, in some examples, multiple AM machines may be implemented in the automated machining system  100 . Therefore, in some examples, multiple AM processes may be used to build objects simultaneously. 
     While an example manner of implementing the example build file generator  110  is illustrated in  FIG. 1 , one or more of the elements, processes and/or devices illustrated in  FIG. 1  may be combined, divided, re-arranged, omitted, eliminated and/or implemented in any other way. Further, the example object file manager  118 , the example volume definer  122 , the example layout and sequence determiner  124 , the example AM formatter  126 , the example machining file generator and/or, more generally, the example build file generator  110  of  FIG. 1  may be implemented by hardware, software, firmware and/or any combination of hardware, software and/or firmware. Thus, for example, any of the example object file manager  118 , the example volume definer  122 , the example layout and sequence determiner  124 , the example AM formatter  126 , the example machining file generator  128  and/or, more generally, the example build file generator  110  could be implemented by one or more analog or digital circuit(s), logic circuits, programmable processor(s), application specific integrated circuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)) and/or field programmable logic device(s) (FPLD(s)). When reading any of the apparatus or system claims of this patent to cover a purely software and/or firmware implementation, at least one of the example object file manager  118 , the example volume definer  122 , the example layout and sequence determiner  124 , the example AM formatter  126 , and/or the example machining file generator  128  is/are hereby expressly defined to include a non-transitory computer readable storage device or storage disk such as a memory, a digital versatile disk (DVD), a compact disk (CD), a Blu-ray disk, etc. including the software and/or firmware. Further still, the example build file generator  110  of  FIG. 1  may include one or more elements, processes and/or devices in addition to, or instead of, those illustrated in  FIG. 1 , and/or may include more than one of any or all of the illustrated elements, processes and devices. 
     A flowchart representative of example machine readable instructions for implementing the build file generator  110  of  FIG. 1  is shown in  FIG. 10 . In this example, the machine readable instructions comprise a program for execution by a processor such as the processor  1212  shown in the example processor platform  1200  discussed below in connection with  FIG. 12 . The program may be embodied in software stored on a non-transitory computer readable storage medium such as a CD-ROM, a floppy disk, a hard drive, a digital versatile disk (DVD), a Blu-ray disk, or a memory associated with the processor  1212 , but the entire program and/or parts thereof could alternatively be executed by a device other than the processor  1212  and/or embodied in firmware or dedicated hardware. Further, although the example program is described with reference to the flowchart illustrated in  FIG. 10 , many other methods of implementing the example build file generator  110  may alternatively be used. For example, the order of execution of the blocks may be changed, and/or some of the blocks described may be changed, eliminated, or combined. Additionally or alternatively, any or all of the blocks may be implemented by one or more hardware circuits (e.g., discrete and/or integrated analog and/or digital circuitry, a Field Programmable Gate Array (FPGA), an Application Specific Integrated circuit (ASIC), a comparator, an operational-amplifier (op-amp), a logic circuit, etc.) structured to perform the corresponding operation without executing software or firmware. 
     As mentioned above, the example processes of  FIG. 10  may be implemented using coded instructions (e.g., computer and/or machine readable instructions) stored on a non-transitory computer and/or machine readable medium such as a hard disk drive, a flash memory, a read-only memory, a compact disk, a digital versatile disk, a cache, a random-access memory and/or any other storage device or storage disk in which information is stored for any duration (e.g., for extended time periods, permanently, for brief instances, for temporarily buffering, and/or for caching of the information). As used herein, the term non-transitory computer readable medium is expressly defined to include any type of computer readable storage device and/or storage disk and to exclude propagating signals and to exclude transmission media. “Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim lists anything following any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, etc.), it is to be understood that additional elements, terms, etc. may be present without falling outside the scope of the corresponding claim. As used herein, when the phrase “at least” is used as the transition term in a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. 
       FIG. 10  is a flowchart  1000  representative of example machine readable instructions that may be executed by a processor (e.g., a processor of the computer  112 ) to implement the build file generator  110  of  FIG. 1 . The example process of  FIG. 10  is described in connection with the example automated machining system  100  of  FIG. 1  having the AM machine  102  and the post-manufacturing machine(s)  104 . However, in other examples, the example process of  FIG. 10  may be implemented in connection with other types of systems or manufacturing facilities having more or fewer AM machines and/or post-manufacturing machines. 
     At block  1002 , the object file manager  118  receives a plurality of object files (e.g., work orders), such as the object files  114   a - 114   n , corresponding to objects to be manufactured via an AM process. At block  1004 , the object file manager  118  identifies or determines the one or more toolpath volumes associated with each of the objects. The toolpath volumes are associated with one or more toolpath(s) for one or more post-manufacturing process(es) that are to be performed on the respective objects. The toolpath volumes represent boundaries or coordinates defining a space that is to be cleared for the tool(s) of the post-manufacturing machine(s)  104  to perform the post-manufacturing process(es) on the respective objects. In some examples, the object file manager  118  identifies the toolpath volumes from the machining file(s)  117   a - 117   n  associated with the one or more object file(s)  114   a - 114   n . The object file(s)  114   a - 114   n  and the associated toolpath volumes may be stored in a library, for example. In some examples, one or more of the objects may have multiple toolpath volumes representing multiple possible toolpaths. Additionally or alternatively, the example volume definer  122  may define one or more toolpath volumes for one or more of the objects  116   a - 116   n . For example, the volume definer  122  may define a first toolpath volume associated with a first object, a second toolpath volume associated with a second object, and so forth. In such an example, identifying the toolpath volume(s) at block  1004  includes defining the volume(s) associated with one or more of the objects. In some examples, no post-manufacturing processes are to be performed on an object. In such an example, no toolpath volume is identified and/or defined. 
     At block  1006 , the layout and sequence determiner  124  performs an analysis based on the toolpath volumes (and/or one or more other parameters) and selects two or more (e.g., a set) of the objects  116   a - 116   n  to build on a same substrate and determines a layout and a sequence of post-manufacturing and removal for the objects. For example, the layout and sequence determiner  124  may perform a mathematical computation that analyzes the sizes of the objects  116   a - 116   n  (and/or the possible orientations of the objects  116   a - 116   n ), the sizes of the one or more toolpath volumes associated with each of the objects  116   a - 116   n , and/or the size of the substrate  106 . Additionally or alternatively, one or more other factors may be considered when selecting the objects to build on the same substrate, such as a request date of an object (e.g., a date a work order was placed), a promise date of a work order, the anticipated time of completing the object, etc. In some examples, the example layout and sequence determiner  124  determines a layout that maximizes the population density of the objects to be built (i.e., maximizes the number of objects on a given substrate). 
     In some examples, in the determined layout, one or more of the selected objects  116   a - 116   n  are disposed within (or partially within) the toolpath volume(s) of one or more other ones of the objects  116   a - 116   n . For example, as in the example layout  700  of  FIG. 7 , the first object  116   a  is disposed within the toolpath volume associated with the second object  116   b . However, as disclosed above in connection with  FIGS. 8A-8J , the sequence of post-manufacturing and removal of the objects  116   a - 116   i  enables the respective toolpath volumes to be cleared before the post-manufacturing process for a respective object is to be performed. 
     At block  1008 , the AM formatter  126  generates the build file  108  for the selected objects based on the determined layout. In some examples, the AM formatter  126  formats the build file  108  for a specific type of AM machine (e.g., generates the instructions for creating each layer of the object(s)). Once the build file  108  is generated, the build file  108  may be used by the AM machine  102  to create the object(s) on the substrate  106  according to the layout. At block  1010 , the machining file generator  128  generates the machining file  130  containing the sequence of post-manufacturing and removal of the objects. In some such examples, the machining file  130  is used by the post-manufacturing machine(s)  104  to perform the post-manufacturing process(es) and removal of the objects. In other examples, the determined sequence may be included as part of the build file  108 , which may instead be used by the post-manufacturing machine(s)  104 . In some examples, the machining file generator  128  generates one or more inspection files that may be used by one or more of the post-manufacturing machine(s)  104 , such as a 3D scanner or CMM, to ensure the object(s)  116   a - 116   n  are built to their proper specification before machining and/or removal. 
       FIG. 11  is a flowchart  1100  representative of an example method that may be performed by an AM machine and one or more post-manufacturing machine(s) to build one or more objects according to a sequence as determined by the build file generator  110 . The example process of  FIG. 11  is described in connection with the example automated machining system  100  of  FIG. 1  having the AM machine  102  and the post-manufacturing machine(s)  104 . However, in other examples, the example process of  FIG. 11  may be implemented in connection with other types of systems or manufacturing facilities having more or fewer AM machines and/or post-manufacturing machines. 
     At block  1102 , the AM machine  102  builds the objects  116   a - 116   n  on the substrate  106  according to the build file  108 , which defines the layout of the selected ones of the objects  116   a - 116   n . At block  1104 , one of the post-manufacturing machine(s)  104  (e.g., the CNC machine  400  of  FIG. 4 ) performs a first post-manufacturing process on the first one of the objects  116   a - 116   n  in the sequence. The sequence may be part of the machining file  130  and/or the build file  108  and provided to the post-manufacturing machines(s)  104 . The post-manufacturing process may include machining (e.g., via the CNC machine  400  of  FIG. 4 ) the object, for example. In some examples, only one post-manufacturing process is performed on the first object in the sequence. In other examples, multiple post-manufacturing processes are performed on the first object in the sequence via the same post-manufacturing machine or different post-manufacturing machine(s). 
     After the post-manufacturing process(es) is/are performed on the first object in the sequence, the first object, at block  1106 , is removed from the substrate  106  in accordance with the sequence. The first object may be removed from the substrate  106  using a slotting tool, for example. The first object may be removed from the substrate  106  using the same post-manufacturing machine. For example the CNC machine  400  that performed the first post-manufacturing process on the first object may also remove the first object from the substrate  106  using a slotting tool or milling tool. Thus, in some examples, the substrate  106  stays with the same machine that previously performed the post-manufacturing process at block  1104 . In other examples, the removal operation is performed by a different post-manufacturing machine. Thus, in some examples, the substrate  106  may be transferred (e.g., via an automated device) to another machine for removing the first object. 
     At block  1108 , one of the post-manufacturing machine(s)  104  (e.g., the CNC machine  400  of  FIG. 4 ) performs a second post-manufacturing process on a second one of the objects  116   a - 116   n , which is the next object in the sequence. Similar to the first object, one or more post-manufacturing processes may be performed on the second object by the same or different machines. At block  1110 , the second object is removed from the substrate  106 . Similar to the first object, the second object may be removed using a slotting tool. In other examples, another type of machine may be used to remove the second object. 
     At block  1112 , the example method includes determining if there are more objects on the substrate to be processed and/or removed. If there are more objects, the example method returns to blocks  1108  and  1110 , and one or more post-manufacturing processes are performed on the next object in accordance with the sequence and/or the object is removed in accordance with the sequence. The example process of blocks  1108 - 1112  may continue until all of the objects are processed and/or removed from the substrate  106 . While in the illustrated example the objects are removed after the associated post-manufacturing process(es) is/are performed on the object, in other examples, the sequence may include performing one or more post-manufacturing process(es) on multiple ones of the objects before removing an object. 
     In some examples, an initial post-manufacturing process, which may occur before removing the first object at block  1106 , includes spraying one or more of object(s)  116   a - 116   n  with a protective foam. The protective foam may be sprayed manually or with a machine, such as the machine  900  of  FIG. 9 . The protective foam may provide a cushioning layer to the object(s)  116   a - 116   n  to prevent damage the object(s)  116   a - 116   n  as they are removed from the substrate  106  and collected. 
     While the example processes of  FIGS. 10 and 11  are described in connection with an AM type process that creates the objects on a substrate, the example processes may be similarly performed with other types of machining processes that can produce objects on a substrate in close proximity. For example, the objects may instead be built on a substrate using a high volume CNC machine or a casting process. The example layout and sequence determination and post-manufacturing process/removal process(es) disclosed herein can likewise be used to enable the parts to be produced in a more compact manner on the substrate and remain on the substrate during the post-manufacturing processes, similar to examples disclosed herein. Thus, the examples disclosed herein can be applied to other types of manufacturing processes other than AM. 
       FIG. 12  is a block diagram of an example processor platform  1200  structured to execute the instructions of  FIG. 10  to implement the build file generator  110  of  FIG. 1 . The processor platform  1200  can be, for example, a server, a personal computer (e.g., the computer  112  of  FIG. 1 ), a mobile device (e.g., a cell phone, a smart phone, a tablet such as an iPad™), a personal digital assistant (PDA), or any other type of computing device. 
     The processor platform  1200  of the illustrated example includes a processor  1212 . The processor  1212  of the illustrated example is hardware. For example, the processor  1212  can be implemented by one or more integrated circuits, logic circuits, microprocessors or controllers from any desired family or manufacturer. The hardware processor may be a semiconductor based (e.g., silicon based) device. In this example, the processor  1212  may implement the example object file manager  118 , the example volume definer  122 , the example layout and sequence determiner  124 , the example AM formatter  126 , the example machining file generator  128  and/or, more generally, the example build file generator  110  of  FIG. 1 . 
     The processor  1212  of the illustrated example includes a local memory  1213  (e.g., a cache). The processor  1212  of the illustrated example is in communication with a main memory including a volatile memory  1214  and a non-volatile memory  1216  via a bus  1218 . The volatile memory  1214  may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS Dynamic Random Access Memory (RDRAM) and/or any other type of random access memory device. The non-volatile memory  1216  may be implemented by flash memory and/or any other desired type of memory device. Access to the main memory  1214 ,  1216  is controlled by a memory controller. 
     The processor platform  1200  of the illustrated example also includes an interface circuit  1220 . The interface circuit  1220  may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), and/or a PCI express interface. 
     In the illustrated example, one or more input devices  1222  are connected to the interface circuit  1220 . The input device(s)  1222  permit(s) a user to enter data and/or commands into the processor  1212 . The input device(s) can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a track-pad, a trackball, isopoint and/or a voice recognition system. 
     One or more output devices  1224  are also connected to the interface circuit  1220  of the illustrated example. The output device(s)  1224  can be implemented, for example, by display devices (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display, a cathode ray tube display (CRT), a touchscreen, a tactile output device, a printer and/or speakers). The interface circuit  1220  of the illustrated example, thus, typically includes a graphics driver card, a graphics driver chip and/or a graphics driver processor. 
     The interface circuit  1220  of the illustrated example also includes a communication device such as a transmitter, a receiver, a transceiver, a modem and/or network interface card to facilitate exchange of data with external machines (e.g., computing devices of any kind) via a network  1226  (e.g., an Ethernet connection, a digital subscriber line (DSL), a telephone line, coaxial cable, a cellular telephone system, etc.). 
     The processor platform  1200  of the illustrated example also includes one or more mass storage devices  1228  for storing software and/or data. Examples of such mass storage devices  1228  include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, RAID systems, and digital versatile disk (DVD) drives. In this example, the mass storage device  1228  may implement the memory  120 . 
     The coded instructions  1232  of  FIG. 10  may be stored in the mass storage device  1228 , in the volatile memory  1214 , in the non-volatile memory  1216 , and/or on a removable tangible computer readable storage medium such as a CD or DVD. 
     From the foregoing, it will be appreciated that example methods, apparatus, systems, and articles of manufacture have been disclosed for generating a build file that defines a high-density layout of objects. As a result, more objects can be built or formed with an AM machine in a shorter period of time. Further, example methods, apparatus, systems, and articles of manufacture disclosed herein enable objects to remain fixed to a substrate during the one or more post-manufacturing process(es), which may be advantageous, for example, with objects having complex geometries that are not easily fixable to the post-manufacturing machines. 
     Although certain example methods, apparatus, systems, and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, systems, and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.