WO2016033045A1

WO2016033045A1 - Systems and methods for interlocking part avoidance in three dimensional nesting

Info

Publication number: WO2016033045A1
Application number: PCT/US2015/046694
Authority: WO
Inventors: Gert Claes; Andrey MAKAREVYCH
Original assignee: Materialise N.V.; Materialise Usa, Llc
Priority date: 2014-08-25
Filing date: 2015-08-25
Publication date: 2016-03-03
Also published as: BE1022947B1; BE1022947A1

Abstract

Methods and apparatuses for improved 3D printing are disclosed. A system for avoiding interlocking parts in 3D nesting of a set of objects can include a nesting module which generates modified versions of any objects having a risk characteristic such as a tunnel or a cavity. The system can determine a nesting arrangement based on a modified set of objects which includes the modified versions. Once the nesting arrangement is determined, the modified versions can be replaced with their original counterparts and the objects can be printed without any interlocking or trapped objects.

Description

SYSTEMS AND METHODS FOR INTERLOCKING PART AVOIDANCE

IN THREE DIMENSIONAL NESTING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This Application claims the benefit of U.S. Provisional Application No. 62/041,545, filed August 25, 2014, the contents of which are hereby incorporated in their entirety.

BACKGROUND OF THE INVENTION

[0002] Methods of additive manufacturing may involve building items on a layer by layer basis, for example by laser sintering (LS) or selective laser melting (SLM). In these applications it is desirable to specify the three-dimensional placement and orientation of the parts making up those items virtually, before building them, so as efficiently use the raw material and maximize the yield per build volume. This process is known as "3D nesting."

[0003] Methods of automatically nesting parts are known which involve analyzing the size and shape of the parts and placing them within the build volume so as to pack as many parts as possible into the build volume. Certain part shapes, however, can be problematic for these programs. For example, smaller parts can be inadvertently nested inside larger, hollow parts with small openings, making it impossible to remove the smaller parts from the larger parts after printing (i.e., after the build is complete). Also, parts with loops or other openings can become interlocked with one another, making it impossible to separate those parts once the build is complete. Existing 3D nesting programs can detect trapped or interlocked parts before initiating a build, but these problems must be solved manually by the user.

[0004] Accordingly, there is a need for improved apparatuses and methods for nesting 3D parts to avoid these problems.

SUMMARY

[0005] This application describes methods and apparatuses for improved 3D printing by solving and/or avoiding interlocking error conditions in a 3D nesting arrangement. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 depicts an example of 3D nesting of a set of objects.

[0007] FIG. 2A depicts an example of two models displayed next to a build volume.

[0008] FIG. 2B depicts an example of a 3D nesting arrangement for the 3D objects comprising the models of FIG. 2A.

[0009] FIG. 3 depicts an example of nested objects illustrating an interlocking error condition.

[0010] FIG. 4 depicts another example of nested objects illustrating another interlocking error condition.

[0011] FIG. 5 depicts an example of a modified version of an object in accordance with an embodiment.

[0012] FIG. 6 depicts an example of a process for solving interlocking error conditions in a 3D nesting arrangement.

[0013] FIG. 7 depicts an example of a process for avoiding interlocking error conditions in a 3D nesting arrangement.

[0014] FIG. 8 depicts an exemplary system for designing and manufacturing an item by additive manufacturing.

[0015] FIG. 9 depicts a functional block diagram of one example of a computer of FIG. 8.

[0016] FIG. 10 depicts a process for manufacturing a 3D object.

[0017] FIG. 11 a high level system diagram of a computing system that may be used in accordance with one or more embodiments.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

[0018] The present application discloses apparatuses and methods for improved 3D printing by solving and/or avoiding interlocking error conditions in a 3D nesting arrangement. In embodiments, a set of objects to be printed can be analyzed to identify any objects which are potentially problematic for a nesting operation - e.g., objects with tunnels or cavities which might trap or interlock with other objects after the nesting operation is performed. Once those potentially problematic objects are identified, interlock-proof counterparts of those objects can be generated. The interlock proof counterparts can have the same dimensions as the original versions, except that any potentially problematic features (e.g., tunnels or cavities) can be closed or filled to the degree that the potential for trapping or interlocking with other objects is reduced or eliminated. A nesting operation can then be performed on a modified set of objects, including original versions of any objects without potentially problematic features and interlock-proof versions of any objects with potentially problematic features. Once the modified set is nested satisfactorily (e.g., to a desired nesting density and/or build height), any interlock-proof versions can be replaced with their original counterparts, and the print or build operation can then be commenced.

[0019] Various additive manufacturing technologies are known in the art, such as: Stereolithography (SL), Laser Sintering (LS) and Selective Laser Melting (SLM). In cases where a laser emitter is used in SL, LS, or SLM, the process may be generally referred to as Laser Additive Manufacturing (LAM).

[0020] Stereolithography (SL) is an optical additive manufacturing technique used for "printing" three-dimensional (3D) objects one layer at a time. An SL apparatus may employ, for example, an Ultraviolet (UV) Laser to cure a photo-reactive substance with emitted radiation. In some embodiments, the SL apparatus directs the UV laser across a surface of a photo-reactive substance, such as, for example, an ultraviolet-curable photopolymer ("resin"), in order to build an object one layer at a time. For each layer, the laser beam traces a cross-section of the object on the surface of the liquid resin, which cures and solidifies the cross-section and joins it to the layer below. After a layer has been completed, the SL apparatus lowers a manufacturing platform by a distance equal to the thickness of a single layer and then deposits a new surface of uncured resin (or like photo-reactive material) on the previous layer. On this surface, a new pattern is traced thereby forming a new layer. By repeating this process one layer at a time, a complete 3D part may be formed.

[0021] Laser sintering (LS) is another optical additive manufacturing technique used for 3D printing objects. LS apparatuses often use a high-powered laser (e.g. a carbon dioxide laser) to "sinter" (i.e. fuse) small particles of plastic, metal, ceramic, or glass powders into a 3D object. Similar to SL, the LS apparatus may use a laser to scan cross-sections on the surface of a powder bed in accordance with a CAD design. Also similar to SL, the LS apparatus may lower a manufacturing platform by one layer thickness after a layer has been completed and add a new layer of material in order that a new layer can be formed. In some embodiments, an LS apparatus may preheat the powder in order to make it easier for the laser to raise the temperature during the sintering process. [0022] Selective Laser Melting (SLM) is yet another optical additive manufacturing technique used for 3D printing objects. Like LS, an SLM apparatus typically uses a high-powered laser to selectively melt thin layers of metal powder to form solid metal objects. While similar, SLM differs from LS because it typically uses materials with much higher melting points. When constructing objects using SLM, thin layers of metal powder may be distributed using various coating mechanisms. Like SL and LS, a manufacturing surface moves up and down to allow layers to be formed individually.

[0023] Using these various additive manufacturing technologies, in some cases one 3D object is printed at a time, and in some cases, multiple 3D objects are printed at a time. For example, LS may be used by an additive manufacturing apparatus to print multiple 3D objects at a given time, whether multiple versions of the same object or multiple different objects which might be assembled together to form a larger object. The multiple 3D objects may be nested in 3D in the total volume that the additive manufacturing apparatus can print, which may also be referred to herein as the build volume. This means that the multiple 3D objects are placed in the total volume in such a manner that they all fit in the total volume. It is generally desirable to maximize the number of objects in the build volume, while also minimizing the height of the arrangement of objects within the build volume, so as to lower raw material consumption and production costs.

[0024] When printing multiple 3D objects, the 3D design or nesting arrangement to be printed (the nesting arrangement being the 3D objects arranged in 3D as they are to be printed by the additive manufacturing apparatus) can be stored or represented as a digital 3D representation (e.g., CAD, STL, etc.). Objects can be arranged or nested in the build volume manually or automatically, for example using an application such as MAGICS® 3D nesting software.

[0025] FIG. 1 illustrates one example of 3D nesting of a set of 3D objects in a build volume. The leftmost portion of FIG. 1 shows the array of objects that will be printed, and the rightmost portion of FIG. 1 shows the objects nested in the build volume and packed down to lower the build height and increase nesting density.

[0026] FIG. 2A illustrates an example of two motorcycle models displayed next to a build volume. FIG. 2B illustrates an example of a 3D nesting arrangement for the set of 3D objects comprising the motorcycle models of FIG. 2A. As can be seen in FIG. 2B, the individual objects forming part of the models are nested compactly together within the build volume. [0027] Certain types of object shapes can present problems during nesting operations. For example, FIG. 4 illustrates an object forming a hollow bottle 300 which has been nested in a build volume along with spherical objects 304. As can be seen in FIG. 4, the spherical objects 304 have been nested inside the bottle 300 and, as such, will be printed inside the bottle 300 once the build operation commences. If, however, the diameter of the spherical objects 304 is larger than the opening 302 of the bottle 300, the spherical objects 304 will be trapped in the internal cavity of the bottle 300, and it will be impossible to retrieve the spherical objects 304 without breaking the bottle 300.

[0028] FIG. 5 illustrates another example of potentially problematic object shapes for a nesting operation. FIG. 5 shows two objects forming eyeglass frames 400, each of which has two openings 402. Because of these openings 402, if multiples of these eyeglass frames 400 are nested in the same build volume, there is a risk that they will interlock with one another as shown in FIG. 5. If nested in this manner, once printed, it will be impossible to separate the interlocked objects 400 without breaking one or the other.

[0029] According to various embodiments, the nesting arrangement and/or the objects making up that arrangement can be manipulated to solve or avoid any potential trapping or interlocking problems before commencing a print or build operation, thereby improving yield and reducing production costs. In embodiments, once a problematic object (e.g., an object having an opening and/or an internal cavity) is identified, the problematic object can be replaced with a modified version of that object, with any openings, internal cavities, or other problematic features effectively closed or filled to eliminate the potential for trapping or interlocking. FIG. 5 illustrates an example of a modified version 500 of one of the eyeglass frames 400 illustrated in FIG. 4, with openings 402 closed as indicated by reference 502. The modified version 500 can otherwise have the same dimensions as the original version 400. The modified versions of the problematic objections may also be referred to herein as interlock-proof counterparts.

[0030] Once the problematic object or objects are replaced with their corresponding modified versions, the modified set of objects (including the original versions of the non- problematic objects, and modified versions of the problematic or potentially problematic parts) can be nested as desired (e.g., to achieve a suitable nesting density) without any interlocking error conditions such as trapped or interlocked parts. After such nesting, but before the build operation commences, the modified objects can be replaced with their corresponding originals. [0031] With reference now to FIG. 6, an example of a process 600 for solving interlocking error conditions in a 3D nesting arrangement using a computing device is illustrated. At block 602, a first nesting arrangement for a set of objects, including all of the objects to be printed, is determined. The nesting arrangement can be determined automatically, based on the size and shape of the objects to be printed, for example using a 2D or 3D nesting application such as MAGICS® 3D nesting software. In some embodiments, the nesting can be performed with manual direction or intervention by a user using an application on the computing device. While the nesting operation can be performed directly on the objects, in some embodiments, the nesting arrangement can be performed on other virtual representations of the objects, including simplified or parameterized representations of the objects, for example parts with reduced triangles or otherwise reduced complexity, to lower computing resource requirements. For example, in some embodiments, the nesting operation can be performed using volumetric representations of the objects to be printed. It will be understood that the various other analytical operations and manipulations described herein as being performed on "objects" will be understood to mean that the operations can be performed either directly on the objects themselves, or on volumetric or other virtual representations of the objects. Performing these operations on mathematically simpler versions of the objects can significantly improve the speed and efficiency of these operations.

[0032] At block 602, one or more objects meeting an interlocking error condition can be identified. FIGS. 3 and 4 illustrate examples of such objects. In block 602, the objects meeting an interlocking error condition can be identified using an interlocking test, or any other suitable method.

[0033] At block 604, versions of the interlocking objects can be generated which are modified to eliminate or correct any problematic or potentially problematic features such as tunnels or cavities. FIG. 5 illustrates an example of such a modified version. The modified versions can be generated using any suitable method. Although the term "generated" is used to describe the creation of a modified version of an object, it will be understood that generating a modified version does not necessarily require that the modified version is generated for display or is otherwise visible to a user. Instead, the modified version may simply be a transformation of the original object that is used by the computing device to position the object (e.g. to develop a nesting arrangement); any visual display of a nesting arrangement can include the original version or the modified version of an object, as may be desired. [0034] At block 606, a second nesting arrangement can be determined based on a modified set of objects. The modified set of objects can include the original versions of all of the objects in the set, except that any problematic or potentially problematic objects identified in block 602 can be replaced by modified versions thereof, as generated in block 604.

[0035] In some embodiments, the processes at blocks 602 through 606 can be repeated to identify any further objects meeting an interlocking error condition, generate interlock-proof counterparts of these objects, and determine a nesting arrangement based on a modified set of objects, including the newly generated interlock-proof versions of any problematic or potentially problematic objects.

[0036] Also in some embodiments, after block 606, the overall 3D design to be printed can be finalized and sent for manufacture to an additive manufacturing device. Such finalization can include replacing any modified versions of the objects in the second nesting arrangement with their original counterparts (or otherwise restoring the modified versions to their original topological characteristics). A build operation can then be initiated, which will manufacture all of the objects in the set using an additive manufacturing device, without any interlocking or trapped parts. With reference now to FIG. 7, an example of a process 700 for avoiding interlocking error conditions in a 3D nesting arrangement using a computing device is illustrated. At block 702, the process 700 can include generating a modified version of at least one object, the at least one object having a risk characteristic. The risk characteristic can include any topological characteristic which is potentially problematic for a nesting operation, such as, for example, any tunnels (e.g., openings, holes, cavities, or any other like shapes) that might result in trapped or interlocked parts after the nesting operation. In some embodiments, the object or objects having a risk characteristic can be identified manually, with user input identifying the potentially problematic objects being received at the computing device. In other embodiments, the object or objects having a risk characteristic can be identified automatically by the computing device. To identify objects having a risk characteristic, the part geometry can be analyzed using appropriate metrics to detect tunnels, cavities, holes, and any other features that can be problematic and result in trapping or interlocking with other objects. Alternatively, in some embodiments, an object having a risk characteristic can be identified by analyzing a given nesting arrangement and identifying any objects meeting an interlocking error condition. In such an example, any objects meeting an interlocking error condition can be considered to have a risk characteristic. [0037] In some embodiments, modified versions of all of the objects in a set can be generated without first identifying any specific items having a risk characteristic. By generating modified versions of every object in the set, all the objects will become interlock-proof.

[0038] The modified version(s) of the object(s) can be generated using any suitable process to close, fill, or otherwise fix (at least for the purposes of performing the nesting operation) the problematic objects or their problematic features.

[0039] At block 704, a nesting arrangement for the set of objects can be determined based on a modified set of objects. The modified set of objects can include the original versions of all of the objects in the set, except that the modified version of any object generated at block 702 will replace the original version of any object meeting a risk characteristic. In an embodiment in which all of the objects in the set are modified to create interlock-proof counterparts (regardless of whether the original object included a tunnel, cavity, or other risk characteristic), the modified set of objects can include a modified version of each and every object.

[0040] In some embodiments, after block 704, the overall 3D design to be printed can be finalized and sent for manufacture to an additive manufacturing device. Such finalization can include replacing any modified versions of the objects in the nesting arrangement with their original counterparts (or otherwise restoring the modified versions to their original topological characteristics). A build operation can then be initiated, which will manufacture all of the objects in the set using an additive manufacturing device, without any interlocking or trapped parts.

[0041] It should be noted that the processes described herein with respect to certain figures are merely exemplary embodiments, and that some of the blocks and steps of the processes may be performed in a different order, removed, and/or additional blocks and steps added to the processes while still being within the scope of the invention.

[0042] FIG. 8 illustrates one example of a system 1100 for designing and manufacturing object by additive manufacturing, including, for example, 3D designs. The system 1100 may be configured to support the techniques described herein.

[0043] In some embodiments, the system 1100 may include one or more computers 1102a- 1102d. The computers 1102a-l 102d may take various forms such as, for example, any workstation, server, or other computing device capable of processing information. The computers 1102a-l 102d may be connected by a computer network 1105. The computer network 1105 may be, for example, the Internet, a local area network, a wide area network, or some other type of network capable of digital communications between electronic devices. Additionally, the computers 1102a-1102d may communicate over the computer network 1105 via any suitable communications technology or protocol. For example, the computers 1102a-1102d may share data by transmitting and receiving information such as software, digital representations of 3D objects and designs, commands and/or instructions to operate an additive manufacturing device, and the like.

[0044] The system 1100 further may include one or more additive manufacturing devices 1106a and 1106b. These additive manufacturing devices may comprise 3D printers or some other manufacturing device as known in the art. In the example shown in FIG. 8, the additive manufacturing device 1106a is directly connected to the computer 1102d. The additive manufacturing device 1106a is also connected to computers 1102a- 1102c via the network 1105, which further connects computers 1102a-1102d. Additive manufacturing device 1106b is also connected to the computers 1102a-1102d via the network 1105. A skilled artisan will readily appreciate that an additive manufacturing device such as devices 1106a and 1106b may be directly connected to a computer, connected to a computer, and/or connected to a computer via another computer.

[0045] Although a specific computer and network configuration is described in FIG. 8, a skilled artisan will also appreciate that the additive manufacturing techniques described herein may be implemented using a single computer configuration which controls and/or assists the additive manufacturing device 1106, without the need for a computer network.

[0046] FIG. 9 illustrates a more detailed view of computer 1102a illustrated in FIG. 8. The computer 1102a includes a processor 1210. The processor 1210 is in data communication with various computer components. These components may include a memory 1220, an input device 1230, and an output device 1240. In certain embodiments, the processor may also communicate with a network interface card 1260. Although described separately, it is to be appreciated that functional blocks described with respect to the computer 1102a need not be separate structural elements. For example, the processor 1210 and network interface card 1260 may be embodied in a single chip or board.

[0047] The processor 1210 may be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0048] The processor 1210 may be coupled, via one or more data buses, to read information from or write information to memory 1220. The processor may additionally, or in the alternative, contain memory, such as processor registers. The memory 1220 may include processor cache, including a multi-level hierarchical cache in which different levels have different capacities and access speeds. The memory 1220 may further include random access memory (RAM), other volatile storage devices, or non- volatile storage devices. The storage can include hard drives, optical discs, such as compact discs (CDs) or digital video discs (DVDs), flash memory, floppy discs, magnetic tape, Zip drives, USB drives, and others as are known in the art.

[0049] The processor 1210 may also be coupled to an input device 1230 and an output device 1240 for, respectively, receiving input from and providing output to a user of the computer 1102a. Suitable input devices include, but are not limited to, a keyboard, a rollerball, buttons, keys, switches, a pointing device, a mouse, a joystick, a remote control, an infrared detector, a voice recognition system, a bar code reader, a scanner, a video camera (possibly coupled with video processing software to, e.g., detect hand gestures or facial gestures), a motion detector, a microphone (possibly coupled to audio processing software to, e.g., detect voice commands), or other device capable of transmitting information from a user to a computer. The input device may also take the form of a touch-screen associated with the display, in which case a user responds to prompts on the display by touching the screen. The user may enter textual information through the input device such as the keyboard or the touch-screen. Suitable output devices include, but are not limited to, visual output devices, including displays and printers, audio output devices, including speakers, headphones, earphones, and alarms, additive manufacturing devices, and haptic output devices.

[0050] The processor 1210 further may be coupled to a network interface card 1260. The network interface card 1260 prepares data generated by the processor 1210 for transmission via a network according to one or more data transmission protocols. The network interface card 1260 may also be configured to decode data received via the network. In some embodiments, the network interface card 1260 may include a transmitter, receiver, or both. Depending on the specific embodiment, the transmitter and receiver can be a single integrated component, or they may be two separate components. The network interface card 1260, may be embodied as a general purpose processor, a DSP, an ASIC, a FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein.

[0051] FIG. 10 illustrates a general process 1300 for manufacturing an object using an additive manufacturing apparatus, such as 1106a or 1106b in FIG. 8.

[0052] The process begins at step 1305, where a digital representation of the 3D design to be manufactured is designed using a computer, such as the computer 1102a in FIG. 8. In some embodiments, a 2D representation of the device may be used to create a 3D object of the device. Alternatively, 3D data may be input to the computer 1102a for aiding in designing the digital representation of the 3D design. Additionally or alternatively, the 3D design is generated using embodiments of the processes described with respect to FIG. 6 and/or FIG. 7. In some embodiments, the computer 1102a is the computing device described with respect to FIG. 8. The process continues to step 1310, where information is sent from the computer 1102a to an additive manufacturing device, such as additive manufacturing devices 1106a and 1106b. Next, at step 1315, the additive manufacturing device begins manufacturing the 3D device by performing an additive manufacturing process using suitable materials, as described above. Using the appropriate materials, the additive manufacturing device then completes the process at step 1320, where the 3D object is completed.

[0053] Various specific additive manufacturing techniques may be used to produce objects using a method like that shown in FIG. 10. As explained above, these techniques include SL, LS, and SLM, among others.

[0054] With reference now to FIG. 11, a computer-based system 1400 for 3D printing a set of objects according to an embodiment is illustrated. The system 1400 may be comprised of one or more computers such as computer 1102a discussed above. The system 1400 can include a nesting module 1402 which may be configured to perform various functions within the system 1400, such as, for example, generating a modified version of at least one object, the at least one object having a risk characteristic. The nesting module 1402 can be further configured to determine a nesting arrangement for the set of objects based on a modified set of objects, the modified set including the modified version of the at least one object having a risk characteristic such as, for example, a tunnel or a cavity. As illustrated in FIG. 11, the system 1400 may optionally also include an analysis module 1404 which is configured to identify at least one object having a risk characteristic. The nesting module 1402 and the optional analysis module 1404 may be comprised primarily or entirely of software, or they may be comprised of a combination of hardware and software, or in still other embodiments, specialized hardware such as ASIC or other types of microprocessors. In some embodiments, certain nesting and/or analysis functionality may be provided by one software application, while other nesting and/or analysis functionality can be provided by one or more separate computer applications. Alternatively, all of these functionalities may be provided in a single computer program.

[0055] The embodiments disclosed herein may be implemented as a method, apparatus, or article of manufacture using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term "article of manufacture" as used herein refers to code or logic implemented in hardware or non-transitory computer readable media such as optical storage devices, and volatile or non-volatile memory devices or transitory computer readable media such as signals, carrier waves, etc. Such hardware may include, but is not limited to, FPGAs, ASICs, complex programmable logic devices (CPLDs), programmable logic arrays (PLAs), microprocessors, or other similar processing devices.

[0056] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention without departing from the spirit or the scope of the invention as broadly described. The above described embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

WHAT IS CLAIMED IS:

1. A method for improved 3D printing of a set of objects, the method comprising: determining a first nesting arrangement for the set of objects;

identifying at least one object meeting an interlocking error condition;

generating a modified version of the at least one object meeting an interlocking error condition; and

determining a second nesting arrangement based on a modified set of objects, the modified set including the modified version of the at least one object meeting an interlocking error condition.

2. The method of Claim 1, further comprising:

identifying at least a second object meeting an interlocking error condition;

generating a modified version of the at least second object meeting an interlocking error condition; and

determining a third nesting arrangement based on a second modified set of objects, the second modified set of objects including the modified version of the at least one object meeting an interlocking error condition and the modified version of the at least second object meeting an interlocking error condition.

3. A method for improved 3D printing of a set of objects, the method comprising: generating a modified version of at least one object, the at least one object having a risk characteristic; and

determining a nesting arrangement for the set of objects based on a modified set of objects, the modified set including the modified version of the at least one object having a risk characteristic.

4. The method of Claim 3, wherein the risk characteristic comprises at least one of a tunnel or a cavity.

5. The method of Claim 3, further comprising receiving input identifying the at least one object having a risk characteristic.

6. The method of Claim 3, further comprising identifying the at least one object having a risk characteristic.

7. The method of Claim 3, further comprising identifying at least one object meeting an interlocking error condition.

8. The method of Claim 3, further comprising replacing the modified version of the at least one object with an original version of the at least one object.

9. A system for 3D printing a set of objects, the system comprising:

a nesting module configured to generate a modified version of at least one object, the at least one object having a risk characteristic, the nesting module being further configured to determine a nesting arrangement for the set of objects based on a modified set of objects, the modified set including the modified version of the at least one object having a risk characteristic.

10. The system of Claim 9, further comprising an analysis module, the analysis module being configured to identify at least one object having a risk characteristic.

11. The system of Claim 10, wherein the risk characteristic comprises at least one of a tunnel or a cavity.