Systems and methods for detecting failed bed adhesion of a three-dimensional printer

Abstract

A 3D printer (100) includes: a housing (102) defining a chamber (104); and printing surfaces (108, 208, 308, 408) disposed within the chamber (104). The printer also includes a nozzle (128) displaceable relative to the printing surfaces (108, 208, 308, 408) for melting and distributing the filament (124) onto the printing surfaces (108, 208, 308, 408) during printing to form dielectric parts (130). The printer further includes: a filament drive system (126) for supplying the filament (124) to the nozzle (128); and one or more capacitive sensors (134, 234, 334, 434) coupled to the printing surfaces (108, 208, 308, 408). The printer also includes a controller (152) electrically connected to the capacitance sensors (134, 234, 334, 434) for measuring capacitance. During printing, the controller (152) generates an error signal in response to determining a change in capacitance as the dielectric component (130) shifts relative to the printing surface (108, 208, 308, 408). The printer also includes a display device (156) electrically connected to the controller (152) and displays an error message in response to receiving an error signal.

Description

Technical Field

[0001] This disclosure relates to a 3D printer for printing parts on a print bed, and more specifically to a system and method for detecting failed adhesion between a part and a print bed. Background Technology

[0002] A 3D printer produces three-dimensional parts based on a computer-generated model. During additive manufacturing, the printer deposits raw material onto a print bed. In some cases, a filament may be included in the print head, which draws the raw material in the form of thermoplastic filaments from a spool contained within a canister. The print head may move along a path while heating the filament and depositing it onto the print bed to form a part. For example, the print head may move in the XY plane and deposit the filament in a first layer, and the print head and / or print bed may move along the Z-axis to form successive layers. This process can then be repeated until the entire part is completed.

[0003] An exemplary challenge in additive manufacturing is that parts may detach from the print bed, and the print head may drag the part along the print bed before the entire part is printed. Adhesion failure between the part and the print bed can cause the printed part to deviate from the design requirements, which in turn requires the part to be reprinted and wastes material.

[0004] Therefore, although current 3D printers have achieved their intended purpose, a new and improved 3D printer is still needed to solve these problems. Summary of the Invention

[0005] This disclosure provides a 3D printer including a housing defining a chamber and a printing surface disposed within the chamber. The printer also includes a nozzle displaceable relative to the printing surface for melting and distributing a filament onto the printing surface during printing to form a dielectric part. The printer further includes a filament driving system for supplying the filament to the nozzle, and one or more capacitance sensors coupled to the printing surface. The printer also includes a controller electrically coupled to the capacitance sensors for measuring capacitance during printing. The controller determines a change in capacitance in response to displacement of the dielectric part relative to the printing surface during printing. The controller generates an error signal in response to determining the change in capacitance. The printer also includes a display device electrically coupled to the controller and displays an error message in response to receiving an error signal from the controller.

[0006] This disclosure also provides a 3D printer including a housing defining a chamber. The printer also includes a printing surface disposed within the chamber and having multiple segments. The printer further includes nozzles displaceable relative to the printing surface for melting and distributing filaments onto those segments of the printing surface during printing to form at least one dielectric part. The printer also includes a filament driving system for supplying filaments to the nozzles, and multiple capacitive sensors coupled to associated segments of the printing surface. The printer also includes a controller electrically coupled to the multiple capacitive sensors for measuring the capacitance of associated segments of the printing surface during printing. The controller determines a change in capacitance in response to displacement of associated portions of the dielectric part relative to associated segments of the printing surface during printing. The controller generates an error signal in response to detecting a change in capacitance. The printer also includes a display device electrically coupled to the controller and displays an error message in response to receiving an error signal from the controller.

[0007] This disclosure also provides a method for operating a 3D printer, the 3D printer having: a housing; a printing surface disposed within the housing; a nozzle; a filament drive system; at least one capacitance sensor; a controller electrically connected to the capacitance sensor; and a display device. The method includes the filament drive system supplying filaments to the nozzle. The nozzle is displaced relative to the printing surface to melt the filaments during printing and distribute them onto the printing surface to form dielectric parts on the printing surface. The controller and the capacitance sensor measure capacitance during printing. The controller determines a change in capacitance in response to the displacement of the dielectric parts relative to the printing surface during printing. The controller generates an error signal in response to the determined change in capacitance. In response to receiving the error signal from the controller, the display device displays an error message.

[0008] Other features and advantages of this disclosure will become readily apparent and better understood after reading the following description in conjunction with the accompanying drawings. Attached Figure Description

[0009] The advantages of this disclosure will become readily apparent and better understood when considered in conjunction with the accompanying drawings and by referring to the following detailed description.

[0010] Figure 1 This is a perspective view of a 3D printer, showing a printer with a housing that defines a chamber and a print bed disposed within the chamber;

[0011] Figure 2 yes Figure 1 A plan view of the printing bed, showing a printing bed with a single capacitive sensor having multiple fingers;

[0012] Figure 3 yes Figure 2 A cross-sectional view of a printing bed is shown, showing a printing bed having a substrate and composite layers on opposite sides of the substrate, wherein a capacitive sensor is embedded in the substrate, and one of the composite layers has a printing surface on which one or more parts are printed.

[0013] Figure 4 yes Figure 1 A plan view of another example of a print bed, showing a print bed with a single capacitive sensor in the form of an in-plane positive electrode plate and a negative electrode plate;

[0014] Figure 5 yes Figure 1 A plan view of another example of a print bed shows a print bed with multiple capacitive sensors arranged in a matrix in the form of in-plane positive and negative electrode plates, with multiple parts printed on the print surface;

[0015] Figure 6 yes Figure 1 A plan view of another example of a print bed shows a print bed with multiple capacitive sensors arranged in a matrix in the form of in-plane positive and negative electrode plates, with individual parts supported on the print surface.

[0016] Figure 7 It is an operation Figure 1 A flowchart of an exemplary method for using a 3D printer. Detailed Implementation

[0017] The following description is merely exemplary in nature and is not intended to limit this disclosure, application, or use.

[0018] refer to Figure 1 An example of a 3D printer 100 includes a housing 102 defining a chamber 104 and a print bed 106 disposed within the chamber 104. The print bed 106 has a section 110 ( Figure 2 and Figure 3 The printing surface 108 of the composite board 110 is on which the dielectric component 130 is printed. In this example, the print bed 106 is the composite board 112. Figure 2 and Figure 3 The printer 100 includes a substrate 114 disposed between two composite layers 116 and 118, wherein one of the composite layers 116 and 118 includes a printing surface 108. The substrate 114 and the composite layers 116 and 118 may be made of a glass fiber-epoxy laminate. In other examples, the print bed may be made of other materials and have any number of layers. The printer 100 also includes a Z-motor system 120 for linearly moving the printing surface 108 along the Z-axis.

[0019] The printer 100 also includes one or more reservoirs 122 for storing filaments 124 and a filament drive system 126 for drawing one or more filaments 124 from the associated reservoirs 122. Although Figure 1 The diagram shows a filament drive system 126 drawing only one filament 124 from a single container, but it is conceivable that the filament drive system 126 could engage two or more filaments dispensed from any number of containers 122. Other examples of printers may include additional delivery mechanisms for delivering filament or non-filament material from any suitable storage device to the printing surface.

[0020] Printer 100 also includes a nozzle 128 for receiving a filament 124 from a filament drive system 126, heating the filament 124, moving it relative to the printing surface 108, and distributing the filament 124 onto one or more segments 110 of the printing surface 108 during printing to form one or more dielectric parts 130. Printer 100 includes an XY fully linear motor system 132 for moving the nozzle 128 in the XY plane to print the dielectric parts 130 on the printing surface 108. However, it is contemplated that one or both of the nozzle 128 and the printing surface can move in any suitable direction to 3D print the parts 130.

[0021] Refer again Figure 2 and Figure 3 The printer 100 also includes one or more capacitive sensors 134 coupled to the printing surface 108. In this example, the printer 100 includes a capacitive sensor 134 coupled to a segment 110 of the printing surface 108. The capacitive sensor 134 is electrically coupled to a voltage source 136 having a positive terminal 138 and a negative terminal 140. The capacitive sensor 134 also includes a positive electrode 142 coupled to and receiving a positive charge from the positive terminal 138. Each capacitive sensor 134 also includes a negative electrode 144 coupled to and receiving a negative charge from the voltage source 136. It is conceivable that the printer may include more than one capacitive sensor, such as... Figure 5 and Figure 6 As detailed in the description of the example shown.

[0022] like Figure 2 As best shown in the diagram, the positive electrode 142 and the negative electrode 144 each include a plurality of fingers 148, 150 embedded within the substrate 114, wherein the fingers 148 of the positive electrode 142 and the fingers 150 of the negative electrode 144 alternate. However, it is conceivable that the printer may include any number of capacitors in the form of fingers, in-plane plates, or other suitable structures arranged in series or parallel.

[0023] Return to reference Figure 1The printer 100 also includes a controller 152 electrically connected to a filament drive system 126, an XY motor system 132, a nozzle 128, and a Z motor system 120 for actuating them to 3D print the dielectric part 130. The controller 152 is also electrically connected to a capacitance sensor 134 for measuring the capacitance of an associated segment 110 of the printing surface 108 during printing. In this example, the controller 152 includes an analog-to-digital converter 154 connected to the capacitance sensor 134 for converting the capacitance into a voltage and then into a digital value. The controller 152 determines a change in capacitance in response to displacement of the associated portion of the dielectric part 130 relative to the associated segment 110 of the printing surface 108 during printing. The controller 152 generates an error signal in response to detecting a change in capacitance. More specifically, the controller 152 is configured to generate an error signal in response to determining that the change in capacitance exceeds a predetermined threshold. The threshold may be a value determined empirically. For example, the threshold could be 20 picofarads, where controller 152 and associated capacitance sensor 134 measure a capacitance of 120-140 picofarads when the dielectric part adheres to the associated segment 110 of print surface 108, and a capacitance of 100 picofarads when the dielectric part separates from and moves relative to the associated segment 110 of print surface 108. While it is conceivable that the threshold could be higher or lower than 20 picofarads, and the feedstock and print bed could be made of any suitable material having an associated capacitance value in the range of 120-140 picofarads, controller 152 still determines the change in capacitance in response to the part separating from the print bed. Controller 152 is configured not to generate an error signal in response to controller 152 determining that the change in capacitance is less than a predetermined threshold. In response to the filament drive system 126 receiving an error signal from controller 152, filament drive system 126 stops supplying filament to nozzle 128.

[0024] like Figure 1 As shown, printer 100 also includes a display device 156 electrically connected to controller 152 for displaying an error message in response to receiving an error signal from controller 152. A technician can inspect part 130 for any defects associated with failed bed adhesion and determine whether such defects are repairable.

[0025] Printer 100 also includes a user interface 158 for generating continue and stop command signals. In response to a technician determining that the defect in part 130 associated with an error signal is repairable, the technician can operate user interface 158 to generate a continue command signal. Controller 152 can receive a continue signal from user interface 158, causing the filament drive system 126, nozzle, XY motor system 132, and Z motor system to continue printing part 130 in response to receiving the continue command signal from user interface 158. Furthermore, the technician can operate user interface 158 to generate a stop command signal. Controller 152 can receive a full stop signal from user interface 158, causing the filament drive system 126, nozzle, XY motor system 132, and Z motor system 120 to stop printing all parts.

[0026] refer to Figure 4 Another example of print bed 206 is similar. Figure 2 The printing bed 106, and includes similar parts identified by the same reference numerals followed by 100. However, Figure 2 Print bed 106 includes a capacitive sensor 134 having a positive electrode 142 and a negative electrode 144 in the form of alternating fingers 148 and 150, while print bed 206 includes a single capacitive sensor 234 having a positive electrode 242 and a negative electrode 244 in the form of in-plane electrode plates positioned adjacent to each other within a substrate. Print surface 208 includes a seam 260 between the positive electrode 242 and the negative electrode 244, such that dielectric filaments formed across the seam 260 generate associated capacitance.

[0027] refer to Figure 5 Another example of print bed 306 is similar. Figure 2 The printing bed 106, and includes similar parts identified by the same reference numerals plus 200. However, Figure 2The print bed 106 has a single segment 110 of the print surface 108 and a single capacitive sensor 134 having a positive electrode 142 and a negative electrode 144 in the form of alternating fingers 148, 150. However, the print bed 306 includes multiple segments 310 having multiple capacitive sensors 334 arranged in a matrix 362, wherein each capacitive sensor 334 has a positive electrode 342 and a negative electrode 344 in the form of adjacent in-plane electrode plates embedded in a substrate. The positive electrode 342 and the negative electrode 344 meet at an associated seam 360, causing individual parts 330a-330d formed on the associated seam 360 to generate an associated capacitance. In this example, each capacitive sensor 334 is directly electrically connected to a voltage source 336 in a series circuit, allowing the controller to determine changes in capacitance of the associated segment of the print surface 308 and to determine bed adhesion failure of a particular part. In another example, capacitive sensors are arranged in a parallel circuit, where the positive electrode of each sensor is connected to a positive terminal, and the negative electrode of each sensor is connected to a negative terminal. For example, as... Figure 6 As shown, the row of positive electrodes 442 can be connected in parallel to voltage source 136, and the column of negative electrodes 444 can be connected in parallel to voltage source 136. It is conceivable that the capacitive sensor matrix can be arranged in any suitable circuit.

[0028] In this example, the printer includes a user interface 158 for generating a full continue command signal, a partial stop command signal, and a full stop command signal. In response to a technician determining that the defect in part 130 associated with the error signal is repairable, the technician can operate the user interface 158 to generate a full continue command signal. The controller 152 can receive the full continue signal from the user interface 158, causing the filament drive system 126, nozzle, XY motor system 132, and Z motor system to continue printing all parts in response to receiving the full continue command signal from the user interface 158. Furthermore, in response to a technician determining that the defect associated with the error signal is unrepairable, the technician can also operate the user interface 158 to generate a partial stop command signal. The controller 152 can receive the partial stop signal from the user interface 158 and thereby cause the filament drive system 126, nozzle, XY motor system 132, and Z motor system to stop printing only the parts associated with the error signal and continue printing parts not associated with the error signal. Additionally, the technician can operate the user interface 158 to generate a full stop command signal. The controller 152 can receive a full stop signal from the user interface 158 to cause the filament drive system 126, nozzle, XY motor system 132 and Z motor system 120 to stop printing all parts.

[0029] refer to Figure 6 Another example of print bed 406 is similar. Figure 5The printing bed 306, and includes similar parts identified by the same reference numerals followed by 100. However, Figure 5 The print bed 306 includes multiple capacitance sensors 334 for detecting the capacitance of multiple individual parts 330 of the associated segment 310 adhered to the print surface 308, and multiple capacitance sensors 434 for detecting the capacitance of individual parts 430 of the multiple segments 410 adhered to the print surface CC.

[0030] Now for reference Figure 7 The operation band is shown. Figure 6 Printing bed 406 Figure 1 An example of method 500 for printer 100. Method 500 begins at block 502, wherein a filament drive system 126 supplies filament 124 to nozzle 128. In this example, the filament drive system 126 draws one or more filaments 124 from an associated tank 122 and supplies the filaments 124 to nozzle 128. In other examples, other devices may draw any form of material from any suitable storage container to the nozzle.

[0031] At frame 504, the XY motor system 132 displaces the nozzle 128 relative to the printing surface 108 along the X and Y axes to melt each layer of filament 124 and distribute it onto one or more segments of the printing surface 108, and when each layer is complete, the Z motor system 120 moves the print bed 106 relative to the nozzle 128 along the Z axis to form dielectric parts 130 on the printing surface 108. In this example ( Figure 6 In this example, a single dielectric component 430 is formed on a print bed 406 and includes a first segment 431a and a second segment 431b printed on associated first segments 410a and second segments 410b on a print surface 408. In another example ( Figure 5 Individual dielectric components 330 can be formed on associated segments 310a, 310b of the printing surface 308. Furthermore, it is conceivable that the print bed can be held in a fixed position, and the nozzle can move along the X, Y, and Z axes. It is also conceivable that the nozzle and print bed can move relative to each other, wherein either the nozzle or the print bed can move or remain in a fixed position in any suitable direction.

[0032] At box 506, controller 152 and capacitance sensor measure the capacitance of the associated segment of the printed surface during printing. In one example ( Figure 6A first capacitance sensor 434a measures the capacitance associated with a first segment 410a of the printing surface 408, and a second capacitance sensor 434b measures the capacitance associated with a second segment 410b of the printing surface 408. At each segment 410a, 410b, the capacitance between the positive electrode 442 and the negative electrode 444 is higher when the dielectric part 430 is adhered to the seam 460 than when the dielectric part 430 is separated from or spaced apart from the seam 460. For example, the measured capacitance may be 120-140 picofarads when portions 431a, 431b of the dielectric part 430 are adhered to the associated seam 460, and the measured capacitance may be 100 picofarads when portions 431a, 431b of the dielectric part 430 are separated from or spaced apart from the associated seam 460. It is conceivable that when the dielectric component adheres to the seam, the measured capacitance may be higher or lower than 120-140 picofarads, and when the dielectric component is separated from or spaced from the seam 460, the measured capacitance may be higher or lower than 100 picofarads.

[0033] At block 508, controller 152 compares the capacitance measured at each segment 410a, 410b of the printed surface 408 with the previously measured capacitance at the same segment to detect a change in capacitance when the associated portions 431a, 431b of the dielectric component 430 are displaced relative to the associated segments 410a, 410b of the printed surface 408. If controller 152 determines that the capacitance of each of the first segment 410a and the second segment 410b has changed, the method proceeds to block 510. Continuing the previous example, if controller 152 determines that the capacitance of the first segment 410a and the second segment 410b ( Figure 6 If the capacitance change of each of the two individual dielectric parts 330a and 330b is equal to that of the first segment 410a and the second segment 410b relative to the printing surface 408, then the controller 152 determines that the individual entire dielectric part 430 has shifted relative to the first segment 410a and the second segment 410b of the printing surface 408, and the method proceeds to block 510. In another example, the controller 152 may determine that during the printing process, the two individual parts 330a and 330b ( Figure 5 The method proceeds to block 510 relative to the associated first segment 310a and second segment 310b. If controller 152 determines that the capacitance of both the first segment and the second segment of the printed surface has not changed, the method proceeds to block 522. Continuing with the previous example, if controller 152 determines that the capacitance change of at least one of the first segment 410a and the second segment 410b is below a capacitance change threshold, the method may proceed to block 516.

[0034] At frame 510, controller 152 generates an error signal indicating that one or more dielectric parts have completely separated from the printed surface. More specifically, the error signal may indicate part 430 previously printed on both first segment 410a and second segment 410b. Figure 6 The part 330a, 330b has been separated from or displaced relative to the first segment 410a and the second segment 410b of the printed surface 408. In another example, the error signal may indicate that two separate dielectric parts 330a, 330b (previously printed on the associated segments of the first segment 310a and the second segment 310b of the printed surface 308) have been separated from or displaced relative to the first segment 410a and the second segment 310b of the printed surface 308. Figure 5 It has been separated from the first segment 310a and the second segment 310b and shifted relative to the first segment 310a and the second segment 310b.

[0035] At frame 512, in response to the filament drive system 126 receiving an error signal from the controller 152, the filament drive system 126 stops supplying filament 124 to the nozzle 128.

[0036] At box 514, display device 156 displays an error message to notify technicians of individual dielectric component 430. Figure 6 ) is completely separated from the first segment 410a and the second segment 410b of the printed surface 408, or multiple individual parts 330 ( Figure 5 Separate from the associated segments 310a and 310b of the printed surface 308.

[0037] At box 516, the technician examines the component associated with the notification displayed on display device 156. If the technician determines that the component associated with the error signal has a repairable defect, the process proceeds to box 518. If the technician determines that the component associated with the error signal has an irreparable defect, the process proceeds to box 520.

[0038] At box 518, the technician operates user interface 158 to continue the printing process of the single part 430 associated with the error signal. In another example where printer 100 is printing multiple parts simultaneously, the technician operates user interface 158 to continue the printing process of all parts 330a, 330b, including parts with repairable defects associated with the error signal and parts not associated with the error signal.

[0039] At box 520, the technician operates user interface 158 to terminate the printing process of a single part 430 associated with an error signal. In another example, where printer 100 is printing multiple parts 330a, 330b simultaneously, the technician operates user interface 158 to terminate the printing process of parts associated with error signals and resume the printing process of parts not associated with error signals.

[0040] At block 522, when one of the first portion 431a and the second portion 431b of the dielectric component 430 shifts relative to the print surface 108 during printing, controller 152 determines that one of the changes in the first and second capacitances associated with the first portion 431a and the second portion 431b of the print surface 408 is higher than a capacitance change threshold, and the method proceeds to block 518. If controller 152 determines that the capacitance changes of each of the first segment 410a and the second segment 410b are lower than the capacitance change threshold, the method returns to block 502.

[0041] At frame 524, controller 152 generates an error signal indicating that a portion of a single dielectric part 130 has separated from segments 110a, 110b of the print surface 408 associated with the error signal. In another example where multiple parts 330a, 330b are being printed, the error signal may indicate that multiple parts 330a, 330b have separated from their associated segments 410a, 410b of the print surface 408.

[0042] At frame 526, in response to the filament drive system 126 receiving an error signal from the controller 152, the filament drive system 126 stops supplying filament 124 to the nozzle 128.

[0043] At box 528, display device 156 displays an error message to notify a technician that a single dielectric part 430 has partially separated from the printed surface 408, or in another example, to indicate that multiple individual parts 330a, 330b have separated from their associated segments 410a, 410b of the printed surface 408.

[0044] At box 530, the technician examines the component associated with the notification displayed on display device 156. If the technician determines that the component associated with the error signal has a repairable defect, the process proceeds to box 532. If the technician determines that the component associated with the error signal has an irreparable defect, the process proceeds to box 534.

[0045] At box 532, the technician operates user interface 158 to continue the printing process of the single part 430 associated with the error signal. In another example where printer 100 is printing multiple parts simultaneously, the technician operates user interface 158 to continue the printing process of all parts 330a, 330b, including parts with repairable defects associated with the error signal and parts not associated with the error signal.

[0046] At box 532, the technician operates user interface 158 to terminate the printing process of a single part 430 associated with an error signal. In another example where printer 100 is printing multiple parts 330a, 330b simultaneously, the technician operates user interface 158 to terminate the printing process of parts associated with error signals and resume the printing process of parts not associated with error signals.

[0047] The description in this disclosure is exemplary in nature only, and variations thereof are intended to be made without departing from the general meaning of this disclosure. Such variations should not be considered as departing from the spirit and scope of this disclosure.

Claims

1. A three-dimensional printer (100), comprising: a housing (102) defining a chamber (104); a print surface (108, 208, 308, 408) disposed within the chamber (104); a nozzle (128) displaceable relative to the print surface (108, 208, 308, 408) for melting a filament (124) during a printing process and dispensing the filament (124) on the print surface (108, 208, 308, 408) to form a dielectric part (130); a filament drive system (126) for supplying the filament (124) to the nozzle (128); at least one capacitive sensor (134, 234, 334, 434) coupled to the print surface (108, 208, 308, 408); a controller (152) electrically coupled to the at least one capacitive sensor (134, 234, 334, 434) for measuring a capacitance during the printing process, the controller (152) determining a change in capacitance in response to displacement of the dielectric part (130) relative to the print surface (108, 208, 308, 408) during the printing process, and the controller (152) generating an error signal in response to the controller (152) determining the change in capacitance; and a display device (156) electrically coupled to the controller (152) and displaying an error message in response to the display device (156) receiving an error signal from the controller (152). The filament drive system (126) is electrically coupled to the controller (152) and, in response to the filament drive system (126) receiving the error signal from the controller (152), the filament drive system (126) stops supplying filament (124) to the nozzle (128).

2. The three-dimensional printer (100) of claim 1, wherein The controller (152) is configured to generate the error signal in response to the controller (152) determining that the change in capacitance is above a pre-set threshold.

3. The three-dimensional printer (100) according to claim 2, wherein The controller (152) is configured to not generate the error signal in response to the controller (152) determining that the change in capacitance is less than the pre-set threshold.

4. The three-dimensional printer (100) according to claim 3, wherein and a display device (156), the method (500) comprising:

5. A method (500) of operating a three-dimensional printer (100), the printer having: a housing (102); a print surface (108, 208, 308, 408) disposed within the housing (102); a nozzle (128); a filament drive system (126); at least one capacitive sensor (134, 234, 334, 434); a controller (152) electrically coupled to the at least one capacitive sensor (134, 234, 334, 434); supplying filament (124) to the nozzle (128) by the filament drive system (126); displacing the nozzle (128) relative to the print surface (108, 208, 308, 408) for melting and dispensing the filament (124) during a printing process to form a dielectric part (130) on the print surface (108, 208, 308, 408); measuring a capacitance during the printing process by the controller (152) and the at least one capacitive sensor (134, 234, 334, 434); ​ During the printing process, determining, by the controller (152), a change in capacitance in response to the dielectric part (130) being displaced relative to the print surface (108, 208, 308, 408); generating, by the controller (152), an error signal in response to the controller (152) determining the change in capacitance during the printing process; and displaying, by the display device (156), an error message in response to the display device (156) receiving the error signal from the controller (152).

6. The method (500) of claim 5, further comprising the filament drive system (126) stopping the supply of the filament (124) to the nozzle (128) during the printing process in response to the filament drive system (126) receiving the error signal from the controller (152).

7. The method (500) of claim 6, further comprising the controller (152) generating the error signal in response to the controller (152) determining that the change in capacitance is above a pre-set threshold.

8. The method (500) of claim 7, further comprising the controller (152) not generating the error signal in response to the controller (152) determining that the change in capacitance is below the pre-set threshold.

9. The method (500) of claim 5, further comprising: measuring the capacitance associated with a first portion and a second portion of the print surface (108, 208, 308, 408) during the printing process; determining, by the controller (152), one of a first change and a second change in capacitance associated with the first portion and the second portion of the print surface (108, 208, 308, 408) in response to a portion of the dielectric part (130) being displaced relative to the print surface (108, 208, 308, 408) during the printing process; and generating, by the controller (152), the error signal indicating a partial separation of the dielectric part (130) in response to the controller (152) determining that one of the first change and the second change in capacitance is above a change in capacitance threshold.

10. The method (500) of claim 9, further comprising: determining, by the controller (152), a common change in capacitance associated with the first portion and the second portion of the print surface (108, 208, 308, 408) in response to the entire dielectric part (130) being displaced relative to the print surface (108, 208, 308, 408) during the printing process; and generating, by the controller (152), the error signal indicating a complete separation of the dielectric part (130) in response to the controller (152) determining the common change in capacitance associated with the first portion and the second portion of the print surface (108, 208, 308, 408). ​ ​

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