Fused deposition modeling 3D printer

Abstract

A fused deposition modeling 3D printer includes an extrusion module and a pressure sensor. The extrusion module includes an outer frame, an extrusion mechanism and at least one hot end. The extrusion mechanism is disposed in the outer frame and includes a first gear. The first gear and the hot end are used to extrude and push a wire for fused deposition modeling. The pressure sensor is disposed between the outer frame and the extrusion mechanism. The pressure sensor is used to sense the pressure value of the extrusion module when extruding and pushing the wire. Through real-time pressure sensing, the troubleshooting can be accelerated, and the process of extruding the wire is more accurate and stable.

Description

Technical Field

[0001] This disclosure relates to a fused deposition modeling 3D printer. Background Technology

[0002] In a 3D printer that utilizes fused deposition modeling (FDM), filament is fed into the hot end and heated to a molten state. The molten material is then extruded through the nozzle of the hot end and deposited layer by layer onto the printing platform. It is then rapidly cooled and solidified, and finally combined with the material already deposited on the printing platform to construct a complete 3D structure.

[0003] However, during the printing process, filament may become clogged at the hot end or jammed in the feed path. If this abnormality is not detected and resolved in time, the 3D printer may continue to run idle until the printing job is completed. This not only leads to printing failures but also continuously consumes time, energy, and filament. Utility Model Content

[0004] In view of this, one object of this disclosure is to provide a fused deposition modeling 3D printer that can solve the above-mentioned problems.

[0005] One aspect of this disclosure relates to a fused deposition modeling (FDM) 3D printer, including an extrusion module and a pressure sensor. The extrusion module includes a frame, an extrusion mechanism, and at least one hot end. The extrusion mechanism is disposed within the frame and includes a first gear. The first gear and the hot end are used to extrude and push filament for fused deposition modeling. The pressure sensor is disposed between the frame and the extrusion mechanism. The pressure sensor is used to sense the pressure value of the extrusion module when extruding and pushing the filament.

[0006] In some embodiments, the extrusion module further includes a rotating structure disposed within an outer frame and having a plurality of perforations, each perforation configured to allow wire to pass through, and the perforations being arranged about an axis, wherein a hot end is located below the rotating structure and each hot end is aligned with one of the perforations, thereby receiving the wire at the hot end, wherein the extrusion mechanism further includes a second gear, wherein the first gear and the second gear are configured to mesh with each other and rotate toward each other to push the wire located between the first gear and the second gear.

[0007] In some embodiments, the extrusion mechanism further includes an inner frame disposed within the outer frame and including a first gear housing portion and a second gear housing portion, wherein the first gear and the second gear are respectively disposed in the first gear housing portion and the second gear housing portion.

[0008] In some embodiments, the extrusion module further includes two elastic members that connect the first gear receiving portion and the second gear receiving portion to the outer frame, respectively, and the two elastic members are configured to apply force to the first gear receiving portion and the second gear receiving portion, respectively.

[0009] In some embodiments, the extrusion module further includes a cam structure disposed between the outer frame and the inner frame, and the cam structure is configured to apply force to the first gear and the second gear.

[0010] In some embodiments, the extrusion module further includes a rotating structure having a central shaft and a plurality of through holes. The rotating structure is rotatably connected to the outer frame via the central shaft. The through holes are arranged around the central shaft and configured to allow wire to pass through. A hot end is located below the rotating structure, and each hot end is aligned with one of the through holes so that the hot end receives the wire. The extrusion mechanism further includes an idler wheel located in the rotating structure. A first gear is located on one side of the rotating structure. The idler wheel and the first gear are configured to rotate in opposite directions to squeeze and push the wire between the idler wheel and the first gear.

[0011] In some embodiments, the outer frame has a connecting portion extending from above the top of the rotating structure to below the bottom, and the two ends of the connecting portion are respectively connected to the two ends of the central shaft.

[0012] In some embodiments, the extrusion module further includes a worm gear reducer located above the rotating structure and connected to the central shaft, the worm gear reducer being configured to rotate or lock the rotating structure.

[0013] In some embodiments, the fused deposition modeling 3D printer further includes a linear guide rail assembly, wherein the extrusion module is disposed on the linear guide rail assembly, and the linear guide rail assembly has protrusions.

[0014] In some embodiments, the extrusion module further includes a rotating structure connected to the first gear and the outer frame. When the extrusion module contacts the protrusion, the protrusion applies force to the rotating structure, thereby moving the first gear away from the outer frame.

[0015] These and other aspects of this disclosure will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, but variations and modifications may be made therein without departing from the spirit and scope of the novel concept of this disclosure. Attached Figure Description

[0016] The accompanying drawings illustrate one or more embodiments of this disclosure and, together with the written description, serve to explain the principles of this disclosure, wherein:

[0017] Figure 1 and Figure 2 This is a perspective view of a fused deposition modeling 3D printer according to some embodiments of the present disclosure.

[0018] Figures 3 to 6 This is a perspective view of some components of a fused deposition modeling 3D printer according to some embodiments of the present disclosure.

[0019] Figure 7A , Figure 7B , Figure 8A and Figure 8B This is a cross-sectional schematic diagram of some components of a fused deposition modeling 3D printer according to some embodiments of the present disclosure.

[0020] Figure 9 This is a perspective view of a fused deposition modeling 3D printer according to some embodiments of the present disclosure.

[0021] Figure 10 and Figure 11 This is a perspective view of some components of the extrusion module of a fused deposition modeling 3D printer according to some embodiments of the present disclosure.

[0022] Figures 12 to 14 The following are side view, top view and perspective view of a fused deposition modeling 3D printer according to some embodiments of the present disclosure.

[0023] Symbol Explanation

[0024] 10, 20, 30: Fused Deposition Modeling 3D Printers

[0025] 100, 200, 300: Extrusion modules

[0026] 102,202,302: Outer frame

[0027] 104, 208, 308: Extrusion mechanism

[0028] 106, 206, 306: Hot end

[0029] 108, 218, 318: First gear

[0030] 110,220: Second gear

[0031] 112,210: Inner frame

[0032] 114,222,322: Drive unit

[0033] 116,230,328: Pressure sensor

[0034] 204, 304: Rotational Structure

[0035] 212: Spindle

[0036] 214: First Gear Storage Section

[0037] 216: Second gear storage section

[0038] 224, 226: Elastic components

[0039] 228: Cam Structure

[0040] 310: Central axis

[0041] 312: Connecting part

[0042] 320: Idle Gear

[0043] 324: Worm Gear Reducer

[0044] 326: Rotational Structure

[0045] 326a: Fixed shaft

[0046] 326b: Rotary lever

[0047] 350: Linear guide rail assembly

[0048] 352: Slide rail

[0049] 354: Protrusion

[0050] A: Axis

[0051] A-A',B-B': line segment

[0052] BP: Bottom

[0053] F: Wire

[0054] H: Perforation

[0055] R: Groove

[0056] SP: Side

[0057] TP: Top

[0058] X, Y, Z: Direction Detailed Implementation

[0059] To provide a more detailed description of this disclosure, the following is an illustrative description of various embodiments, but this is not intended to limit the embodiments of this disclosure to their only form. Embodiments of this disclosure may be combined with and / or substituted for each other where advantageous, and other embodiments may be added without further explanation.

[0060] This disclosure aims to provide a fused deposition modeling 3D printer that includes a pressure sensor that can track pressure changes in the extrusion module to accelerate error detection and avoid filament waste or energy consumption.

[0061] Please refer to Figure 1This is a perspective view of a fused deposition modeling 3D printer 10 according to some embodiments of the present disclosure. The X, Y, and Z directions of the reference coordinates are indicated in the figures. The fused deposition modeling 3D printer 10 includes an extrusion module 100. The extrusion module 100 includes an outer frame 102, an extrusion mechanism 104, and a hot end 106. The extrusion mechanism 104 is disposed within the outer frame 102 and includes a first gear 108. The first gear 108 and the hot end 106 are used to extrude and push filament F for fused deposition modeling. The first gear 108 extrudes and pushes the filament F into the hot end 106, where the hot end 106 receives and heats the filament F, making it molten for processing. In some embodiments, the extrusion mechanism 104 further includes a second gear 110. The second gear 110 is configured to mesh with and rotate in opposite directions with the first gear 108 to push the filament F located between them.

[0062] The extrusion mechanism 104 may also include an inner frame 112 and a drive unit 114. A first gear 108 and a second gear 110 are disposed in the inner frame 112. The drive unit 114 is disposed on one side of the inner frame 112, coupled to the first gear 108 and configured to drive the first gear 108 to rotate.

[0063] The fused deposition modeling 3D printer 10 also includes a pressure sensor 116. The pressure sensor 116 is disposed between the outer frame 102 and the extrusion mechanism 104. The pressure sensor 116 is used to sense the pressure value of the extrusion module 100 when extruding and pushing the filament F. In some embodiments, the pressure sensor 116 is a load cell (pressure sensing element). In this way, during the process of the drive unit 114 driving the first gear 108, the pressure sensor 116 can sense the pressure changes experienced by the drive unit 114. By tracking pressure changes, conditions such as blockage of the hot end 106, jamming of the filament F, depletion of the filament F, or malfunction of the drive unit 114 itself can be detected in a timely manner. Therefore, error detection can be accelerated, and continued operation under abnormal conditions can be avoided, preventing filament waste or energy consumption.

[0064] Please refer to Figures 2 to 8B . Figure 2 This is a perspective view of a fused deposition modeling 3D printer 20 according to some embodiments of the present disclosure. Figures 3 to 6 A three-dimensional schematic diagram of some components of a fused deposition modeling 3D printer 20 in its first operating state. Figure 7A A cross-sectional schematic diagram of some components of a fused deposition modeling 3D printer 20 in its first operating state. Figure 7B This is a cross-sectional schematic diagram of some components of a fused deposition modeling 3D printer 20 in a second operating state. Figure 8A and Figure 8B respectively along Figure 7A The line segment A-A' and along Figure 7B The schematic diagram of the cross section shown is illustrated by line segment B-B'.

[0065] like Figure 2 As shown, the fused deposition modeling 3D printer 20 includes an extrusion module 200. The extrusion module 200 includes an outer frame 202, a rotating structure 204, multiple hot ends 206, and an extrusion mechanism 208. The rotating structure 204 and the extrusion mechanism 208 are disposed within the outer frame 202.

[0066] Figure 3 The diagram illustrates the configuration between the rotating structure 204 and the hot end 206. The rotating structure 204 has multiple perforations H. These perforations H are arranged around axis A. Each perforation H is configured to allow a corresponding filament F to pass through. The hot end 206 is positioned below the rotating structure 204. The hot end 206 is positioned corresponding to the perforations H. Specifically, each hot end 206 is aligned with one of the perforations H, so that each hot end 206 receives the filament F passing through the perforation H. In this way, different filaments F can pass through these hot ends 206, and the extrusion module 200 can simultaneously carry multiple colors or materials of filament F, allowing the user to switch between the desired filament F for printing.

[0067] like Figure 2 and Figure 4 As shown, the extrusion mechanism 208 includes an inner frame 210, a first gear 218, a second gear 220, and a drive device 222. The inner frame 210 is disposed in and connected to the outer frame 202. In some embodiments, the extrusion mechanism 208 is rotatably connected to the outer frame 202 via the inner frame 210.

[0068] The inner frame 210 includes a main shaft 212, a first gear housing 214, and a second gear housing 216. The first gear housing 214 and the second gear housing 216 are pivotally connected to the main shaft 212. A first gear 218 and a second gear 220 are respectively disposed in the first gear housing 214 and the second gear housing 216. The first gear 218 and the second gear 220 are configured to mesh with each other and rotate in opposite directions to compress and push the wire F located between them.

[0069] The drive unit 222 is configured to drive the first gear 218 and the second gear 220. For example... Figure 4 As indicated by the arrows, the drive unit 222 is configured to drive the first gear 218 and the second gear 220 to rotate in opposite directions.

[0070] When the extrusion mechanism 208 is in the first operating state, such as Figure 4As shown, the first gear 218 and the second gear 220 mesh with each other, and a hot end 206 is located below the first gear 218 and the second gear 220. The wire F received by this hot end 206 is sandwiched between the first gear 218 and the second gear 220. As the first gear 218 and the second gear 220 rotate, the wire F is squeezed downward and pushed towards the hot end 206, and then the wire F is heated and melted by the hot end 206 to perform melt deposition molding.

[0071] like Figures 5 to 7B As shown, the fused deposition modeling 3D printer 20 also includes a pressure sensor 230. The pressure sensor 230 is disposed between the outer frame 202 and the extrusion mechanism 208. More specifically, the pressure sensor 230 is connected between the outer frame 202 and the inner frame 210. The pressure sensor 230 is used to sense the pressure value of the extrusion module 200 when it extrudes and pushes the filament F. The pressure sensor 230 can sense and track pressure changes on the drive unit 222 and detect abnormalities in a timely manner. For example, the pressure sensor 230 may be, for example, a load cell.

[0072] In some implementations, such as Figure 3 As shown, the rotating structure 204 has multiple grooves R. In the first operating state, a first gear 218 and a second gear 220 are located adjacent to two of the grooves R of the extrusion mechanism 208. Thus, the first gear 218 and the second gear 220 can clamp the corresponding wire F.

[0073] When switching wire F, the first gear 218 and the second gear 220 need to disengage and move out of the groove R to avoid interference between the extrusion mechanism 208 and the rotating structure 204. In some embodiments, the extrusion module 200 also includes an elastic element 224, an elastic element 226 and a cam structure 228, so that the extrusion module 200 can switch wire F in a second operating state.

[0074] Elastic members 224 and 226 respectively connect the first gear receiving portion 214 and the second gear receiving portion 216 to the outer frame 202. More specifically, the first end of the elastic member 224 is connected to a cantilever extending from the first gear receiving portion 214, and the second end of the elastic member 224 relative to the first end is connected to the outer frame 202. The first end of the elastic member 226 is connected to a cantilever extending from the second gear receiving portion 216, and the second end of the elastic member 226 relative to the first end is connected to the outer frame 202.

[0075] like Figure 2 and Figure 5As shown, the cam structure 228 is disposed between the outer frame 202 and the inner frame 210. The rotation axis of the cam structure 228 is connected to the outer frame 202. In some embodiments, the rotation axis of the cam structure 228 is parallel to the X direction. The cam structure 228 is configured to abut against the protrusions of the first gear receiving portion 214 and the second gear receiving portion 216, thereby applying force to the first gear 218 and the second gear 220.

[0076] The following will explain the actuation relationship between the first gear housing 214, the second gear housing 216, the elastic element 224, the elastic element 226 and the cam structure 228.

[0077] First, such as Figure 7A and Figure 8A As shown, in the first operating state, since the cam structure 228 abuts against the inner frame 210 with its higher profile point, the first gear 218 and the second gear 220 can mesh with each other and push the wire F. In the first operating state, although the two elastic elements 224 and 226 are in a stretched state and drive the inner frame 210 to rotate relative to the outer frame 202, the cam structure 228 abuts against the inner frame 210, thus preventing the inner frame 210 from rotating around the main shaft 212.

[0078] Furthermore, such as Figure 7B and Figure 8B As shown, in the second operating state, since the cam structure 228, after being rotated, abuts against the inner frame 210 with its lower profile point, the rotating structure 204 can rotate freely, thereby allowing the switching of different wires F. In the second operating state, since the cam structure 228 abuts against the inner frame 210 with its lower profile point, the two elastic members 224 and 226 can respectively apply force to the first gear receiving part 214 and the second gear receiving part 216, so that the first gear 218 and the second gear 220 are misaligned and disengaged, thereby switching different wires F.

[0079] Please refer to Figures 9 to 14 . Figure 9 This is a perspective view of a fused deposition modeling 3D printer 30 according to some embodiments of the present disclosure. Figure 10 and Figure 11 A three-dimensional schematic diagram of some components of a fused deposition modeling 3D printer 30. Figure 12 , Figure 13 and Figure 14 These are side view, top view, and three-dimensional view of some components of the fused deposition modeling 3D printer 30.

[0080] like Figure 9As shown, the fused deposition modeling 3D printer 30 includes an extrusion module 300. The extrusion module 300 includes an outer frame 302, a rotating structure 304, multiple hot ends 306, and an extrusion mechanism 308. The rotating structure 304 and the extrusion mechanism 308 are disposed within and connected to the outer frame 302. In some embodiments, the fused deposition modeling 3D printer 30 may further include a linear guide rail assembly 350, and the extrusion module 300 can be disposed on the guide rail 352 of the linear guide rail assembly 350 via the outer frame 302.

[0081] like Figure 10 and Figure 11 As shown, some components of the extrusion module 300. For clarity, Figure 10 and Figure 11 A portion of the outer casing of the rotating structure 304 is omitted to show the internal configuration of the wire F within the rotating structure 304 and the idler wheel 320 therein. The rotating structure 304 is generally conical in shape. The rotating structure 304 has a central shaft 310. The rotating structure 304 is rotatably connected to the outer frame 302 via the central shaft 310.

[0082] The rotating structure 304 also has a plurality of through holes H. These through holes H are arranged around the central axis 310 and configured to allow wire F to pass through. After wire F passes through the through holes H, wire F is partially located inside the rotating structure 304.

[0083] The hot end 306 is located below the rotating structure 304. The hot end 306 corresponds to the perforation H. Each hot end 306 is aligned with one of the perforations H, so that the hot end 306 receives the filament F passing through the perforation H. In this way, the extrusion module 300 can simultaneously carry filaments F of multiple colors or materials. By driving the rotating structure 304, the user can select one of the multiple hot ends 306 to switch to the desired filament F for printing, thus improving operating efficiency.

[0084] In some embodiments, the outer frame 302 has a connecting portion 312 that extends from above the top TP of the rotating structure 304 through the side portion SP to below the bottom BP. In other words, the connecting portion 312 can be generally C-shaped. The two ends of the connecting portion 312 are respectively connected to the two ends of the central shaft 310, so that the rotating structure 304 can remain stable during rotation and will not deviate due to load changes.

[0085] like Figure 11As shown, the extrusion mechanism 308 includes a first gear 318, a plurality of idler gears 320, and a drive unit 322. The first gear 318 is disposed on one side of the rotating structure 304. In some embodiments, the first gear 318 is connected to a sun gear in a planetary gear reducer. The idler gears 320 are disposed in the rotating structure 304. The idler gears 320 are arranged corresponding to wires F. For example, two idler gears 320 are disposed next to each wire F. The idler gears 320 and the first gear 318 are configured to rotate in opposite directions to extrude and push the wire F located between the idler gears 320 and the first gear 318, and then the wire F therein is heated and melted by the hot end 306.

[0086] The drive unit 322 is configured to drive the first gear 318 to rotate, which in turn drives the two idler gears 320 to rotate. As the first gear 318 rotates, the wire F is pushed downward toward the hot end 306 and heated and melted by the hot end 306. In some embodiments, the drive unit 322 is, for example, a motor coupled to a planetary gearbox.

[0087] like Figure 12 and Figure 14 As shown, the fused deposition modeling 3D printer 30 also includes a pressure sensor 328. The pressure sensor 328 is disposed between the outer frame 302 and the extrusion mechanism 308. The pressure sensor 328 is used to sense the pressure value of the extrusion module 300 when extruding and pushing the filament F. For example, the pressure sensor 328 can sense and track pressure changes on the drive unit 322 to detect abnormalities in a timely manner. In some embodiments, the pressure sensor 328 is a load cell.

[0088] In some implementations, such as Figure 11 As shown, the extrusion module 300 also includes a worm gear reducer 324. The worm gear reducer 324 is located above the rotating structure 304 and connected to the central shaft 310. The worm gear reducer 324 is configured to rotate or lock the rotating structure 304. The worm gear reducer 324 has a self-locking function, enabling the rotating structure 304 to maintain a stable angle and preventing reverse rotation through worm gear transmission.

[0089] When switching wire F, the first gear 318 needs to disengage from wire F to allow the rotating structure 304 to rotate freely to switch the hot end 306. To achieve this, the extrusion module 300 also includes a rotating structure 326, and the linear guide rail assembly 350 also has a protrusion 354 located at the end of the guide rail 352. When the extrusion module 300 contacts the protrusion 354, the protrusion 354 applies force to the rotating structure 326 of the extrusion module 300, thereby moving the first gear 318 away from the rotating structure 304.

[0090] Furthermore, such as Figure 9 and Figure 13As shown, the rotating structure 326 connects the first gear 318 and the outer frame 302, and the rotating structure 326 has a fixed shaft 326a and a rotating rod 326b. When switching the wire F, the extrusion module 300 moves toward the end of the slide rail 352, causing the rotating rod 326b of the rotating structure 326 to contact the protrusion 354. As the extrusion module 300 continues to move toward the end of the slide rail 352, the protrusion 354 applies force to the rotating rod 326b, causing the rotating rod 326b to rotate around the fixed shaft 326a, thereby moving the first gear 318 away from the rotating structure 304 and separating it from the wire F.

[0091] The detailed description of specific embodiments of this disclosure above clearly shows that in some embodiments of the fused deposition modeling 3D printer of this disclosure, by setting a pressure sensor between the outer frame and the extrusion mechanism, the pressure changes experienced by the extrusion module during the printing process can be detected to determine whether any abnormal conditions have occurred, such as hot-end blockage, filament jamming, filament exhaustion, or malfunction of the drive unit itself. Real-time pressure sensing can accelerate error detection and ensure a more accurate and stable filament extrusion process.

[0092] The foregoing description is only for illustrating and describing exemplary embodiments of this disclosure and is not intended to exhaustively describe or limit the precise forms of the novel features disclosed herein. The above teachings may be modified or varied.

Claims

1. A fused deposition modeling 3D printer, characterized in that, include: An extrusion module includes an outer frame, an extrusion mechanism, and at least one hot end, wherein the extrusion mechanism is disposed in the outer frame and includes a first gear, the first gear and the hot end being used to extrude and push wire for melt deposition modeling; as well as A pressure sensor is disposed between the outer frame and the extrusion mechanism, wherein the pressure sensor is used to sense the pressure value of the extrusion module when it extrudes and pushes the wire.

2. The fused deposition modeling 3D printer as described in claim 1, characterized in that, The extrusion module further includes: A rotating structure, disposed within the outer frame, has a plurality of through-holes, each through-hole being configured to allow wire to pass through, and the through-holes being arranged about an axis. A hot end is located below the rotating structure, and each hot end is aligned with one of the through-holes, thereby receiving the wire. The extrusion mechanism further includes a second gear, wherein the first gear and the second gear are configured to mesh with each other and rotate in opposite directions to push the wire located between the first gear and the second gear.

3. The fused deposition modeling 3D printer as described in claim 2, characterized in that, The extrusion mechanism further includes: The inner frame is disposed within the outer frame and includes a first gear storage portion and a second gear storage portion, wherein the first gear and the second gear are respectively disposed in the first gear storage portion and the second gear storage portion.

4. The fused deposition modeling 3D printer as described in claim 3, characterized in that, The extrusion module also includes two elastic members that connect the first gear receiving portion and the second gear receiving portion to the outer frame, respectively. The two elastic members are configured to apply force to the first gear receiving portion and the second gear receiving portion, respectively.

5. The fused deposition modeling 3D printer as described in claim 3, characterized in that, The extrusion module further includes a cam structure disposed between the outer frame and the inner frame, and the cam structure is configured to apply force to the first gear and the second gear.

6. The fused deposition modeling 3D printer as described in claim 1, characterized in that, The extrusion module further includes: A rotating structure has a central shaft and multiple through holes. The rotating structure is rotatably connected to the outer frame via the central shaft. The through holes are arranged around the central shaft to allow wires to pass through. A hot end is located below the rotating structure, and each hot end is aligned with one of the through holes, thereby receiving the wire. The extrusion mechanism further includes an idler wheel located in the rotating structure, and the first gear located on one side of the rotating structure. The idler wheel and the first gear are configured to rotate in opposite directions to extrude and push the wire between the idler wheel and the first gear.

7. The fused deposition modeling 3D printer as described in claim 6, characterized in that, The outer frame has a connecting portion that extends from the top of the rotating structure to the bottom, and the two ends of the connecting portion are respectively connected to the two ends of the central shaft.

8. The fused deposition modeling 3D printer as described in claim 6, characterized in that, The extrusion module also includes a worm gear reducer located above the rotating structure and connected to the central shaft. The worm gear reducer is configured to rotate or lock the rotating structure.

9. The fused deposition modeling 3D printer as described in claim 6, characterized in that, It also includes a linear guide rail assembly, wherein the extrusion module is disposed on the linear guide rail assembly, and the linear guide rail assembly has a protrusion.

10. The fused deposition modeling 3D printer as described in claim 9, characterized in that, The extrusion module also includes a rotating structure that connects the first gear and the outer frame. When the extrusion module contacts the protrusion, the protrusion applies force to the rotating structure, thereby moving the first gear away from the outer frame.

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