The present application claims the benefits of, and priority from, Chinese Utility Model Patent Application Number CN 201921894307.5, filed Nov. 5, 2019, the entire content of which is incorporated herein by reference.
The present disclosure relates generally to devices for supporting spools, and particularly to devices for supporting filament spools in additive manufacturing systems.
Additive manufacturing is also commonly referred to as three-dimensional (3D) printing. Additive manufacturing technology typically includes various processes to deposit, cure, fuse, or otherwise form layers in sequence to form a 3D object.
The material to be printed in such systems may be fed to the 3D printer as a continuous filament using a filament spool so the filament can be smoothly fed to the 3D printer for printing 3D objects.
For example, the 3D objects may be printed in a layered manner using fused deposition modeling (FDM) techniques. The printing material of an FDM type 3D printer is usually supplied in a solid form of filament and the filament is held on a spool. The diameter of the filament may be 1.75 or 2.85 mm for most FDM type 3D printers currently in use. A typical FDM type 3D printer has a printing head with a feeding gear driven by a motor. During a printing run, the feeding gear pulls the filament from the spool into the printing head. The diameter of feeding gear for many FDM type 3D printers is less than 12 mm. The outside diameter of a typical filament spool current in use is about 200 mm. Existing filament spools for FDM 3D printing can often support up to 5 Kg of the filament material. The filament spools available on the market usually do not include integrated actuation mechanism for motorizing the spools so the spools will only rotate when they are actuated by an external force, such as by being pulled, through the filament on the spool, by the feeding gear of the 3D printer.
As the printer head of a 3D printer typically has a relatively small size, the size of the feeding gear and the pulling force it can generate is also limited. When using a small feeding gear to pull a filament supported on a relatively large spool carrying up to 5 Kg weight, it would be desirable to reduce the rotational resistance on the spool.
A typical filament spool 110 is shown in
Filament spools of different sizes can carry different amounts of filament. Typically, filaments on spools are provided in amounts of 0.5 kg to 5 kg.
As can be appreciated, a filament spool typically has a central passageway for allowing a support axle to pass and may be simply rotatably supported on an axle with a diameter smaller than the diameter of the central passageway of the spool. However, if the axle's size does not fit closely with the size of the passageway, the spool rotation would not be stable and smooth and a larger torque would be required to drive the rotation due to the axial offset between the axis of the axle and the axis of the spool. In such a case, the rotation stability is particularly poor when the filament is made of a flexible material.
An improved conventional technique for supporting filament spools is to provide bearings to support the spool at the spool flanges. For example, as shown in
It is therefore desirable to provide improved devices and technique for supporting filament spools in additive manufacturing systems. For example, it is desirable to provide devices for supporting filament spools of different sizes and providing stable and smooth feeding of the filament.
Accordingly, the present disclosure discloses devices for supporting filament spools of different sizes in additive manufacturing systems and providing relatively stable and smooth feeding of the filament.
An embodiment disclosed herein may be provided as a free-stand, desktop device. For example, a filament holder disclosed herein may be placed beside a 3D printer for supporting a filament spool to feed filaments to the 3D printer. In some embodiments, the device may be attached to or mounted on the 3D printer as a filament holder. In further embodiments, a device as disclosed herein may be mounted onto a vertical wall or panel, or below a ceiling, for supporting the filament spool and feeding filaments to a 3D printer.
In an aspect of the present disclosure, there is provided a device for supporting filament spools in additive manufacturing systems, comprising a rigid axle sized to pass through a central passageway of a filament spool, the axle comprising first and second ends and a cylindrical central section extending between the first and second ends, at least one of the first and second ends configured to be supported on a support structure that supports the axle and the filament spool and restricts rotation of the axle; first and second bushings formed of a rigid material, the first and second bushings sized to rotatably fit over the central section of the axel; and first and second couplers for coupling the first and second bushings, respectively, to the central passageway of the spool, the first and second couplers formed of a resiliently deformable material, wherein each one of the first and second couplers has a tapered outer surface comprising a plurality of teeth for frictionally engaging one of first and second open ends of the central passageway of the filament spool, and has a central bore for receiving and frictionally engaging one of the first and second bushings.
In selected embodiments of the device described in the preceding paragraph, one or more of the following features may be provided. The device may include the support structure, such as being provided in a kit or the same package. The support structure may comprise a base body, and two arms extending from the base body each for supporting one of the first and second ends of the axle. The teeth may be straight bevel gear teeth. Each one of the first and second couplers may have an outer diameter from 10 mm to 400 mm. The resiliently deformable material of the first and second couplers may have a Shore hardness less than 95A. The rigid material of the first and second bushings may have a Shore hardness of more than 75D. The rigid material may be one of nylon, aluminum, steel, and copper. Each one of the first and second bushings may comprise a cylindrical central channel, which may have a diameter of from 6 mm to 200 mm. The axle may be configured to be supported at one of the first and second ends of the axle. The axle may be configured to be supported at both of the first and second ends. The base body may comprise a plurality of through holes for mounting the base body. The each one of the first and second arms may comprise a plurality of slots, each one of the slots configured to receive and support one of the first and second ends of the axle. At least one of the slots may be oriented and configured to support the axle above the base body when the first and second arms are vertically oriented. At least one of the slots may be oriented and configured to support the axle at a side of the base body when the first and second arms are horizontally oriented. At least one of the slots may be oriented and configured to support the axle below the base body when the first and second arms are inversely vertically oriented. The support structure may comprise a rigid material selected from an alloy, steel, aluminum, and a plastic material. The support structure may comprise a generally U-shaped panel having a thickness of from 0.5 mm to 20 mm. The tapered outer surface of each one of the first and second couplers may comprise a plurality of teeth for engaging the open end of the filament spool.
In another aspect of the disclosure, there is provided a support structure for supporting a device described here. The support structure comprises a rigid panel bent into a generally U-shaped profile, comprising a central base body and two arms extending from the base body, a terminal end of each one of the arms comprising a plurality of slots configured to engage and support one of the first and second ends of the axle, wherein the base body comprising a plurality of through holes for mounting the base body; at least one of the slots is configured to support the axle above the base body when the first and second arms are vertically oriented; at least one of the slots is oriented and configured to support the axle below the base body when the first and second arms are inversely vertically oriented; and at least one of the slots is oriented and configured to support the axle at a side of the base body when the first and second arms are horizontally oriented.
Other aspects, features, and embodiments of the present disclosure will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.
In the figures, which illustrate, by way of example only, embodiments of the present disclosure:
In overview, it has been recognized that when a spool holder has tapered couplers (e.g. generally cone-shaped) for coupling a filament spool to the axel of the spool holder, it is convenient to mount spools of different sizes on the same axle. When the couplers are resiliently deformable and have teeth on their outer surfaces and are coupled to the axle of the spool through rigid bushings, stable and smooth rotation of the filament spool can be conveniently achieved.
Further, a spool holder support structure may be provided for mounting the spool holder in various orientations and configurations.
Embodiments disclosed herein may be used for supporting filaments spools used in additive manufacturing systems.
One or more filament feeding problems may arise if the filament is mounted on a conventional spool. Such problems are illustrated using the 3D printing device depicted in
3D printer 100 includes a horizontal build plate 160. The printing material is provided by a filament 106, which is wound around a filament spool 110. The 3D printer 100 has an electro-mechanical printing head 128. The printing head 128 has a pulling gear 124, a roller 122, a heating chamber 130, a heater 140 and a nozzle 150. The parts and constructions of the 3D printer 100 are known to those skilled in the art and will not be described in detail.
Example FDM type 3D printing devices and techniques are described in, for example, U.S. Pat. Nos. 4,749,347 and 5,121,329, the entire contents of which are incorporated here by reference.
The filament, or the print material, may be any material that is suitable for printing a 3D object using additive manufacturing techniques. For example, the print material may have properties and characteristics that are suitable for being continuously fed to an extruder to be softened or melted and then extruded or otherwise emitted from a nozzle or printing head to be deposited on a surface, and can then cure or harden. Different materials may be printed at the same or different types and may be provided in the same or different filaments. Suitable print materials may include the so-called “build material” that forms permanent portions of a 3D-printed object and a “support material” that forms temporary structures to support portions of the already printed build material during a 3D printing process. The support material can be optionally removed after completion of the printing process. Examples of suitable print materials include acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyethylene terephthalate glycol (PETG), polyamide (PA), polyvinyl alcohol (PVA), thermoplastic polyurethane (TPU), and the like. Other materials capable of forming solid objects by extrusion may also be used. The print material may be supplied as a continuous elongated filament of a circular cross-section. The filament may have a diameter ranging from 1.5 to 3.5 mm, or a larger or smaller diameter. The filament is typically provided and available on a filament spool.
During use, the filament 106 is fed to the printing head 128 and then deposited as a thin layer of melt filament 109 onto the build plate 160. Generally, the filament 106 is melted in the heating chamber 130 and extruded out of the nozzle 150. For printing each layer, the nozzle 150 is controlled to move horizontally in the X and Y directions as the melted print material is extruded so as to deposit a desired pattern of the melted print material on the base plate or on top a previously printed layer. The newly printed layer then cools and hardens. Thus, layer by layer, the printed material or layers are stacked in the vertical direction (Z axis) to form a 3D object. By controlling the movement of the nozzle 150 and the rate of extrusion of the print material, the printed 3D object may have any desired shape.
The print material is melted when the temperature of the print material is increased, such as by heating, to above the melting point of the material. The print material does not need to be completely melt and transform into a liquid phase. It is sufficient if filament or print material is softened, or changes its phase, so the material can be extruded or printed through a nozzle or a printing head.
The printing head of a 3D printer may include an extruder. An extruder may have a heater for melting the filament in a chamber of the extruder and may have a nozzle for extruding the melted print material. A nozzle typically has an orifice or opening with a suitable size for extruding the print material in an adequate amount or rate for 3D printing. From the opening of nozzle, the melt filament is emitted as a continuous linear stream. The dimension of the nozzle orifice or opening can affect the width of the printed or extruded material while the nozzle is moving in a horizontal direction.
The pulling gear 124 can be driven by a step motor (not shown) to rotate and pull the filament 106 into the heating chamber 130. This pulling action will cause the filament spool 110 to rotate in the direction as indicated by the arrow 113. The filament 106 can thus be continuously fed to the printing head 128 for printing. After the filament 106 is heated by the heater 140, the filament melts in the heating chamber 130 and is expelled from the nozzle 150 to form a stream of melt material 109, which is deposited on the build plate 160 or on top of a previously deposited layer 108.
As shown in
A typical filament spool 110 for use on 3D printer 100 is further illustrated in
The outer diameters of the flanges or walls 112, 114 of the filament spool 110 may be from 75 mm to 500 mm. The filament material carried on the filament spool 110 may be from about 0.5 kg to about 5 kg.
As can be appreciated by those skilled in the art, filament spools available on the market have various dimensions and shapes and are made of different materials. For example, commercially available filament spools may have an outer diameter (diameter of walls 112, 114) varying from 75 to 500 mm. The length of the central hub 116 between the walls 112, 114 may vary from 45 mm to 600 mm. The outer diameter of the center hub 116 may vary from 20 mm to 100 mm. The diameter of the cylindrical passageway 115 may vary from 15 mm to 95 mm.
The present inventor recognized that when the filament is pulled, such as by the pulling gear 124, the filament spool supported on a conventional spool holder can be subjected to relatively high rotational or frictional resistance, which prevents the spool from rotating freely, the feeding of the filament 106 to the printing head 128 might become unstable, such as being reduced in speed, or suspended, leading to under-feeding of the filament 106. With less filament 106 being fed into the printing head 128, there will be less filament material emitting from the nozzle 150. The inter-layer bonding of a 3D object printed under such a condition will be much weaker and in most cases the printing will fail due to insufficient printing material for forming a continuous layer.
Another problem that may arise is that the pulling gear 124 generates much less pulling force on flexible filaments or filaments with a slightly smaller diameter, as compared with rigid filament materials and larger filament sizes.
It has also been recognized by the present inventor, it is desirable to have a filament spool mounting devise that exhibits reduced or minimum frictional resistance during rotation of the spool. It is also desirable that the spool mounting or supporting device can work with various types of filaments, including regular rigid filaments, flexible filaments and filaments with a small diameter such as a diameter of 1.5 mm to 2 mm.
To address one or more of these and other issues discussed herein, a device for rotatably supporting the filament spool 110 is provided, according to an example embodiment of the present disclose. The device includes a rigid axle sized to pass through a central passageway of a filament spool. The axle has first and second ends and a cylindrical central section extending between the first and second ends. At least one of the first and second ends is configured to be supported on a support structure that supports the axle and the filament spool and restricts rotation of the axle. Two bushings formed of a rigid material are also provided, which are sized to rotatably fit over the central section of the axle. Two couplers are provided for coupling the bushings respectively to the central passageway of the spool. The couplers are formed of a resiliently deformable material and have a tapered outer surface and teeth for frictionally engaging the open ends of the central passageway of the filament spool. Each coupler also has a central bore for receiving and frictionally engaging one of the bushings.
An example embodiment of such a device is illustrated in
As illustrated in
The couplers 501 are made of a resiliently deformable material. The resiliently deformable material may be a rubber material or have rubber-like properties. The material may have a hardness less than Shore 95A. The flexible coupler 501 is sized and configured to tightly fit into the open ends of the central passageway 115 of the filament spool 110. When assembled, couplers 501 will rotate with the filament spool 110 and there is ideally no relative movement between the couplers 501 and the hub 116 of the filament spool. Thus, as better illustrated in
Coupler 501 includes hollow sections 355 between the outer rim 357 and the inner rim 358 and a number of reinforcing ribs 359 extending from the inner rim 358 to the outer rim 357. Ribs 359 may be evenly distributed around the circumference of the rims 357 and 358. Inner rim 358 may also be recessed inwardly with respect to outer rim 357, as illustrated in
The bushing 508 is further illustrated in isolation in
During assembly, each bushing 508 may be pushed into the bore 353 of a corresponding coupler 501 to form a tight-fit and engagement. Each pair of engaged bushing 508 and coupler 501 will rotate together during operation. The inner cylindrical surface 509 of busing 508 may have a diameter larger than the diameter of the cylindrical central section of the axle 502, such as by about 0.2 mm to about 10 mm. As a result, the axle 502 can be easily slid into the central bore 509 of bushing 508 to form a loose fit and the bushing 508 can rotate around the axle 502 when the axle is fixed in position and does not rotate.
Axle 502 may be made of a rigid material such as nylon, aluminum, steel, or the like. The rigid axle 502 is fixedly mounted on the support structure and prevented from rotation around its longitudinal axis. The length of the axle 502 may vary from 50 mm to 750 mm. The diameter of the cylindrical central section 503 of the axle may be from 10 mm to 100 mm. The dimensions of the axle may also be varied or selected depending on the spools to be supported and the bushings 508 used.
Axle 502 has two ends 504 and 505, which may have two or more flat faces. The flat faces at the ends 502, 504 can be used to prevent rotation of the axle 502 when the ends 502, 504 are received in the slots of the support arms 520, 521.
In a particular embodiment, the axle 502 can be supported at both ends 504 and 505 by a generally U-shaped support structure 550 as illustrated in
As better seen in
The support arms 520, 521 extend from the ends of the base plate 530 and are generally parallel to each other. Support arms 520, 521 as depicted are elongated panels with a generally rectangular cross-section. However, in different embodiments, they may have different shapes.
In some embodiments, each support arm 520, 521 has three slots, 522, 524, 526 and 523, 525 and 527 respectively, at the terminal end of the art, which form a “hand” for holding an end 504, 505 of the axle 502. The slots may be formed as cutouts.
Slot 522, 523 is on the top, or far end, of the arm 520, 521 and faces away from base plate 530. Slot 524, 525 is facing outwardly from a side of the arm 520, 521. Slot 527, 526 faces towards the base plate 530.
Device 500 may be configured in different manners to mount and support the filament spool 110 for feeding filament to 3D printer 100.
For example, the slots 522 and 523 may be identical in shape and size and may be sized and positioned to receive the ends 504, 505 of the axle 502 respectively. Thus, the filament spool 110 can be held above the support structure 550 as the support structure 550 is in an upright orientation, as shown in
The upright arrangement of the spool 110 and device 500 as shown in
The slots 524 and 525 may be identical in shape and size and may be sized and positioned to receive ends 504, 505 of the axle 502 respectively. The filament spool 110 may be supported using slots 524, 525 with the support structure 550 oriented horizontally as illustrated in
In some embodiments, slots 526 and 527 may be identical in shape and size and may be sized and positioned to receive the ends 504, 505 of the axle 502. As illustrated in
In an alternative embodiment, device 500 in the upright configuration may be mounted and supported any horizontal surface or support, and may be used as a free-stand filament holder in proximity of the 3D printer 100, without being physically affixed to the 3D printer 100, or to a wall or a ceiling.
In some embodiments, device 500 in the upright configuration may be mounted on a stand, or rails or tracks. For example, as illustrated in
The filament spool 110 may be supported on device 600 as illustrated in
In an embodiment, device 600 may be mounted on a side of a printer housing, such as the housing of 3D printer 100, as illustrated in
In alternative embodiments, couplers 501 and 601 may be replaced with a coupler 701 as illustrated in
In the embodiment illustrated in
In an alternative embodiment, the sleeve 704 may have a conical outer surface and the teeth 775 may be tapered or have uniform heights from end 782 to end 784. The overall profile of the coupler 701 in such a configuration is still conical or generally cone shaped.
For clarification, it is noted that in this disclosure, when directional orientations such as “above”, “below”, “top”, “bottom”, and the like are made with reference to a 3D printer, it is assumed that the 3D printer is oriented in the normal operation (printing) position.
R should also be understood that modifications and variations to the specific embodiments described above are possible.
It will be understood that any range of values herein is intended to specifically include any intermediate value or sub-range within the given range, and all such intermediate values and sub-ranges are individually and specifically disclosed.
It will also be understood that the word “a” or “an” is intended to mean “one or more” or “at least one”, and any singular form is intended to include plurals herein.
It will be further understood that the term “comprise”, including any variation thereof, is intended to be open-ended and means “include, but not limited to,” unless otherwise specifically indicated to the contrary.
When a list of items is given herein with an “or” before the last item, any one of the listed items or any suitable combination of two or more of the listed items may be selected and used.
Of course, the above described embodiments of the present disclosure are intended to be illustrative only and in no way limiting. The described embodiments are susceptible to many modifications of form, arrangement of parts, details and order of operation. The invention, rather, is intended to encompass all such modification within its scope, as defined by the claims.
Number | Date | Country | Kind |
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201921894307.5 | Nov 2019 | CN | national |