Processing head with cutter and associated cleaning system

Abstract

An apparatus for processing a wax mold to smooth it to a predetermined smoothness or mold height and filling the mold with paste. The apparatus has one or more cutting blades and cleaning brushes, the cutting blades rotate over the wax to polish it to the predetermined smoothness or mold height, and the cleaning brushes contact the cutting blades to remove the wax from the cutting blades.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 435,361, filed December 27, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] Technical Field In some of its embodiments, the present invention relates to a processing head with a cutter and associated cleaning system, and more particularly, but not exclusively, to such a cutter for a layerwise additive manufacturing system that forms a layer by 3D printing a mold and then filling the mold with the material that forms this layer. [Background technology]

[0003] In additive manufacturing, layers are built up by printing a mold and then filling it with material. The material can be a metallic or ceramic paste, typically in a viscous liquid form. This process can be used to produce metal and ceramic parts, including mechanical components, which often require very high precision.

[0004] Typically, the shape of the layers is defined by a printed mold, the mold is filled, and then the layers are dried and hardened. The drying process is performed to extract binders and other liquids, which may involve applying a vacuum to the layers. The layers may be heated to harden them, and once all layers are formed, the part is sintered to fuse the metal or other powders provided in the paste to form the part.

[0005] Reference is now made to Figure 1. Figure 1 illustrates the current state of the art, where a processing head 10 for additive manufacturing comprises a die slot 12, rollers 14 and a cutting edge 16.

[0006] Mold 18 is printed using 3D printing technology and a suitable 3D printing material, which is typically wax-based. After printing a new mold layer 18, roller 14, typically a heated cylinder, slightly compresses and flattens the mold surface to more precisely define it.

[0007] The paste is then applied to the space defined in the mold through die slot 12. The paste is applied and spread within the mold by blade 14, for example a doctor blade.

[0008] The blade 14 then removes excess paste from the mold surface. As the blade does so, relative movement occurs between the mold (built part) and the apparatus 10.

[0009] However, the quality of the mold surface produced using rollers is not satisfactory. In the 3D printing process, it is difficult to control the variation in mold thickness caused by, for example, different nozzles or different blocks of the nozzle. Also, it is very difficult to obtain good mold surface quality, and even after considerable calibration, it is still not good or accurate. Summary of the Invention

[0010] In an embodiment of the present application, instead of using a roller to flatten the surface, a cutting head having a blade may be used to polish the surface of the mold. As a result, the cutting blade may polish the mold surface. Because rollers generally do not remove excess mold material, the roller may actually push the material away and even cause distortion of the shape. Therefore, using a cutting blade results in greater precision.

[0011] However, the use of cutting blades presents an additional problem in that the mold material is typically soft and waxy and adheres to the cutting blades, resulting in the blades having to be cleaned periodically.

[0012] To this end, various embodiments provide for cleaning cutting blades such as brushes, and in some embodiments, cooling, which makes the wax harder and less likely to stick, thus making it easier to work with and clean off.

[0013] According to an aspect of some embodiments of the present invention, there is provided an apparatus for processing a waxy mold to smooth the mold to a predetermined smoothness or predetermined mold height and filling the mold with paste, the apparatus comprising: at least one cutting blade configured to rotate over the wax to grind the wax to the predetermined smoothness or predetermined mold height; and a cleaning brush configured to contact the at least one cutting blade to clean and remove wax from the cutting blade.

[0014] In one embodiment, the cutting blade is attached to or contained within a cylinder configured to rotate in a first direction while abrading the wax. In one embodiment, a cutting blade attached to or contained within a cylinder may be used.

[0015] In one embodiment, the cylinder is rotatable to bring each cutting blade into contact with the brush following polishing of the wax.

[0016] In one embodiment, the cylinder is configured to rotate in a second direction when in contact with the cleaning brush.

[0017] In one embodiment, the cleaning brush is configured to move between a standby position and a cleaning position, the cleaning position being in contact with the cylinder and the standby position being spaced from the cylinder.

[0018] In one embodiment, the cleaning brush is a rotating cleaning brush.

[0019] In one embodiment, the cylinder including at least one cutting blade is configured to rotate in a first direction and the rotating cleaning brush is configured to rotate in a direction opposite to the orientation of the first direction.

[0020] In one embodiment, the cleaning brush is configured to rotate to provide a linear velocity that is greater than the linear velocity of the cutting blade.

[0021] In embodiments, a coolant supply may be utilized to provide coolant for cooling the mold or cutting blade. In one embodiment, coolant is provided to cool at least one surface of the cutting blade or mold.

[0022] In one embodiment, the cylinder has an inlet, an outlet, and at least one internal hollow space communicating from the inlet to the outlet for conveying coolant from the inlet to the outlet.

[0023] In one embodiment, the at least one internal hollow space is at a radial distance outward from the central axis of the shaft.

[0024] According to a second aspect of the present invention, printing a mold that defines the shape of a layer of a part; grinding the mold with a cutting blade to define the top surface of the mold to predetermined specifications; Filling the mold with paste; Cleaning the blades; A method of additive manufacturing is provided, including:

[0025] In one embodiment of the method, the cutting blade is attached to a cylinder, and the cylinder rotates in a first direction while abrading the wax.

[0026] The method may include providing a plurality of cutting blades on a cylinder. The blades and cylinder may be integrally constructed or the blades may be attached using a mounting component.

[0027] The method may involve rotating the cylinder to sequentially contact each cutting blade with the brush following abrasion of the wax.

[0028] The method may involve rotating the cylinder in a second direction when the cylinder is in contact with the cleaning brush.

[0029] The method may involve moving the cleaning brush between a standby position and a cleaning position, the cleaning position contacting the cylinder and the standby position spaced from the cylinder.

[0030] In one embodiment of the method, the cleaning brush is a rotating cleaning brush.

[0031] The method may involve rotating the cylinder in a first direction and rotating the rotating cleaning brush in a direction opposite to the orientation of the first direction.

[0032] In one embodiment of the method, the cleaning brush may rotate faster than the cutting blade.

[0033] The method may include providing a coolant to cool the mold or cutting blade.

[0034] The coolant may be supplied externally to cool the surface of at least one cutting blade or die, or alternatively or additionally, the coolant may be conveyed within a cylinder.

[0035] In an embodiment, the coolant is air.

[0036] According to a third aspect of the present invention, printing a mold that defines the shape of a layer of a part; providing a coolant to cool at least one of the die and the surface of the at least one cutting blade; grinding the mold with at least one cutting blade to define a top surface of the mold to predetermined specifications; Filling the mold with paste; A method of additive manufacturing is provided, including:

[0037] According to a fourth aspect of the present invention, there is provided an apparatus for processing a waxy mold to smooth the mold to a predetermined smoothness or a predetermined mold height and filling the mold with paste, the apparatus comprising: at least one cutting blade configured to rotate over the wax to grind the wax to the predetermined smoothness or the predetermined mold height; and a coolant supply source configured to supply coolant to cool at least one member selected from the group consisting of the blade and the mold.

[0038] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. Furthermore, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. [Brief explanation of the drawings]

[0039] Some embodiments of the present invention are herein described, by way of example only, with reference to the accompanying drawings. While specific reference will now be made to the drawings in detail, it is emphasized that the details shown are for the purpose of illustrating and discussing embodiments of the invention by way of example. In this regard, the description taken with the drawings will make apparent to those skilled in the art how embodiments of the invention may be practiced.

[0040] [Figure 1] FIG. 1 is a diagram of a prior art processing head including a roller. [Figure 2A]FIG. 1 shows a cutter with an associated cleaning brush according to a first embodiment of the present invention. [Figure 2B] Variation of the cutter of FIG. 2A as a one-piece construction [Figure 3] 2B is a cross-sectional view of the cutter of FIG. 2A showing the blade of the cutter operating with a cleaning brush in accordance with one embodiment of the present invention; [Figure 4] 2B is a cross-sectional view of a variation of the cutter of FIG. 2A in which a rotating brush is used in accordance with another embodiment of the present invention; [Figure 5] 1 is a cross-sectional view of a die slot and a cutter operating with a blade according to an embodiment of the present invention; [Figure 6] 2B is a diagram of the cutter of FIG. 2A having a hollow interior that may be connected to a coolant source according to another embodiment of the present invention; [Figure 7] 7A is a cross-sectional view of the cutter of FIG. 6 showing the internal passages for the cooling fluid, and FIG. 7B is a cutaway view of the exterior of the cutter of FIG. 6 showing the internal passages for the cooling fluid. [Figure 8] 1 is a simplified flowchart illustrating the operation of one embodiment of the present invention; [Figure 9] 1 is a simplified flowchart illustrating alternative operations according to further embodiments of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0041] In some of its embodiments, the present invention relates to a cutter and associated cleaning system, and more particularly, but not exclusively, to such a cutter for a layer-wise additive manufacturing system that forms a layer by 3D printing a mold and then filling the mold with the material that forms the layer.

[0042] The cutter is for grinding the mold before filling the mold with paste, and the waxy mold may be ground to smooth the mold to a predetermined smoothness or a predetermined mold height before filling the mold with paste. If the mold height is precise enough, the paste may be smoothed to the required accuracy to make a layer that is good enough for the required conditions, and may be suitable for precision mechanical parts, etc., as needed.

[0043] The cutter may include one or more cutting blades, which may be attached to a rotating cylinder. The blades may be separate components attached to the cylinder or may be integrated into the cylinder. The cylinder is associated with a cleaning brush, and the cutting blades rotate over the wax to grind the top surface of the wax to a predetermined smoothness or to a predetermined mold height. The cleaning brush then contacts the cutting blade to clean and remove wax from the cutting blade. Wax left on the blade impairs the blade's ability to grind and smooth the wax to a precise surface.

[0044] The amount of wax removed from the surface of the mold during the polishing process is typically about 20 microns, and at such a thickness, small amounts of wax or residual wax on the cutting blade can cause slight distortion in the polishing process.

[0045] In one embodiment, the cutting blade rotates in one direction while abrading the wax and rotates in a second direction when in contact with the cleaning brush.

[0046] In embodiments, the cleaning brush may move between a standby position and a cleaning position, where the cleaning position is in contact with the cutting blade and the standby position is away from the cutting blade. In this manner, the brush is not in contact with the cutting blade during sharpening. In such embodiments, the cleaning brush may be in the cleaning position when the cutting blade rotates in a second, non-cleaning direction. Thus, if the blade is cutting while moving clockwise, cleaning occurs when the blade is moving counterclockwise, and vice versa.

[0047] In one embodiment, the brush may be cleaned during abrasion.

[0048] In one embodiment, the cleaning brush may rotate faster than the cylinder with the cutting blades, and may rotate in the same or opposite direction.

[0049] In one embodiment, a coolant source may provide a coolant to cool the wax, making it less sticky and more brittle, thus reducing blade fouling and making the wax easier to clean and remove.

[0050] The coolant may be cold air or other fluid.

[0051] The coolant may be supplied to the cutter shaft through an inlet. The shaft may be hollow or may include hollow passages to carry the coolant from the inlet to a separate outlet along part or all of the length of the shaft. This cools the surface that comes into contact with the wax, i.e., the cutting blade, and has the same effect on the wax as described above. In one variant, the coolant may alternatively or additionally be supplied to the mold through a nozzle.

[0052] The internal hollow space may simply be the internal hollow region of the cylinder in which the cutting blade is mounted. There may be a hollow ring at a radial distance outward from the central axis of the shaft.

[0053] Before describing at least one embodiment of the present invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and arrangement of components and / or methods set forth in the following description and / or illustrated in the drawings and / or examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

[0054] Referring now to Figure 2A, a cylinder 20 includes a cutting blade 22 and a hollow central shaft 24, and is associated with a cleaning brush 26. The cleaning brush includes a brush head 28 and bristles 30, which are advantageously tubelets. The tubelets may be, for example, nylon or other plastic.

[0055] As mentioned above, the 3D printing material from which the molds are made is soft and typically waxy, so when the mold material is cut by the various blades 22, the mold material adheres to the blades. Therefore, the cutting edges may require frequent cleaning, or mold quality may be compromised. Mold material that adheres to the blades from a previous operation may leave marks on the mold surface during the next operation.

[0056] Current systems that use blades on wax may be manually cleaned, but manual cleaning requires the machine to be shut down. In additive manufacturing, where leveling is performed for each layer and individual products may be made from hundreds or even thousands of layers, using manual cleaning is impractical.

[0057] In operation, the cylinder 20 rotates and the blades 22 sequentially contact the mold surface, thereby abrading the mold. Following contact with the mold, the blades then contact the bristles 30, which clean and remove residual wax from the mold from the blades 22.

[0058] In an alternative embodiment, the brush 26 is in a standby position during cutting or abrading. After abrading, the brush advances from the standby position to the cleaning position.

[0059] Reference is now made to Figure 2B, which shows an alternative to the cutter of Figure 2A. Cutter 31 is a monolithic construction in which blade 33 is built into shaft 35, i.e., formed integrally with shaft 35. Hollow interior 37 has an insertion portion 39 into the shaft for final positioning.

[0060] Figure 3 is a simplified cross-sectional view of the cylinder and cleaning brush of Figure 2A. The same reference numerals are used and will only be referred to again as necessary for understanding the figure.

[0061] The cylinder 20 is generally circular and has a number of notches around its periphery into which a blade 22, a blade attachment 32, and a bolt 34 are inserted. In one embodiment, the blade attachment may be resilient and may be inserted after the blade to lock itself between the blade and the bolt, holding the blade against the bolt. The blade attachment may then be released, for example, using an appropriately shaped key, to replace the blade.

[0062] Reference is now made to Figure 4, which is a simplified cross-sectional view showing the same cylinder, but with rotating brushes. Parts of the cylinder that are identical to parts in previous figures are given the same reference numerals and will not be described again except as necessary for understanding this figure. Cylinder 20 has blades that extend outward to a radius R1.

[0063] 4, the brush 26 has been replaced with a rotating brush 40. The rotating brush 40 has bristles 42 that extend outward to a radius R2. The radius R2 is selected to allow the bristles to clean the cutting edge of the blade 22. The rotating brush 40 and the cutting cylinder 20 may rotate in opposite directions.

[0064] The outer edge of the blade travels at a linear velocity of R1 x W1. The outer edge of the brush travels at a linear velocity of R2 x W2. References herein to the linear velocity of the blade or brush are intended to refer to the linear velocity of their outer edges.

[0065] In an embodiment, the linear velocity of the brush is set to be greater than the linear velocity of the blade.

[0066] Reference is now made to FIG. 5, a simplified diagram showing a side view of a cutter 50 (shown here without a cleaning brush for simplicity) along with a die slot or paste application section 52. Note that, in contrast to FIG. 1, the die slot does not include a roller, although in embodiments it may hold a roller. Rather, the die slot includes a blade 54, typically known as a doctor blade, for applying the paste. The cutter 50 is positioned above a mold 56 to cut or grind the surface of the mold, after which the die slot fills the space defined by the mold with paste.

[0067] The mold may be printed on top of a previous mold layer or may be printed directly onto the print tray 58.

[0068] Reference is now made to Figure 6, which is a simplified diagram illustrating a variation 60 of cylinder 20, mounted such that a hollow portion within the cylinder is connected to a fluid inlet 62 and a fluid outlet 64. A source of cool air or other fluid (not shown) supplies cool air to fluid inlet 62, and the fluid flows through the hollow portion from inlet 62 to outlet 64, thereby cooling the cylinder. As a result, the blade becomes cooler, which makes the wax in contact with the blade more brittle. Thus, the wax is less likely to smear on the blade and is more easily brushed away by a brush.

[0069] The source of cold air may be, for example, a cold air vortex cooling tool.

[0070] Additionally or alternatively, cold air may be supplied directly to the wax through the die slot or nozzle. That is, the mold surface may be cooled directly, either in conjunction with or independently of internally cooling the cylinder. Direct cooling of the wax may prevent wax from accumulating on the blade, thereby eliminating the need for cleaning.

[0071] Thus, according to an alternative embodiment of the present invention, the cutting blade is not combined with a cleaning brush, but rather with an outlet that directs a coolant at the wax to cool the wax prior to the polishing process. The coolant may be cold air or may be supplied by a cold air vortex device.

[0072] Reference is now made to Figures 7A and 7B, which are a cross-sectional view of cylinder 60 of Figure 6 and a cut-away view of the exterior of cylinder 60, respectively.

[0073] As described, the cylinder 60 is hollow. The internal shaft 70 includes an air inlet 74 and an outlet 76. The shaft 72 is hollow. Air from a cold air source or any other fluid may function as a coolant, as described. The coolant enters through the inlet 74 and travels down the shaft 72 from the inlet 74 to the outlet 76, cooling the cutting head and blade, thereby reducing the stickiness of wax in contact with the cutting edge.

[0074] As shown, the inlets 74 lead to a hollow ring 78 that is radially spaced from the center of the shaft, allowing cool air or other fluid to pass closer to the periphery of the shaft and thereby cool the blades.

[0075] FIG. 7B is a cutaway side view of the exterior of this embodiment of the cutterhead, again showing the shaft 72, air inlet 74, exhaust 76, and hollow ring 78.

[0076] Reference is now made to Figure 8, which is a simplified flowchart illustrating a method of additive manufacturing according to an embodiment of the present invention. Method 90 is performed for each layer of a part or product being manufactured.

[0077] For each layer, a mold is printed (92) to define the shape of the layer's outer boundary. Once printed, the top surface of the mold is imprecise, either because the printing nozzles are not functional or because different print heads with different characteristics are involved in printing different parts of the mold. For this reason, a blade is used (94) to smooth the top of the mold to predetermined specifications. Unlike using a roller, smoothing involves actually polishing the wax surface. Thus, polishing is more precise than using a roller, where the wax is simply pressed and spread. Typically, such a polishing operation removes about 20 microns of wax.

[0078] The smoothed mold is then filled with paste (96). The paste includes the material from which the part will be formed; for example, the material may be a metal or ceramic powder. The doctor blade described above may apply the paste to the cavity of the mold after it exits the die slot.

[0079] The blade is cleaned in step 100. Although shown as a separate step, this is only true in some embodiments. In other embodiments, cleaning is performed simultaneously with cutting. Note that while cleaning is shown after the filling step, in practice it often occurs before or simultaneously with the filling step, and this figure should be interpreted accordingly.

[0080] In other embodiments, the cleaning step is performed separately from the polishing.

[0081] In embodiments, the brush and cutting cylinder may rotate in opposite directions, while in other embodiments, the blade may rotate in one direction while cutting the wax off the mold and in a second direction when in contact with the cleaning brush for the cleaning stage.

[0082] As described in the previous embodiment, the cleaning step may involve moving the cleaning brush between a standby position in contact with the cutting blade and a cleaning position in which the standby position is spaced from the cutting blade.

[0083] The cutting blade may rotate in a direction opposite to that used during cutting during cleaning.

[0084] During cutting, the cleaning brush may be held in a standby position away from the cutting blade as the cutting blade rotates in a first direction to cut the wax.

[0085] Alternatively, the cutting blade may rotate in a first direction to cut wax from the mold, and the cleaning brush may rotate in a second direction to clean, in which case cutting and cleaning may occur simultaneously.

[0086] In embodiments, the cleaning brush rotates at a linear velocity that is faster than the linear velocity of the cutting blade, and such embodiments are applicable to simultaneous cutting and cleaning.

[0087] The coolant may be supplied to the shaft of the processing head through an inlet, the shaft having an internal hollow space that conveys the coolant to an outlet separate from the inlet.

[0088] Reference is now made to Figure 9. Figure 9 shows an alternative embodiment in which a coolant source may provide coolant for externally cooling the die or cutting blade (102).

[0089] The coolant may be air or any other suitable fluid.

[0090] In FIG. 9, step 104 involves printing a mold that defines the contours of the current layer.

[0091] In step 106, a coolant, typically air, is supplied, for example from a vortex device, through the die slots or nozzles to cool either or both the die and cutting blade.

[0092] Step 108 involves grinding the mold using a cutting blade as before to define the top surface of the mold to predetermined specifications. The mold is then filled with paste in step 110.

[0093] Thus, in the embodiment of Figure 9, coolant is introduced externally to the mold and / or blades. This embodiment may be used as an alternative to the embodiment of Figure 8, but a further alternative is to use both in combination.

[0094] In the production of each layer, a drying process is performed to extract binders and other liquids, which may involve applying a vacuum to the layer. The layer may be heated to harden it, or the part may be sintered to fuse the metal or other powders provided in the paste to form the part.

[0095] The terms "comprises," "comprising," "includes," "including," "having," and their cognates mean "including but not limited to."

[0096] The term "consisting of" means "including and limited to."

[0097] The term "consisting essentially of" means that a composition, method, or structure may include additional ingredients, steps, and / or moieties, provided that the additional ingredients, steps, and / or moieties do not materially alter the basic and novel characteristics of the claimed composition, method, or structure.

[0098] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly indicates otherwise.

[0099] It is understood that certain features of the invention that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment, and the description herein shall be construed as if such embodiments were explicitly described herein. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable subcombination, or as suitable modifications to any other described embodiment of the invention, and the description herein shall be construed as if such separate, subcombination, and modified embodiments were explicitly described herein. Certain features described in the context of various embodiments should not be considered essential features of those embodiments, except to the extent that the embodiment cannot function without those elements.

[0100] While the present invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0101] It is the intention of the applicant(s) that all publications, patents, and patent applications mentioned herein be incorporated by reference in their entirety, as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference herein. In addition, citation or identification of any reference in this application should not be construed as an admission that such reference is available as prior art to the present invention. Section headings, if used, should not be construed as necessarily limiting. In addition, any priority document(s) of this application are incorporated by reference herein in their entirety.

Claims

1. 1. An apparatus for treating a wax mold to smooth said mold to a predetermined smoothness or to a predetermined mold height and filling said mold with paste, said apparatus comprising: at least one cutting blade; Cleaning brush and Equipped with the at least one cutting blade is configured to rotate over the wax and grind the wax to the predetermined smoothness or predetermined mold height; the cleaning brush is configured to contact the at least one cutting blade to clean and remove wax from the cutting blade; Device.

2. the cutting blade is attached to or contained within a cylinder configured to rotate in a first direction while abrading the wax; 10. The apparatus of claim 1.

3. a plurality of cutting blades attached to or embedded in the cylinder; 3. The apparatus of claim 2.

4. the cylinder is rotatable to bring each cutting blade into contact with the brush following the abrading of the wax.

4. The device according to claim 2 or 3.

5. the cylinder is configured to rotate in a second direction when in contact with the cleaning brush; 5. The apparatus of claim 4.

6. The cleaning brush is configured to move between a standby position and a cleaning position; The cleaning position is in contact with the cylinder, and the standby position is away from the cylinder. An apparatus according to any one of claims 2 to 5.

7. The cleaning brush is a rotating cleaning brush. An apparatus according to any one of claims 1 to 6.

8. the cylinder with the at least one cutting blade is configured to rotate in the first direction; The rotating cleaning brush is configured to rotate in a direction opposite to the first direction.

8. The apparatus of claim 7.

9. the cleaning brush is configured to rotate to provide a linear velocity greater than the linear velocity of the cutting blade; An apparatus according to any one of claims 1 to 8.

10. a coolant supply source for supplying a coolant for cooling the die or the cutting blade; An apparatus according to any one of claims 1 to 9.

11. the coolant is supplied to cool the surface of the at least one cutting blade or the die; 10. Apparatus according to claim 8 or 9.

12. the cylinder having an inlet, an outlet, and at least one internal hollow space communicating from the inlet to the outlet for conveying the coolant from the inlet to the outlet.

11. The apparatus of claim 10.

13. the at least one internal hollow space being at a radial distance outward from a central axis of the shaft; 13. The apparatus of claim 12.

14. printing a mold that defines the shape of a layer of a part; grinding the mold with a cutting blade to define a top surface of the mold to predetermined specifications; Filling the mold with paste; cleaning the blade; A method of additive manufacturing, comprising:

15. The cutting blade is attached to a cylinder; The cylinder rotates in a first direction while abrading the wax.

15. The method of claim 14.

16. providing a plurality of cutting blades on the cylinder; 16. The method of claim 15.

17. rotating the cylinder to sequentially contact each cutting blade with the brush following the abrasion of the wax.

17. The method of claim 15 or 16.

18. rotating the cylinder in a second direction when the cylinder is in contact with the cleaning brush.

18. The method of claim 17.

19. moving the cleaning brush between a standby position and a cleaning position; The cleaning position is in contact with the cylinder, and the standby position is away from the cylinder. The method according to any one of claims 15 to 18.

20. The cleaning brush is a rotating cleaning brush.

20. The method according to any one of claims 14 to 19.

21. rotating the cylinder in the first direction; rotating the rotary cleaning brush in a direction opposite to the first direction; 21. The method of claim 20, comprising:

22. The cleaning brush is configured to rotate faster than the cutting blade. The method according to any one of claims 14 to 21.

23. providing a coolant to cool the die or the cutting blade; The method according to any one of claims 14 to 22.

24. externally supplying the coolant to cool the at least one cutting blade or the surface of the die.

24. The method of claim 23.

25. conveying the coolant within the cylinder; 24. The method of claim 23.

26. The coolant is air. A method according to any one of claims 23 to 25 or an apparatus according to any one of claims 10 to 12.

27. printing a mold that defines the shape of a layer of a part; providing a coolant to cool at least one of the die and a surface of at least one cutting blade; grinding the mold with the at least one cutting blade to define a top surface of the mold to predetermined specifications; Filling the mold with paste; A method of additive manufacturing, comprising:

28. 1. An apparatus for treating a wax mold to smooth said mold to a predetermined smoothness or to a predetermined mold height and filling said mold with paste, said apparatus comprising: at least one cutting blade configured to rotate above the wax to grind the wax to the predetermined smoothness or predetermined mold height; a coolant supply source configured to supply coolant for cooling at least one member of the group including the blade and the mold; An apparatus comprising:

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