Abstract:
A printbed for 3D printers and 3D printed objects has a hole size and thickness that facilitates release of the printed object, that is sufficiently strong to provide a stable base, and that does not cause warping of the printed object either during printing or during release of the object from the printbed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of Provisional Application No. 62/117,439 filed on Feb. 17, 2015, inventors Michael Daniel Armani and David Souza Jones, entitled “3D Printer”. The entire disclosure of this provisional patent application is hereby incorporated by reference thereto, in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       FIELD OF THE INVENTION 
       [0003]    The present invention relates to an improved printbed for 3D printers and 3D printed objects. 
       BACKGROUND OF THE INVENTION 
       [0004]    It is a problem in the art to provide a printbed for 3D printers and 3D printed objects that facilitates release of the printed object, that is sufficiently strong to provide a stable base, and that does not cause warping of the printed object either during printing or during release of the object from the printbed. 
         [0005]    Prior art printbeds for 3D printing have known problems in releasing delicate parts and may cause warping, damage to the printbed itself, and damage to the printed object. 
         [0006]    In the 3D printer industry, the industry standard printbeds have an array of perforations that can fail to release 3D printed support rafts. This is because the holes are relatively tiny, about 1.15 mm. These standard printbeds are well known to use a standard 1.55-1.60 mm thick PCB (fr-4 type phenolic). 
       SUMMARY OF THE INVENTION 
       [0007]    From the foregoing, it is seen that it is a problem in the art to provide a device meeting the above requirements. According to the present invention, a device is provided which meets the aforementioned requirements and needs in the prior art. Specifically, the device according to the present invention provides a printbed for 3D printers and 3D printed objects that facilitates release of the printed object, that is sufficiently strong to provide a stable base, and that does not cause warping of the printed object either during printing or during release of the object from the printbed. 
         [0008]    The present invention employs a novel structure having openings in a specified size ranges, and employing specific materials, such that the printbed facilitates release of the printed object, is sufficiently strong to provide a stable base, and does not cause warping of the printed object either during printing or during release of the object from the printbed. 
         [0009]    Other objects and advantages of the present invention will be more readily apparent from the following detailed description when read in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic front view of a 3D printer and printbed, depicting an object being printed. 
           [0011]      FIG. 2  is a top view of a portion of a printbed surface showing holes therein. 
           [0012]      FIG. 3  is a front view of the printbed of  FIG. 2 . 
           [0013]      FIG. 4  is a greatly enlarged perspective sectional view of the printbed surface of  FIG. 2 , showing the holes therethrough. 
           [0014]      FIG. 5  is a perspective view of a printbed holder supporting by the printbed of  FIGS. 2-5 . A sectional view goes through the printbed, but not the printbed holder. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]      FIG. 1  is a schematic front view of a 3D printer  1  having a printhead  5  in the process of producing a printed object  10 . The object  10  is supported on a printbed  151 . The printbed  151  is supported by a holder  102 . The elements shown in  FIG. 1  are for illustrative purposes only. 
         [0016]    In the present invention, experiments have shown that a perforated hole size with a very fine range of about 1.25 mm-1.6 mm is significantly better in use that the industry standard size. This hole size works well with a standard size PCB having a thickness of 1.55-1.60 mm, and works even better with a double layer having a thickness of 3.2 mm, discussed further below. 
         [0017]    The above-noted hole size is also shown by experiments to be most useful when incorporated in a printbed having a thickness of 3.2 mm. Such a printbed is formed by two 1.55 mm thick PCBs bonded together, as described below. This particular hole structure worked better for a 1.55 mm thick PCB, allowing prints (printed objects) to avoid warping but still allowing release of the rafts. Even more unique to the present invention though, is the use of two PCB&#39;s thermally bonded or glued together to make a 3.2 mm PCB. These PCB&#39;s work better with a 1.4 mm-1.8 mm hole size, trapping plastic even better for the purpose of preventing warp (due to longer holes but stiffer bed), and still allowing release. In an alternative embodiment, a PCB is manufactured to be 3.2 mm in thickness so gluing or thermal bonding is not required. 
         [0018]    The improved performance from an enlargement in hole size, as compared with the prior art, is an unexpected result. Intuitively, it had been thought and expected that a reduction in hole size would provide better results since less material can get into smaller holes. 
         [0019]    Therefore, the greatly improved performance with the print bed of the present invention, by use of large hole sizes, is an unexpected and surprising result. 
         [0020]      FIG. 2  is a top view of a portion of a printbed  151  according to the present invention, having a top member  151   b  and showing a plurality of holes A therein. The printbed  151  is described in further detail hereunder. 
         [0021]      FIG. 3  is a front elevational view of the printbed  151  of  FIG. 2 . In this view, the printbed  151  has the top member  151   b  and a bottom member  151   a.  The printbed  151  and the members  151   b  and  151   a  are described in further detail hereunder. 
         [0022]      FIG. 4  is a greatly enlarged perspective view of a portion of the surface of the printbed  151  of  FIG. 2 , showing the holes A therethrough. It can be seen that the holes A line up on both top member  151   b  and the bottom member  151   a.  In this view, the thickness of the top member  151   b  is indicated by the symbol T 2 , and the thickness of the bottom member  151   a  is indicated by the symbol T 1 . 
         [0023]    Here, T 1  is equal to 1.55-1.60 mm, and T 2  is equal to 1.55-1.60 mm. The material composing the members  151   b  and  151   a  is a standard PCB material. In this view, the diameter of the respective ones of the holes A is indicated by the symbol D. Here, D is in a range of about 1.25 mm-1.6 mm. 
         [0024]      FIG. 5  is a top elevational view of the printbed  151  of  FIGS. 2-5  supported by a printbed holder  102 . While a specific printbed holder  102  is depicted, the present invention is not limited thereto. 
         [0025]    The printbed holder  102  in this instance is a large box housing, which leaves the bottom surface of the bottom member  151   a  exposed to air to allow ventilation. This is significant since the holes A go all the way through both layers  151   b  and  151   a  of the printbed  151 . This ventilation is important because otherwise air prevents the plastic from going into the holes A sufficiently well. 
         [0026]    In the foregoing the dimension range for D (1.25 mm to 1.6 mm) as set forth hereinabove is a critical range. 
         [0027]    The combined thicknesses T 1  and T 2  combine to form a preferred printbed thickness that is substantially equal to 3.2 mm. Other thicknesses can be used, and the preferred thickness is not a critical range. 
         [0028]    The invention being thus described, it will be evident that the same may be varied in many ways by a routineer in the applicable arts. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the claims.