Method And Apparatus Of Very Much Faster 3D Printer

• US 20170291261A1
• Filed: 12/19/2015
• Published: 10/12/2017
• Est. Priority Date: 06/12/2015
• Status: Active Application

• Current Assignee: Ashok Chand Mathur
• Original Assignee: Ashok Chand Mathur
• Inventors: MATHUR, ASHOK CHAND
• Application Number:
  US15/500,444
• Publication Number:
  US 20170291261A1
• Time in Patent Office: Days
• CPC Class Codes: B22F 10/10 Formation of a green body
• CPC Class Codes: B22F 10/20 Direct sintering or melting
• CPC Class Codes: B22F 10/385 Overhang structures
• CPC Class Codes: B22F 10/80 Data acquisition or data processing
• CPC Class Codes: B22F 12/50 Means for feeding of material, e.g. heads
• CPC Class Codes: B23K 1/0056 soldering by means of beams, e.g. lasers, E.B.
• CPC Class Codes: B23K 2103/166 Multilayered materials
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 26/04 Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
• CPC Class Codes: B23K 26/211 with interposition of special material to facilitate connection of the parts
• CPC Class Codes: B23K 26/22 Spot welding
• CPC Class Codes: B23K 26/322 involving coated metal parts using absorbing layers on the workpiece B23K26/18
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/386 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: G06T 19/20 : Editing of 3D images, e.g. changing shapes or colours, aligning objects or positioning parts
• CPC Class Codes: G06T 2219/2004 : Aligning objects, relative positioning of parts
• CPC Class Codes: G06T 7/50 : Depth or shape recovery
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

A 3D printer that is mostly twenty to thirty times faster than existing 3D printers. Pixel-based Raster images are converted into Scalable Vector Graphic (SVG) images, which are then categorized as lines, curves and surface areas. For each category, faster printing methods for printing with pre-formed shapes such as rods, boards, arcs, etc., are disclosed. Pre-formed shapes may be made of plastic/thermoplastic/polymer or sintering materials, as desired. Sintering materials may be cladded/coated with appropriate materials such as solder, copper, and thermoplastics. The new print-head, which has a fixed portion and a replaceable portion, has a mechanism to draw upon pre-formed shapes to print. The replaceable portion has varying shapes and sizes of placement holes, and a mechanism to signal which replaceable portion has been mounted. The print-head incorporates mechanisms to heat and tack the pre-formed shapes. The invention discloses methods to use multiple print-heads to further speed up printing.

Claims

1. A 3D printing process to enhance the speed of printing by known process, the improvement includes performing a pre-printing analysis, comprising the steps of:

a. Converting pixel based raster images into Scalable Vector Graphic (SVG) images;

b. Categorization of SVG images into two, three or more categories;

c. For each category, optimizing printing methods for printing with pre-formed shapes such as rods, boards, arcs, etc., instead of printing with pixels;

d. Computing optimal placements of the pre-formed shapes and storing the placements in the memory of a computer;

e. Communicating the memory of the computer to a print-head configured to handle the pre-formed shapes; and

f. Employing one or more print-heads simultaneously.

2. The 3D printing process of claim 1, where the categories of SVG images include:

a. Relatively thin straight lines 27;

b. Relatively thin curves 28; and

c. Thick occupied surface areas 29.

3. The 3D printing process of claim 1, where the analysis further comprises the steps of:

a. Analyzing a 3D drawing of an object to be printed into multiple plane raster drawings 101;

b. Converting plane raster drawings 101 into the SVG images, where;

i. Original Raster image can be converted into SVG image or;

ii. Original Raster image can be sub-divided into multiple blocks, and different SVG image be made from each such block; and

c. Analyzing the SVG images, which is a two-stage analysis, where;

i. In the first stage, parts of images are categorized into two, three or more categories; and

ii. In the second stage, for each category, a heuristically optimal method is computed to locate the placement points for the pre-formed shapes, including rods 1, 2, 3, boards 7, 8, 9 and arcs 13, 14, 15 to print the image.

4. The 3D printing process of claim 1, where optimizing printing methods for various categories include optimal printing methods for relatively thin straight lines 27, further comprising the steps of:

a. Receiving expected inputs such as the length of the line to be sub-divided for optimal printing;

b. Analyzing the straight lines into component lengths;

c. Computing the number of rods of different lengths that can be fitted by dividing the length of the line by the length of rods to be fit, and dividing the remaining length by the length of shorter rods recursively; and

d. Optionally distributing the lengths so that stability of the object 35 to be printed is ensured using the stability algorithm.

5. The 3D printing process of claim 1, where optimizing printing methods for various categories include optimizing printing methods for the relatively thin curves 28, further comprising the steps of:

a. Calculating the tolerance limit ‘

T’

of the original curve 39;

b. Computing a parallel curve 40 displaced at a distance of the tolerance limit ‘

T’

to the original curve 39;

c. Computing the straight line by joining the two extreme points of the curve 41;

d. Calculating the length of the straight line that joins the two extreme points of the curve 41; and

e. Checking the number of intersections of the straight line with the original curve in different cases, such as the case of zero intersection 50, one intersection 51, and two or more intersections 52, 53, 54, 55, 56.

6. The 3D printing process of claim 1, where optimizing printing methods for various categories include optimizing printing methods for the relatively thin curves 28, further comprising the steps of:

a. Dividing the curve at each point of intersection into two separate curves with two separate chords;

b. Computing tolerance limit ‘

T’

for the new identical but parallel curves, and then sending for conversion into multiple chords;

c. Using a rapid convergence strategy, generating multiple chords such that all these new chords lie between the original curve 61 and the displaced parallel curve 60, 63;

then

d. Dividing the length of the chord ‘

L’

by the length of the rod;

e. Calculating the points on the curve where the lines drawn perpendicular to the chords would intersect the curve 62, using y-axis coordinates;

f. Computing R new chords with generated R+1 pairs of (x, y) coordinates, and the joined adjacent pair of coordinates;

g. Computing the average length of chords with different lengths from the input coordinates of R chords;

h. Dividing the average length by the length of the longest rod. If there is any remaining length then it is again analyzed using the previous steps;

i. Generating new chords such that all the chords lie in between the two parallel curves;

j. Resolving each new chord into rods of different lengths;

k. Optionally imparting stability to the placement of the rods; and

l. Repeating the process until a curve of required thickness is built-up.

7. The 3D printing process of claim 1, where optimizing printing methods for various categories include optimal printing methods for the surface areas 29, further comprising the steps of:

a. Using a long stitch embroidery paradigm 102, where a long diagonal 107 of the surface area is found, and the length of the long diagonal 107 is calculated;

b. Calculating the length of the surface area, ‘

lx’

105, which is the distance between the two extreme points on x-axis and breadth of the surface area, and the length ‘

by’

106, which is the distance between the two extreme points on y-axis; and

then comparing them to find out the long diagonal of the surface area 107;

c. Using an alternate approach to compute the long diagonal by drawing an arbitrary line 120 in the middle of the surface area 119 that aligns itself in the direction of traverse of print-head, and then computing the length ‘

l’

of the long diagonal by traversing it from start to end;

d. Extending the long diagonal in both directions by its length;

at both the new extreme points of the ‘

extended’

diagonal, drawing lines perpendicular to the long diagonal 107;

e. Testing the number of intercepts in different cases using a binary search process;

f. Counting the number of places the long diagonal intersects with the edges of the surface area, and drawing a line that passes through the points of intersection, where;

i. If the line drawn is a tangent, then length ‘

l’

equals to 1, or if the line drawn runs along the straight edge of the curve, ‘

l’

equals to the length of the edge; and

ii. The calculated length ‘

l’

is decomposed into number of rods of different lengths.

8. The 3D printing process of claim 1, where optimizing printing methods for various categories include optimal printing with boards in a manner similar to rods.

9. The 3D printing process of claim 1, where optimizing printing methods for various categories include optimal printing with arcs, further comprising the steps of:

a. Computing the displaced tolerance curve 125 and the chords that lie within the tolerance limit of the curve 128, and then generating multiple new chords;

b. Dividing the length of the new chords created by the length of the arcs;

c. Calculating the number of arcs 129 of different lengths to be fitted, in a way similar to that for optimizing printing methods for curves; and

d. Generating the multiple new chords by computing two parallel curves 132, 133 on either side of the original curve, with the two curves together being within the tolerance limit of the original curve 128 such that all arcs 134 are within the tolerance curves and may straddle the original curve.

10. The 3D printing process of claim 1, where optimizing printing methods for various categories include optimal printing with any combination of rods, boards, arcs and other desired pre-formed shapes.

11. The 3D printing process of claim 1, where a material capable of being sintered is used to pre-form shapes such as rods, boards, arcs, etc. such that:

a. The pre-formed shapes may consist only of sintering material;

b. The pre-formed shapes may be coated with low temperature melting materials such as solder, thermoplastics, or copper; and

c. The print head includes high power laser guns to melt the cladding/sintering material, as required.

12. A print-head for 3D printing, where the print head has a fixed portion 149, a replaceable portion 148, bi-metallic strips 141, and laser guns 135, 139, and is configured to handle pre-formed shapes, such that:

a. The print-head has a fixed portion 149 that receives and holds the replaceable portion 148, where different replaceable portions may have different holes 138 for the pre-formed shapes of different sizes and shapes;

b. The main supply of pre-formed shapes will be outside the print area, from where pneumatic tubes will supply them to the print head;

c. A portion of the print-head holds a limited supply of pre-formed shapes. The replaceable print head has a second set of the pneumatic rounded rectangular tubes that feed a short holding space directly above the pre-formed shape placement holes;

d. The print head uses a bi-metallic strip 141 to prevent pre-formed shapes from prematurely falling down the placement hole 142;

e. The holes 138 have physical separators between them;

the pre-formed shapes that are awaiting their turn 144 to fall are stacked on one or both sides, and the pneumatic mechanism helps to replenish them;

f. The print-head has laser guns 135, 139 mounted at each end of it, and is capable of swill and wiggle motions; and

g. The print-head has an electronic hand-shaking device (chip) 137 built in the replaceable layer 148 to check if the replaceable portion that has been mounted has the desired hole openings.

13. The print-head for 3D printing of claim 12, where the laser guns may be positioned in different ways:

a. The guns 135, 139 placed at the front and back of the fixed portion 149 of the print-head; and

b. The gun 147, which is placed at both the fixed 149, and the replaceable portions 148 of the print head are used as a heat source for fusing.

14. The print-head for 3D printing of claim 12, where motors allow the print head to:

a. Swill by the required angle to place the pre-formed shapes at an angle to the direction of traverse 146; and

b. Wiggle the print-head by a required distance to allow an overhanging placement of newly placed pre-formed shapes over older already placed pre-formed shapes.

15. The 3D printing process of claim 12, where two or more print-heads can be employed simultaneously, where:

a. Printing a center line 162 and right side of the center line 164, with one print-head called the main print-head. The other print-head prints all the left side of the center line 161; and

b. The printing process, which utilizes spiral movements, has two print-heads such that each print-head prints nearly an equal area one half-way radius from the center of the circle and half-way from the outer edge, and the main print-head prints the central spiral and all those inside it.

16. The 3D printing process of claim 12, where the pre-formed shapes deposited on the print bed are held in position by using a Tack and Weld paradigm, comprising:

a. Allowing the separation of the formation of the structure from imparting strength to the formed structure;

b. Holding the pre-formed shapes in the correct position with quick tacks by placing and heating of the new pre-formed shape on the upper surface of the existing pre-formed shapes;

c. Simultaneously, the lower surface of the new pre-formed shape is also heated by the laser guns 135, 139; and

d. Imparting the strength, as desired, within the print area or outside the print area.