Systems and methods of reducing curl and wrap in additive manufacturing
Methods, systems, and apparatus, including medium-encoded computer program products, for reducing or eliminating curl and wrap in additive manufacturing include, in at least one aspect, obtaining a three dimensional (3D) model of a 3D object to be additively manufactured using a thermoplastic material delivery apparatus; generating a variable width brim for at least a first layer of the 3D model, wherein a width of the brim varies from a maximum value to a minimum value at different locations adjacent at least the first layer of the 3D model, and the generating comprises varying the width of the brim in accordance with an amount of convexity of the 3D model in regions corresponding to the different locations; and outputting the variable width brim for use in preventing warping during the additive manufacturing of the object from the 3D model using the thermoplastic material delivery apparatus.
1. A method comprising:
obtaining a three dimensional (3D) model of an object to be additively manufactured using a thermoplastic material delivery apparatus;
generating a variable width brim for at least a first layer of the 3D model, wherein a width of the brim varies from a maximum value to a minimum value at different locations adjacent at least the first layer of the 3D model, and the generating comprises
discretizing a perimeter of the first layer of the 3D model to identify discrete points along the perimeter of the first layer of the 3D model,
determining a convexity for a region of the 3D model by calculating at least one angle between at least two lines formed between at least three of the discrete points associated with the region, and
varying the width of the brim in accordance with an amount of convexity of the 3D model in regions corresponding to the different locations; and
outputting the variable width brim for use in preventing warping during the additive manufacturing of the object from the 3D model using the thermoplastic material delivery apparatus.
2. The method of claim 1 , wherein the minimum value is zero, and the maximum value is a user input value.
3. The method of claim 1 , comprising setting the maximum value in accordance with properties of a thermoplastic material to be used by the thermoplastic material delivery apparatus to additively manufacture the object from the 3D model.
4. The method of claim 1 , wherein generating the variable width brim comprises identifying how many of the discrete points are associated with the region based on a window of convexity being measured, and determining the convexity for the region comprises calculating a weighted average of angles between at least three lines formed between at least four of the discrete points associated with the region.
5. A method comprising:
obtaining a three dimensional (3D) model of an object to be additively manufactured using a thermoplastic material delivery apparatus;
generating a variable width brim for at least a first layer of the 3D model, wherein a width of the brim varies from a maximum value to a minimum value at different locations adjacent at least the first layer of the 3D model, and the generating comprises varying the width of the brim in accordance with an amount of convexity of the 3D model in regions corresponding to the different locations, wherein varying the width of the brim comprises setting the width based on a weighted average of convexity determined for respective layers, including the first layer, of the 3D model; and
outputting the variable width brim for use in preventing warping during the additive manufacturing of the object from the 3D model using the thermoplastic material delivery apparatus.
6. The method of claim 5 , wherein the first layer is assigned a weight of one, and each succeeding higher layer of the respective layers of the 3D model is assigned a weight that is less than the weight assigned to the preceding lower layer.
7. The method of claim 1 , wherein generating the variable width brim comprises creating a perforated edge in the brim where the brim contacts the 3D model.
8. The method of claim 7 , wherein creating the perforated edge in the brim comprises distributing evenly spaced holes along a perimeter of the first layer of the 3D model.
9. The method of claim 1 , comprising using a 3D modelling program to perform the generating and the varying at a mesh level of the 3D model, and wherein the outputting comprises saving the 3D model with the variable width brim added thereto.
10. The method of claim 1 , comprising using a slicer program to perform the generating and the varying during conversion of the 3D model to a toolpath domain of the thermoplastic material delivery apparatus, and wherein the outputting comprises sending a toolpath specification document to the thermoplastic material delivery apparatus for additive manufacturing, wherein the toolpath specification document includes slices of the 3D model and the variable width brim.
11. A non-transitory computer-readable medium encoding instructions operable to cause data processing apparatus to perform operations comprising:
obtaining a three dimensional (3D) model of an object to be additively manufactured using a thermoplastic material delivery apparatus;
generating a variable width brim for at least a first layer of the 3D model, wherein a width of the brim varies from a maximum value to a minimum value at different locations adjacent at least the first layer of the 3D model, and the generating comprises
discretizing a perimeter of the first layer of the 3D model to identify discrete points along the perimeter of the first layer of the 3D model,
determining a convexity for a region of the 3D model by calculating at least one angle between at least two lines formed between at least three of the discrete points associated with the region, and
varying the width of the brim in accordance with an amount of convexity of the 3D model in regions corresponding to the different locations; and
outputting the variable width brim for use in preventing warping during the additive manufacturing of the object from the 3D model using the thermoplastic material delivery apparatus.
12. The non-transitory computer-readable medium of claim 11 , wherein the minimum value is zero, and the maximum value is a user input value.
13. The non-transitory computer-readable medium of claim 11 , the operations comprising setting the maximum value in accordance with properties of a thermoplastic material to be used by the thermoplastic material delivery apparatus to additively manufacture the object from the 3D model.
14. The non-transitory computer-readable medium of claim 11 , wherein generating the variable width brim comprises identifying how many of the discrete points are associated with the region based on a window of convexity being measured, and determining the convexity for the region comprises calculating a weighted average of angles between at least three lines formed between at least four of the discrete points associated with the region.
15. A non-transitory computer-readable medium encoding instructions operable to cause data processing apparatus to perform operations comprising:
obtaining a three dimensional (3D) model of an object to be additively manufactured using a thermoplastic material delivery apparatus;
generating a variable width brim for at least a first layer of the 3D model, wherein a width of the brim varies from a maximum value to a minimum value at different locations adjacent at least the first layer of the 3D model, and the generating comprises varying the width of the brim in accordance with an amount of convexity of the 3D model in regions corresponding to the different locations, wherein varying the width of the brim comprises setting the width based on a weighted average of convexity determined for respective layers, including the first layer, of the 3D model; and
outputting the variable width brim for use in preventing warping during the additive manufacturing of the object from the 3D model using the thermoplastic material delivery apparatus.
16. The non-transitory computer-readable medium of claim 15 , wherein the first layer is assigned a weight of one, and each succeeding higher layer of the respective layers of the 3D model is assigned a weight that is less than the weight assigned to the preceding lower layer.
17. The non-transitory computer-readable medium of claim 15 , wherein generating the variable width brim comprises creating a perforated edge in the brim where the brim contacts the 3D model.
18. The non-transitory computer-readable medium of claim 17 , wherein creating the perforated edge in the brim comprises distributing evenly spaced holes along a perimeter of the first layer of the 3D model.
19. The non-transitory computer-readable medium of claim 15 , the operations comprising using a 3D modelling program to perform the generating and the varying at a mesh level of the 3D model, and wherein the outputting comprises saving the 3D model with the variable width brim added thereto.
20. The non-transitory computer-readable medium of claim 15 , the operations comprising using a slicer program to perform the generating and the varying during conversion of the 3D model to a toolpath domain of the thermoplastic material delivery apparatus, and wherein the outputting comprises sending a toolpath specification document to the thermoplastic material delivery apparatus for additive manufacturing, wherein the toolpath specification document includes slices of the 3D model and the variable width brim.