Process for controlling extrusion speed in 3D printing systems
A process for automatically adjusting print speed in a 3D printer, a system for printing a 3D object, and a method of printing a 3D object. A scaling factor is selected, including a first component for print speed and a second component for print quality, an extrusion nozzle port size is identified, and a maximum volumetric extrusion rate for a filament material and a minimum volumetric extrusion rate for the filament material is identified. An optimized volumetric extrusion rate is calculated from the maximum volumetric extrusion rate, the minimum volumetric extrusion rate, and the scaling factor. An optimized X-Y velocity V xy of a print head based on the optimized volumetric extrusion rate is calculated. A computer numerical control code is adjusted to include the optimized X-Y velocity V xy of the print head.
1 . A process of automatically adjusting print speed in a 3D printer, comprising:
selecting a scaling factor, wherein the scaling factor includes a first component for print speed and a second component for print quality;
identifying an extrusion nozzle port size;
identifying a maximum volumetric extrusion rate for a filament material and a minimum volumetric extrusion rate for the filament material;
calculating an optimized volumetric extrusion rate from the maximum volumetric extrusion rate, the minimum volumetric extrusion rate, and the scaling factor;
calculating an optimized X-Y velocity V XY of a print head based on the optimized volumetric extrusion rate; and
adjusting a computer numerical control code to include the optimized X-Y velocity V XY of the print head,
wherein:
the optimized volumetric extrusion rate is calculated from the following:
V
.
E
=
C
1
*
V
.
E
MAX
(
Port
Size
,
Material
)
+
C
2
*
V
.
E
MIN
(
Port
Size
,
Material
)
where
C
1
+
C
2
=
1
,
∀
C
1
≥
0
,
C
2
≥
0
C
1
=
α
C
2
=
1
-
α
0
≤
α
≤
1
wherein {dot over (V)} E is the optimized volumetric extrusion rate, {dot over (V)} E MAX is the maximum volumetric extrusion rate for the filament material through the extrusion nozzle port size, {dot over (V)} E MIN is the minimum volumetric extrusion rate for the filament material through the extrusion nozzle port size, a is the scaling factor for print quality, C 1 is the first component of the scaling factor for print speed and C 2 is the second component of the scaling factor for print quality.
2 . The process of claim 1 , wherein the scaling factor is binary.
3 . The process of claim 1 , where the scaling factor is a sliding scaling factor.
4 . The process of claim 1 , wherein the optimized X-Y velocity V XY of the print head is calculated from the following:
V
XY
=
(
V
.
E
)
Width
TRACE
*
Height
TRACE
=
V
E
*
Eratio
V
.
E
=
V
E
*
Area
Filament
Eratio
=
Area
Filament
Width
TRACE
*
Height
TRACE
.
wherein, V xy is the optimized X-Y velocity in either the X or Y direction, Area Filament is the cross-sectional area of the filament, Width TRACE is the width of the printed, extruded filament, Height TRACE is the height of the printed, extruded filament, E ratio is the relation between the Area Filament and the desired trace cross-sectional area, and V E is the linear velocity of the extruder motor.
5 . The process of claim 4 , wherein if the optimized print head velocity V XY exceeds a maximum machine velocity V XY-MAX , then the optimized print head velocity V XY is set at the machine maximum velocity V XY-MAX .
6 . The process of claim 4 , further comprising selecting a nozzle temperature based on the optimized volumetric extrusion rate {dot over (V)} E .
7 . The process of claim 6 , wherein the computer numerical control code is first generated by a slicer and the process further comprises overriding a slicer temperature command with the nozzle temperature.
8 . The process of claim 1 , wherein the computer numerical control code is first generated by a slicer and the process further comprises overriding a slicer speed command with the optimized X-Y velocity V xy of the print head.
9 . A system for printing a 3D object, comprising:
a print head carried by an x-y carriage, including a nozzle having an extrusion port, wherein the extrusion port exhibits a extrusion nozzle port size; and
a processor control system, wherein the processor control system includes executable code to:
identify the extrusion nozzle port size of the nozzle extrusion port;
identify a maximum volumetric extrusion rate for a filament material and a minimum volumetric extrusion rate for the filament material;
calculate an optimized volumetric extrusion rate from the maximum volumetric extrusion rate, the minimum volumetric extrusion rate, and a scaling factor identified by a user, wherein the scaling factor includes a first component for print speed and a second component for print quality;
calculate an optimized X-Y velocity V XY of the print head based on the optimized volumetric extrusion rate;
adjust a computer numerical control code to include the optimized X-Y velocity V XY of the print head;
calculate the optimized volumetric extrusion rate from the following:
V
.
E
=
C
1
*
V
.
E
MAX
(
Port
Size
,
Material
)
+
C
2
*
V
.
E
MIN
(
Port
Size
,
Material
)
where
C
1
+
C
2
=
1
,
∀
C
1
≥
0
,
C
2
≥
0
C
1
=
α
C
2
=
1
-
α
0
≤
α
≤
1
wherein {dot over (V)} E is the optimized volumetric extrusion rate, {dot over (V)} E MAX is the maximum volumetric extrusion rate for the filament material through the extrusion nozzle port size, {dot over (V)} E MIN is the minimum volumetric extrusion rate for the filament material through the extrusion nozzle port size, a is the scaling factor for print quality, C 1 is the first component of the scaling factor for print speed and C 2 is the second component of the scaling factor for print quality; and
calculate the optimized X-Y velocity V XY of the print head from the following:
V
XY
=
(
V
.
E
)
Width
TRACE
*
Height
TRACE
=
V
E
*
Eratio
V
.
E
=
V
E
*
Area
Filament
Eratio
=
Area
Filament
Width
TRACE
*
Height
TRACE
.
wherein, V xy is the optimized X-Y velocity in either the X or Y direction, Area Filament is the cross-sectional area of the filament, Width TRACE is the width of the printed, extruded filament, Height TRACE is the height of the printed, extruded filament, E ratio is the relation between the Area Filament and the desired trace cross-sectional area, and V E is the linear velocity of the extruder motor.
10 . The system of claim 9 , wherein the processor control system further includes executable code to: set the optimized X-Y velocity V XY as a machine maximum velocity V XY-MAX if the optimized X-Y velocity V XY exceeds the maximum machine velocity V XY-MAX .
11 . The system of claim 10 , wherein the processor control system further includes executable code to: select a nozzle temperature based on the optimized volumetric extrusion rate {dot over (V)} E .
12 . The system of claim 11 , further comprising non-transitory memory operatively coupled to the processor control system, wherein the memory includes information regarding the filament material and a plurality of machine characteristics.
13 . The system of claim 12 , wherein the memory further includes information regarding machine dynamics including the machine maximum velocity V XY-MAX and the maximum machine velocity V XY-MAX .
14 . The system of claim 9 , further comprising a fan configured to cool the nozzle.
15 . The system of claim 9 , further comprising a print platform movable in a z-axis.