Ripple reduction in an additive manufacturing system
AssigneeStratasys, Inc.
InventorsPaul J. Leavitt, Andrew Rice, Timothy Hjelsand
Life of this patent
Estimating the term…
Abstract
An assembly for use in an additive manufacturing system to print a three-dimensional part that includes an extruder comprising a gear and a motor that turns the gear, wherein rotation of the gear regulates a flow of material out of the extruder. A controller, provides a control signal to the motor to control the rate at which the motor turns the at least one gear and incorporates a time-varying signal into the control signal to reduce ripples in the material output by the extruder.
Claims20
An assembly for use in an additive manufacturing system to print a three-dimensional part, the assembly comprising:
- an extruder comprising:
- a casing assembly having an interior cavity between an inlet and an outlet, wherein the interior cavity is configured to accept a polymeric based material in a molten state;
- a gear retained within the casing, wherein the gear is positioned within the interior cavity and wherein the gear is configured to engage and move the molten polymeric based material towards the outlet;
- and
- a drive that turns the gear, wherein rotation of the gear regulates a flow of material out of the extruder;
- and
- a controller, providing a control signal to the motor to control the rate at which the motor turns the gear, the controller incorporating a time-varying signal into the control signal to reduce ripples in the molten material output by the extruder.
An additive manufacturing system for printing three-dimensional parts, the additive manufacturing system comprising:
- an extruder comprising a gear assembly the gear assembly comprising:
- a casing assembly having an interior cavity between an inlet and an outlet, wherein the interior cavity is configured to accept a polymeric based material in a molten state;
- a pump within the interior cavity of the casing assembly, the pump comprising;
- a first gear;
- and
- a second gear intermeshed with the first gear, the first and second gear counter-rotate and wherein the first and second gears are configured to engage and move the molten polymeric based material towards the outlet;
- and
- a drive configured to drive the first gear;
- and
- a controller assembly operably connected to the drive to provide command signals to the drive, the command signals controlling the rate at which the drive moves the first gear which causes counter-rotation of the second gear, the command signals comprising a time-varying component that reduces variations in a volume of material extruded through the outlet.
A method for printing a three-dimensional part with an additive manufacturing system, the method comprising controlling an extruder comprising counter-rotating first and second gear that moves molten polymeric based material toward an outlet so that the extruder extrudes material onto a surface as part of printing the three-dimensional part, wherein controlling the pump comprises applying a time-varying signal to the extruder to compensate for time-varying changes in the flow of material that would otherwise occur due to mechanical features of the counter-rotating first and second gears.
Dependencies are inferred from the claim text.