Fused filament fabrication machine

Patent metadata

Field	Value
Publication number	US-2018169971-A1
Application number	US-201715407024-A
Country	US
Kind code	A1
Filing date	Jan 16, 2017
Priority date	Dec 21, 2016
Publication date	Jun 21, 2018
Grant date	—

Abstract

A fused filament fabrication (FFF) machine includes a cabinet defining a build chamber for building a workpiece including a part and a sacrificial tower for the part at a build location. A head assembly has a filament dispenser for dispensing media through a liquefier tip at the build location during a build process. A controller is operably coupled to the head assembly to control the position of the head assembly and dispensing of the media during the build process. The controller periodically moves the head assembly away from the build location to a tip wipe assembly to clean the liquefier tip during a tip wipe process. The controller moves the head assembly from the tip wipe assembly to dispense a sacrificial slug of material away from the part after the tip wipe process before deposition of the material into the part.

First claim

What is claimed is:

1 . A fused filament fabrication (FFF) machine comprising:
a cabinet defining a build chamber for building a workpiece, including a part and a sacrificial tower for the part, at a build location; a head assembly in the cabinet for dispensing media at the build location during a build process, the head assembly having a filament dispenser for dispensing the media through a liquefier tip of the filament dispenser; a tip wipe assembly in the cabinet remote from the build location; and a controller operably coupled to the head assembly to control the position of the head assembly and dispensing of the media during the build process, the controller periodically moving the head assembly away from the build location to the tip wipe assembly to clean the liquefier tip at the tip wipe assembly during a tip wipe process, the controller moving the head assembly from the tip wipe assembly to dispense a sacrificial slug of material separate from the part after the tip wipe process before deposition of the material into the part.

2 . The FFF machine of claim 1 , wherein the media dispensed immediately after the tip wipe process is not used to build the part.

3 . The FFF machine of claim 1 , wherein the controller moves the head assembly away from the tip wipe assembly to the build location to resume the build process at the sacrificial tower such that the media dispensed immediately after the tip wipe process is used to build the sacrificial tower rather than the part.

4 . The FFF machine of claim 1 , wherein substantially all of the media in the liquefier tip during the tip wipe process is dispensed in the sacrificial tower as the sacrificial slug.

5 . The FFF machine of claim 1 , wherein the controller initiates the tip wipe process at the completion of the layer and the controller resumes the build process at the start of a new layer.

6 . The FFF machine of claim 1 , wherein the filament dispenser includes the liquefier tip and a feed tube routed through a heater, substantially all of the media in the liquefier tip and the feed tube heated by the heater during the tip wipe process is dispensed from the filament dispenser prior to building the part.

7 . The FFF machine of claim 6 , wherein substantially all of the media in the liquefier tip and the feed tube heated by the heater during the tip wipe process is dispensed in the sacrificial tower.

8 . The FFF machine of claim 6 , wherein substantially all of the media in the liquefier tip and the feed tube heated by the heater during the tip wipe process is dispensed in a purge chamber remote from the part and from the sacrificial tower.

9 . The FFF machine of claim 1 , wherein the head assembly builds multiple layers of the part and the sacrificial tower between tip wipe processes.

10 . The FFF machine of claim 1 , wherein the head assembly completes building the corresponding layer of the part prior to initiating the tip wipe process.

11 . The FFF machine of claim 1 , wherein the head assembly includes a positioning system supporting and moving the filament dispenser in the build location, to the tip wipe assembly, and back to the build location.

12 . The FFF machine of claim 1 , wherein the tip wipe assembly includes at least one of a brush and a scraper for removing debris from the liquefier tip.

13 . The FFF machine of claim 1 , wherein the controller includes a build unit storing a program for controlling a build sequence for building the part and the sacrificial tower in layers, the build sequence having predetermined breaks for performing the tip wipe processes, the predetermined breaks occurring during building of the sacrificial tower rather than during building of the part.

14 . A method of operating a fused filament fabrication (FFF) machine having a head assembly with a filament dispenser for dispensing media through a liquefier tip to build a workpiece during a build process, the method comprising:
fabricating a sacrificial tower for the part in layers using the filament dispenser during a sacrificial tower fabricating process; fabricating a part in layers using the filament dispenser during a part fabricating process; and cleaning the liquefier tip at a tip wipe assembly during a tip wipe process, wherein the sacrificial tower fabricating process is performed prior to the part fabricating process after the tip wipe process.

15 . The method of claim 14 , further comprising returning to the workpiece and continuing to fabricate the sacrificial tower after the tip wipe process.

16 . The method of claim 15 , further comprising continuing to fabricate the part after the tip wipe process only after continuing to fabricate the sacrificial tower.

17 . The method of claim 14 , further comprising breaking the build process of the workpiece for the tip wipe process only when not fabricating the part.

18 . The method of claim 14 , further comprising breaking the build process of the workpiece for the tip wipe process only immediately after completion of one of the layers of the workpiece.

19 . A controller for a fused filament fabrication (FFF) machine having a head assembly with a filament dispenser for dispensing media through a liquefier tip, the controller comprising:
a positioning unit for controlling a position of the head assembly; a build unit storing a program for controlling a build sequence for building a workpiece in layers, the workpiece including a part and a sacrificial tower for the part; and a tip wipe unit for initiating a tip wipe process to clean the liquefier tip at a tip wipe assembly; wherein the tip wipe unit periodically causes the positioning unit to move the head assembly to the tip wipe assembly to perform the tip wipe process; and wherein the build unit causes the positioning unit to move the head assembly to the sacrificial tower to reinitiate dispensing of the media at the sacrificial tower after the tip wipe process prior to moving the head assembly to the part such that the media dispensed immediately after the tip wipe process is used to build the sacrificial tower.

20 . The controller of claim 19 , wherein the tip wipe unit moves the head assembly from the workpiece to initiate the tip wipe process only immediately after completion of one of the layers of the workpiece.

21 . The controller of claim 19 , wherein the controller receives at least one input from at least one sensor for controlling at least one of the positioning unit, the build unit and the tip wipe unit.

Assignees

• Boeing Co

Inventors

• Rupel Keith Edward
• Peters Garrett B
• Tackett Derrick E

Classifications

• B29C64/386

  Data acquisition or data processing for additive manufacturing · CPC title

• B29C64/106

  using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material · CPC title

• B29C64/35

  Cleaning · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B29C64/40

  Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof · CPC title