Actuator assemblies for additive manufacturing apparatuses and methods for using the same

An actuator assembly for distributing build material and depositing binder material in an additive manufacturing apparatus, the assembly comprising:

• an upper support;
• a lower support spaced from the upper support in a vertical direction, the upper support and the lower support extending in a horizontal direction;
• a recoat head for distributing build material;
• a print head for depositing binder material;
• a recoat head actuator coupled to the recoat head and one of an upper surface of the upper support and a lower surface of the lower support, the recoat head actuator comprising a recoat motion axis, wherein the recoat head actuator is bi-directionally actuatable along the recoat motion axis thereby effecting bi-directional movement of the recoat head;
• a print head actuator coupled to the print head and an other of the upper surface of the upper support and the lower surface of the lower support, the print head actuator comprising a print motion axis, wherein the print head actuator is bi-directionally actuatable along the print motion axis thereby effecting bi-directional movement of the print head, wherein the recoat motion axis and the print motion axis are parallel to one another, extend in the horizontal direction, and spaced apart from one another in the vertical direction;
• a control system comprising a processor and a non-transitory memory storing computer readable and executable instructions that, when executed by the processor, cause the processor to:
• detect position measurements of the print head and the recoat head;
• determine a maximum relative velocity of the print head and the recoat head, the maximum relative velocity equal to a sum of a maximum process velocity of the print head and a maximum process velocity of the recoat head;
• and
• determine a real-time minimum separation distance of a plurality of real-time minimum separation distances between the recoat head and the print head, the real-time minimum separation distance comprising:
• a collision distance component corresponding to the position measurements of the print head and the recoat head;
• and
• a velocity-based component corresponding to the maximum relative velocity;
• and
• a working axis proximity sensor communicatively coupled to the control system, the working axis proximity sensor configured to detect a position of at least one of the recoat head and the print head
• wherein in response to the control system receiving a signal from the working axis proximity sensor indicating that a distance between the recoat head and the print head is less than the real-time minimum separation distance of the plurality of real-time minimum separation distances, the control system sends a signal to halt a manufacturing process,
• wherein the upper support is positioned above a support rail,
• wherein the lower support is positioned below the support rail,
• wherein the support rail extends along an axis extending in the horizontal direction parallel to the recoat motion axis and the print motion axis.