A method of additive manufacture is disclosed. The method may include creating, by a 3D printer contained within an enclosure, a part having a weight greater than or equal to 2,000 kilograms. A gas management system may maintain gaseous oxygen within the enclosure atmospheric level. In some embodiments, a wheeled vehicle may transport the part from inside the enclosure, through an airlock, as the airlock operates to buffer between a gaseous environment within the enclosure and a gaseous environment outside the enclosure, and to a location exterior to both the enclosure and the airlock.

A method of additive manufacture is disclosed. The method may include creating, by a 3D printer contained within an enclosure, a part having a weight greater than or equal to 2,000 kilograms. A gas management system may maintain gaseous oxygen within the enclosure atmospheric level. In some embodiments, a wheeled vehicle may transport the part from inside the enclosure, through an airlock, as the airlock operates to buffer between a gaseous environment within the enclosure and a gaseous environment outside the enclosure, and to a location exterior to both the enclosure and the airlock.

A method of additive manufacture suitable for large and high resolution structures is disclosed. The method may include sequentially advancing each portion of a continuous part in the longitudinal direction from a first zone to a second zone. In the first zone, selected granules of a granular material may be amalgamated. In the second zone, unamalgamated granules of the granular material may be removed. The method may further include advancing a first portion of the continuous part from the second zone to a third zone while (1) a last portion of the continuous part is formed within the first zone and (2) the first portion is maintained in the same position in the lateral and transverse directions that the first portion occupied within the first zone and the second zone.

A method of additive manufacture suitable for large and high resolution structures is disclosed. The method may include sequentially advancing each portion of a continuous part in the longitudinal direction from a first zone to a second zone. In the first zone, selected granules of a granular material may be amalgamated. In the second zone, unamalgamated granules of the granular material may be removed. The method may further include advancing a first portion of the continuous part from the second zone to a third zone while (1) a last portion of the continuous part is formed within the first zone and (2) the first portion is maintained in the same position in the lateral and transverse directions that the first portion occupied within the first zone and the second zone.

An apparatus and a method for powder bed fusion additive manufacturing involve a multiple-chamber design achieving a high efficiency and throughput. The multiple-chamber design features concurrent printing of one or more print jobs inside one or more build chambers, side removals of printed objects from build chambers allowing quick exchanges of powdered materials, and capabilities of elevated process temperature controls of build chambers and post processing heat treatments of printed objects. The multiple-chamber design also includes a height-adjustable optical assembly in combination with a fixed build platform method suitable for large and heavy printed objects.

An apparatus and a method for powder bed fusion additive manufacturing involve a multiple-chamber design achieving a high efficiency and throughput. The multiple-chamber design features concurrent printing of one or more print jobs inside one or more build chambers, side removals of printed objects from build chambers allowing quick exchanges of powdered materials, and capabilities of elevated process temperature controls of build chambers and post processing heat treatments of printed objects. The multiple-chamber design also includes a height-adjustable optical assembly in combination with a fixed build platform method suitable for large and heavy printed objects.

A method of additive manufacture is disclosed. The method may include restricting, by an enclosure, an exchange of gaseous matter between an interior of the enclosure and an exterior of the enclosure. The method may further include running multiple machines within the enclosure. Each of the machines may execute its own process of additive manufacture. While the machines are running, a gas management system may maintain gaseous oxygen within the enclosure at or below a limiting oxygen concentration for the interior.

A method of additive manufacture is disclosed. The method may include restricting, by an enclosure, an exchange of gaseous matter between an interior of the enclosure and an exterior of the enclosure. The method may further include running multiple machines within the enclosure. Each of the machines may execute its own process of additive manufacture. While the machines are running, a gas management system may maintain gaseous oxygen within the enclosure at or below a limiting oxygen concentration for the interior.

The lens apparatus comprises a second lens barrel configured to hold a lens, a first guide bar configured to guide the second lens barrel in an optical axis direction, a bar holding member that holds one end side of the first guide bar, a cam follower engaged with the bar holding member and including a portion eccentric with respect to a rotation axis, and a first fixing member configured to hold the bar holding member via the cam follower. A position on of the one end side of the first guide bar in a plane perpendicular to the optical axis is adjustable by rotating the cam follower with respect to the fixing member from a direction orthogonal to a direction along the optical axis of the lens.

An objective lens unit includes an objective lens, a first rotary member, a second rotary member, and a drive section. The objective lens is provided with a correction ring. The first rotary member is mounted on the objective lens. The second rotary member engages with the first rotary member. The first rotary member has a first engagement portion. The second rotary member has a second engagement portion that is to engage with the first engagement portion. The second engagement portion is disposed at a part in the circumferential direction of the second rotary member. The second rotary member rotates to be positioned at an engagement position or a retraction position. The engagement position is a position where the second engagement portion engages with the first engagement portion. The retraction position is a position where the second engagement portion retracts from the first engagement portion.