A 3D printing apparatus and method corrects for skew in the motion components of the apparatus without the use of an independent reference object. A calibration object having features therein or thereon is printed. A user rotates the calibration object by a certain angle after it is printed. The features in/on the calibration object are measured, and an amount of skew is determined based on the measurements. In addition, a 3D printing operation is compensated based on the effects of a coefficient of thermal expansion and/or moisture absorption on dimensional changes.

This method, which allows acquisition and computation of geometrical data of at least one pattern associated with an ophthalmic object (6) for manufacturing ophthalmic lenses similar to the object or complementary thereto, is of the type in which a device (12) for acquiring and computing geometrical data is used, which comprises: a transparent support (13) adapted for bearing an ophthalmic object; on one side of the support, means (17) for illuminating this support; on the other side of the support, a video camera (25) adapted for producing a video signal representative of at least one pattern associated with the ophthalmic object laid on the support; and signal processing and analysis means (27) receiving at the input the video signal produced by the camera, and adapted for computing and providing the geometrical data. The method is characterized in that: (a) a verification pattern independent of said geometrical data is traced on the ophthalmic object (6), this verification pattern being asymmetrical relatively to each of two axes perpendicular to each other; (b) the ophthalmic object is positioned on the transparent support (13) of the acquisition and display device (12); and (c) by means of said device (12), said verification pattern is optically captured and analyzed.

Techniques are described for calibrating an optical system in an additive fabrication device using an image of the build surface within the device. These techniques allow calibration to be performed by imaging one or more calibration features generated on (or at) the build surface, which may include illuminated regions of the build surface, regions of the build surface on which solid material has been formed, and/or regions of the build surface to which energy has otherwise been directed thereby making those regions distinguishable from their surroundings. The calibration features may be produced (at least in part) by the optical system to be calibrated. The location of the calibration features within the image may be compared with the intended location of these calibration features, and corrections to the optical system determined based on any differences between the actual and intended locations.

A kit for the calibration of a head system of a power radiation source of an additive manufacturing device comprises: a calibration plate having a plurality of reference marks, and a firing support made from at least one material sensitive to the radiation of the source, this support leaving the reference marks of the calibration plate visible when it is in place thereon, characterized in that the firing support comprises a plurality of windows distributed in such a way as to become superposed with the various reference marks of the calibration plate and leave them visible when the firing support is in place on the calibration plate. There is also a method for calibrating such a system.

A kit for the calibration of a head system of a power radiation source of an additive manufacturing device comprises: a calibration plate having a plurality of reference marks, and a firing support made from at least one material sensitive to the radiation of the source, this support leaving the reference marks of the calibration plate visible when it is in place thereon, characterized in that the firing support comprises a plurality of windows distributed in such a way as to become superposed with the various reference marks of the calibration plate and leave them visible when the firing support is in place on the calibration plate. There is also a method for calibrating such a system.

The invention relates to a device (10) for the layered production of a three-dimensional workpiece, comprising: a build space (30) in which the workpiece is manufacturable by selectively solidification of raw material powder layers; an irradiating system (20) which is adapted to selectively solidify the raw material powder layers in the build space (30) by emitting a processing beam; at least one calibrating structure (36); a sensor arrangement (25) which is adapted to detect an irradiation of the calibrating structure (36) by the irradiating system (20); and a control unit (26) which is adapted to calibrate the irradiating system (20) on the basis of detection information of the sensor arrangement, wherein the calibrating structure (36) is arranged outside the build space (30). The invention also relates to a method for calibrating an irradiating system of a device for the layer-by-layer manufacture of a three-dimensional workpiece.

Techniques are described for calibrating an optical system in an additive fabrication device using an image of the build surface within the device. These techniques allow calibration to be performed by imaging one or more calibration features generated on (or at) the build surface, which may include illuminated regions of the build surface, regions of the build surface on which solid material has been formed, and/or regions of the build surface to which energy has otherwise been directed thereby making those regions distinguishable from their surroundings. The calibration features may be produced (at least in part) by the optical system to be calibrated. The location of the calibration features within the image may be compared with the intended location of these calibration features, and corrections to the optical system determined based on any differences between the actual and intended locations.

A system and method of controlling the input and output speed of a continuous sheet of stock material is provided. More specifically, the present invention relates to a system and method used to perform an operation on a continuous sheet of stock material in a high speed manufacturing system. The continuous sheet of stock material may subsequently be received by a second system that performs a different operation on the stock material. In one embodiment, the second system forms the stock material into tabs for container end closures. The system includes an infeed accumulation device and an outfeed accumulation device. The infeed and outfeed accumulation devices enable the system to operate at a variable rate and out of phase with a high speed, coil fed manufacturing system to which the system may be removably integrated.

Techniques are described for calibrating an optical system in an additive fabrication device using an image of the build surface within the device. These techniques allow calibration to be performed by imaging one or more calibration features generated on (or at) the build surface, which may include illuminated regions of the build surface, regions of the build surface on which solid material has been formed, and/or regions of the build surface to which energy has otherwise been directed thereby making those regions distinguishable from their surroundings. The calibration features may be produced (at least in part) by the optical system to be calibrated. The location of the calibration features within the image may be compared with the intended location of these calibration features, and corrections to the optical system determined based on any differences between the actual and intended locations.

A calibration subsystem comprising: a control system that provides a control signal to a fabrication machine to process a sample of a workpiece, at least one sensor sensing the effect that the processing had on the sample, wherein the control system computes the difference between the sensed effect and a desired effect, and the control system, in accordance with the difference, updates settings of the subtractive fabrication machine and/or of one or more models to be cut subsequently.