Abstract: A powder bed fusion apparatus for building an object, including a processing chamber having a processing chamber aperture, scanner arranged to direct an energy beam to locations in a plane of the aperture and debuilding chamber having a debuilding chamber aperture. The apparatus includes a build chamber including a build sleeve and platform movable therein for supporting powder, the platform including a seal for engaging with the sleeve walls to prevent flow of powder past the platform; and at least one drive mechanism for driving movement of the platform. A translation mechanism moves the chamber between a building position, wherein the sleeve aligns with the processing aperture so an energy beam can be delivered to consolidate powder to build the object, and debuilding position, wherein the sleeve aligns with the debuilding aperture so the object and powder can be inserted into the debuilding chamber through movement of the platform.

Abstract: A method of determining instructions to be executed by a powder bed fusion apparatus, in which an object is built in a layer-by-layer manner by selectively irradiating regions of successively formed powder layers with an energy beam. The method includes determining an exposure parameter for each location within a layer to be irradiated with the energy beam from a primary exposure parameter, the exposure parameters varying with location. An amount each exposure parameter varies from the primary exposure parameter is determined, at least in part, from a geometric quantity of the object derived from the location of the irradiation.

Abstract: Method for measuring an object using a scanning probe carried by a machine tool having a probe holder for the scanning probe and a carrier for the object. The method includes (i) using the machine tool to move the probe holder relative to the carrier along a pre-programmed scan path, (ii) measuring acceleration whilst the pre-programmed scan path is traversed, (iii) collecting probe data whilst the pre-programmed scan path is traversed, and (iv) using the acceleration measured to identify at least one acceleration zone of the pre-programmed scan path and thereby determine one or more positions along the scan path at which the probe data of step (iii) were collected.

Abstract: A coordinate positioning machine includes a plurality of drive axes, each being a rotary or linear drive axis, for positioning a platform within a working volume of the machine, and a separate linear counterbalance axis for counterbalancing the platform. With this arrangement the counterbalance axis can be substantially invariant to changes in orientation of the drive axes and can be counterbalanced by a simple counterweight. Also, an arrangement wherein the counterbalance axes and force generator are arranged so horizontal movement of the platform causes substantially no net movement of and/or no work to be done on the generator. Also, an arrangement wherein a series of counterbalance axes has at least one rotary counterbalance axis, and the generator is arranged behind or at a predetermined distance from the counterbalance axis. Also, an arrangement having a series of counterbalance axes with at most one rotary counterbalance axis between the generator and ground.

Abstract: A powder bed fusion additive manufacturing method in which an object is built in a layer-by-layer manner. The method includes, for each layer of a plurality of successively fused layers, melting material of the layer by irradiating the layer with one or more energy beams a first time using a first set of irradiation parameters and allowing the melted material to solidify to define a fused region of the layer and reheating the fused region by irradiating the layer a subsequent time with one or more of energy beams using a second set of irradiation parameters. The first set of irradiation parameters includes at least one different irradiation parameter to the second set of irradiation parameters.

Abstract: A method of calibrating a coordinate positioning machine is described. The machine is controlled into a pivot pose in which a target point associated with a moveable part of the machine and a pivot point associated with a fixed part of the machine are separated from one another by a known separation. An error value for that pose is determined based on the known separation and a separation expected for that pose from the existing model parameters of the machine. The machine is controlled into a plurality of different target poses, and for each target pose a separation between the target point and the pivot point is measured and an error value for that pose is determined based on the measured separation and a separation expected for that pose from the existing model parameters.

Abstract: A method of laser processing including generating a laser beam having, at different longitudinal positions in a propagation direction, first and second transverse beam profiles of energy density. The first transverse beam profile is different to the second transverse beam profile and is non-Gaussian. The method includes carrying out a scan of the laser beam across a working surface, wherein, during the scan, the laser beam and/or working surface is adjusted such that, for a first part of the scan, the first transverse beam profile is located at the working surface and, for a second part of the scan, the second transverse beam profile is located at the working surface.

Abstract: A method including: a) causing a tool mounted on a machine tool to work on a workpiece, and at least one sensor, which is configured to measure one or more aspects of the tool and/or machine tool, collecting sensor data during said working; b) a measurement device inspecting the part of the workpiece that was worked on at step a) to obtain measurement data; and c) calculating sensor-to-workpiece data calibration information from the sensor data and the measurement data.

Abstract: An additive manufacturing apparatus including a scanner for directing a laser beam on to layers of flowable material to selectively solidify the material to form an object in a layer-by-layer manner. The scanner includes an optical component operable under the control of a first actuator to reflect the laser beam over a first range of angles in a first dimension and the or a further optical component operable under the control of a second actuator to reflect the laser beam over a second range of angles in the first dimension, wherein the second actuator provides a faster dynamic response but a smaller range of movement of the laser beam than the first actuator.

Abstract: A method and apparatus for determining an alignment of an optical scanner for directing an electromagnetic beam to locations within a scan field. The method may include locating a reference element within the scan field of the optical scanner and controlling the optical scanner to cause the electromagnetic beam to be directed to a plurality of different points in the scan field, including at least one point on the reference element. Reflected electromagnetic radiation is detected. The method may include determining when the electromagnetic beam is directed to a reference position in the scan field given by the reference element from a comparison of an intensity of the detected electromagnetic radiation for the different points and determining a corresponding demand signal that causes the optical scanner to direct the electromagnetic beam to the reference position.

Abstract: A coordinate positioning arm includes: a base end and a head end; a drive frame for moving the head end relative to the base end; and a metrology frame for measuring a position and orientation of the head end relative to the base end. The drive frame includes a plurality of drive axes arranged in series between the base end and the head end. The metrology frame includes a plurality of metrology axes arranged in series between the base end and the head end. The metrology frame is adapted and arranged to be substantially separate and/or independent from the drive frame, for example by supporting the metrology frame substantially only at the base end and head end and by providing the metrology frame with sufficient degrees of freedom (via the metrology axes) to avoid creating an additional constraint between the metrology frame and the drive frame.

Abstract: In a workpiece production method a plurality of nominally similar workpieces are produced in a production process on one production machine. The order or time of production of some of the workpieces on the production machine is recorded. Some of the workpieces recorded are measured at two or more inspection stations. Dimensions or points of one workpiece are measured at one of the inspection stations, and corresponding dimensions or points of another of the workpieces are measured at another of the inspection stations. The results of the measurements of corresponding dimensions or points made at the two or more inspection stations are analysed together, taking account of the order or time of production of the workpieces. An output signal is produced based on the analysing of the results together. The output signal indicates performance of the production machine or of one or more of the inspection stations.

Abstract: An improved method is described for measuring a dimension (e.g. diameter) of a non-toothed tool, for example a grinding tool such as a diamond coated burr. The method may be implemented on a machine tool, such as a lathe, machining centre or the like. The method comprises passing a beam of light from a transmitter to a receiver. The receiver produces a received intensity signal related to the intensity of received light. Analysis of variations in the received intensity signal is performed when a rotating tool is moved relative to the light beam to enable a dimension of the tool to be measured. In particular, it may be determined when the received intensity signal has crossed a threshold for at least a defined duration, the defined duration being less than the time taken for one complete rotation of the tool.

Abstract: A method of selecting a scanning sequence of a laser beam in a selective laser solidification process, in which one or more objects are formed layer-by-layer by repeatedly depositing a layer of powder on a powder bed and scanning the laser beam over the deposited powder to selectively solidify at least part of the powder layers, includes determining an order in which areas should be scanned by: projecting a debris fallout zone that would be created when solidifying each area based on a gas flow direction of a gas flow passed over the powder bed; determining whether one or more other areas to be solidified fall within the debris fallout zone; and selecting to solidify the one or more other areas that fall within the debris fallout zone before solidifying the area from which the debris fallout zone has been projected.

Abstract: A method of inspecting at least one feature of a part having a predetermined nominal shape, including: i) loading a contact probe onto a probe mount of a coordinate positioning apparatus which facilitates exchanging of probes thereon and relative movement of the mount and a part in three orthogonal degrees of freedom, the contact probe includes a reference member for engaging the part, and a stylus relative to the reference member and having a tip for contacting the surface to be measured; ii) bringing the reference member and stylus into contact with the part on one side of the feature, and then causing the stylus to traverse collecting measurement data concerning the relative position of tip and the reference member; and iii) extracting feature dimension information from the measurement data, and comparing the extracted dimension information to nominal dimension information for the nominal shape of the feature of the part.

Abstract: A method for determining an attribute of an additive manufacturing apparatus including a plurality of scanners, each scanner including beam steering optics for directing a corresponding radiation beam to a working plane in which material consolidated in layers. The method may include controlling the beam steering optics of a pair of the scanners wherein a first scanner of the pair directs a radiation beam to form a feature in the working plane. The feature is within a field of view of a detector of the second scanner of the pair, the detecting radiation from the working plane is collected by the beam steering optics of the second scanner. Further including recording at least one detector value with the detector of the second scanner for the field of view and determining an attribute of the additive manufacturing apparatus from a comparison of the detector value with an expected detector value.

Abstract: A surface sensing device is mounted on an articulating probe head of a coordinate measuring machine. The device includes an elongate probe holder which is rotatable about an axis. An elongate sensing module includes a surface finish or surface roughness probe with a stylus tip. This is connected to the probe holder via an adjustable knuckle joint. To determine the geometry of the surface sensing device, including the tip normal and drag vector of the stylus tip, the orientations of the probe holder and the sensing module are determined by probing points which are spaced along their lengths, using a separate probe.

Abstract: A powder bed fusion apparatus for building an object in a layer-by-layer manner includes a build platform movable within a build sleeve to define a build volume, a layer formation device for forming layers of powder across the build volume in a working plane and an irradiation device for irradiating powder in the working plane to selectively fuse the powder. The powder bed fusion apparatus further includes a mechanical manipulator arranged to engage with the object and/or a build substrate, to which the object is attached, to tilt the object in a raised position above the working plane such that powder is freed from the object and deposited at a location above the working plane and/or into the build volume.

Abstract: In a workpiece production method a plurality of nominally similar workpieces are produced in a production process on one production machine. The order or time of production of some of the workpieces on the production machine is recorded. Some of the workpieces recorded are measured at two or more inspection stations. Dimensions or points of one workpiece are measured at one of the inspection stations, and corresponding dimensions or points of another of the workpieces are measured at another of the inspection stations. The results of the measurements of corresponding dimensions or points made at the two or more inspection stations are analysed together, taking account of the order or time of production of the workpieces. An output signal is produced based on the analysing of the results together. The output signal indicates performance of the production machine or of one or more of the inspection stations.

Abstract: A sealed linear encoder apparatus provides a measure of relative displacement of two relatively movable members. The sealed linear encoder apparatus includes at least one elongate sealing lip wherein at least a sealing portion of the elongate sealing lip is held in tension along its length.