PLMXML FD (FeatureDescriptions) Schema Note: all length values are in metres, all angles are in radians. Thread Entry Setting. Thread Extent. finite: of specific length toExtent: extent is that of the parent feature This element describes a Thread. Note: the thread defaults to right-handed. An attribute to indicate left-handed may be added in the future if required. Attributes: type: The type (standard) of thread. Some possible values are: ANSI threads: UNC, UNF, UNEF ANSI pipe threads: NPSM, NPT ISO threads: M ISO pipe threads: Rp, Rc This attribute is a string to allow custom standards. extent: The extent type of the thread. length: The length of the thread, if extent = 'finite'. offset: The offset distance, from the start of the owning feature, before the thread starts. nominalDiameter: Nominal diameter, i.e. diameter of cylinder to which the thread applies. internalDiameter: Diameter as applied to inside of thread. externalDiameter: Diameter as applies to outside of thread. For these three diameters we have: internalDiameter .LT. nominalDiameter .LT. externalDiameter designateDiameter: Designated diameter. This is a string, e.g. "M8". effectiveLength: This is the length of the thread which is cut at full depth. height: The distance from the inside of the thread to the outside of the thread. TODO: check if we need this as well is internal and externalDiameter? taperAngle: The angle of taper, in radians. This is positive and less than pi/2. The taper is always towards the centreline, in the direction of the thread. pitch: The distance between adjacent threads, measured along the length of the thread, in metres (SI units). This element specifies a CounterSink component of a HoleFeature. The CounterSink starts with a given diameter and tapers down. Attributes: diameter: The diameter of the start of countersink. angle: The angle of the countersink. This is the angle between a line lying in the cone of the CounterSink, and a plane through the start of the CounterSink. The range is 0 to pi/2. For example, just below pi/2 would be a nearly-cylindrical CounterSink. length: The length of the countersink along its axis. Elements: EntityRef: Reference to entities that are related to the CounterSink This element specifies a CounterBore component of a HoleFeature. Attributes: diameter: The diameter of the CounterBore. length: The length of the CounterBore. Elements: EntityRef: Reference to entities that are related to the CounterBore Thread: Definition of thread for CounterBore (at most one) Extent of hole, i.e. how its length is determined. throughAll: through all faces throughNext: through to the next face in the model fromTo: between specified points finite: from a specified point for a specified length A component of a HoleFeature. Attributes: diameter: The diameter of the hole. length: The length of the hole. extent: The way the hole length was determined. blindHoleAngle: The angle of the termination of the a blind hole. This is the total angle at the tip, in radians, so pi would be a flat tip. If omitted, the termination is flat. taperAngle: The angle of taper, in radians. This is positive and less than pi/2. Elements: Thread: Definition of Thread(s) for hole component This specifies the position, and optionally the direction, of a Hole. Attributes: position: Position of the start of the hole in global 3-space coords. direction: Direction of of the hole. This direction defines the reference direction when evaluating the sequence of HoleComponent, CounterSink and CounterBore elements; and the extent/offsets values within those items. If absent, the direction attribute on the HoleFeature is used. The way in which the orientation of a hole is determined. normalToEntrySurface: normal to the face in which the hole lies normalToPlacementPlane: normal to a defined plane (not specified) coaxial: coaxial with another hole (not specified) This is a Hole Feature. It may consist of a number of actual holes, each of which has the same sequence of Components (HoleComponent, CounterSink, CounterBore), but which may have differing positions and directions. Attributes: direction: Direction of of the hole. This direction defines the reference direction when evaluating the sequence of hole, countersink and counterbore elements; and the extent/offsets values within those elements. Individual HolePosition elements may override this direction. sequenceRefs: The sequence of HoleComponent, CounterSink and CounterBore elements that make up the complete hole description, in order along the Hole axis. These elements must be sub-elements of this HoleFeature. orientation: The orientation of the hole with respect to the starting geometry. This is for information/presentation purposes. Elements: HolePosition: One HolePosition element per actual hole. At least one. HoleComponent: Definition of a HoleComponent CounterBore: Definition of a CounterBore component CounterSink: Definition of a CounterSink component This is a Thread Feature, not associated with a Hole. Only a single position and direction can be specified. Attributes: position: Position of the start of the thread in global 3-space coords direction: Direction of the thread. This direction defines the reference direction when evaluating the sequence of thread elements; and the extent/offsets values within those items. sequenceRefs: The sequence of thread elements that make up the complete thread description. These elements must be defined as elements within this thread description. inside: 'true' if a thread feature on the inside of a hole, 'false' if a thread feature on a boss. setting The thread entry setting. Elements: Thread: Definition of a thread component. More than one is allowed. This is a collection (sequence) of Features. Attributes: firstFeature: The first feature in the sequence. ownerRef: Reference to owning ProductRevisionView or Representation. Elements: Feature: A HoleFeature or any other elements derived from Feature. validate=skipName