MechDesigner Glossary-EN

MACHINE MODEL

Model

The Model Element at the top of the Assembly-Tree in the Model name-tab.

Model Frame

The Model Frame is fixed. It is the 'absolute ground'. This is also called the Machine-Frame. Compare to Mechanism-Editor

Model-Editor

The working environment to see the Solids in the Model. You can also add Planes and new Mechanism-Editors to Planes.

Model graphic-area

The workspace that shows the Solids in all of the Mechanism-Editors.

Model name-tab :

The left-most tab at the top of the Model graphic-area. There is only one Model name-tab.

Model Triad :

The X (Red), Y (Green) and Z (Blue) axes at the Origin (0,0,0) of the Model.

Mechanism-Editor

The editor we use to build kinematic-chains with Parts, Joints, Cams, Gears, Belts, ... Kinematic-chains = Mechanisms, Linkages.

Mechanism graphic-area :

The workspace for each Mechanism-Editor

Mechanism name-tab :

The tab gv at the top of the Mechanism graphic-area.

Mechanism Origin :

The 0,0,0 of each Mechanism-Editor. The +X-axis is horizontal in the front-view.

The Base-Part has the same Origin and +X-axis direction as the Mechanism-Plane

Master-Machine-Angle (MMA) :

The Machine Angle is from 0 to 360. The position of all Parts are a function of the MMA

Machine Cycle

One cycle of the Master-Machine-Angle from 0 to 360

Part-Editor

Part-Editor

The environment to edit Parts to add sketch-elements, sketch-constraints and dimensions

Part

Parts are the physical elements in a machine. For example: Piston, Connecting Rod, Crank-shaft, ... are all Parts.

Part name-tab :

The Part name-tab name replaces the Mechanism name-tab when you edit a Part.

PLANES

Plane

A flat surface defined by two axes.

Mechanism-Plane :

The XY-Plane of a Mechanism-Editor.

The Front-View of the Mechanism-Editor is perpendicular to the Mechanism-Plane.

Part Plane :

The Part-Plane and the Mechanism-Plane are co-planar. However, the X-axis of a Part is from the start-Point to its end-Point.

ORIGINS AND AXES

Model Origin and X, Y, Z-Axes :

Global, Machine Frame axes in the Model-Editor.

Mechanism Origin and X, Y, Z-Axes :

The same as the Plane and Base-Part Origin and Axes.

Part Origin and X, Y, Z-Axes :

Origin at the start-Point of the CAD-Line; X-axis along the length of the CAD-Line. The Z-Axis is normal to the Mechanism-Plane and Part-Plane

PARTS

Part

Parts are the physical elements in a machine. An important element in each kinematic-chain. We also call a Part an 'Added-Part', Completely Free-Part, Free-Part, 'Connecting-Part'

Base-Part

The fixed Part and axes in the Mechanism Frame. The Origin of the Base-Part is the same as the Mechanism-Plane.

Connecting-Part :

A Part we join to other Parts with Ball-Joints.

Added-Part :

Added-Part is a Part, not a Base-Part.

Geared Rocker Part

The Part that has its motion specified by the input motion to the Gear-Pair, the ratio of Gear Teeth in the Gear-Pair, and the selection of internal or external mesh.

Part-Outline :

The SYMBOL used to identify a Part in the Mechanism-Editor. You cannot edit the shape of the Part-Outline.

Derived-Names for Parts

Motion-Part :

A Part in a kinematic-chain whose position is specified with a Motion-Dimension FB.

Rotating-Part :

A Part joined to a different Part with a Pin-Joint.

Sliding-Part :

A Part joined to a different Part with a Slide-Joint.

Translating-Part :

A Part that moves in a Plane and does not rotate. It may be a Siding-Part, but not necessarily.

Reciprocating-Part :

A Part that slides back and forth along a Line and does not rotate. It does not Index.

Oscillating-Part :

A Part that rotates back and forth about a Pin-Joint. It does not Index.

Indexing-Part :

A Part that moves progressively in the same direction. Usually, the Part moves then Dwells, and repeats.

Kinematically-Defined Part :

A Part that has a mobility of zero. It has a Green Part-Outline

Free Part :

A Part that has a minimum of one degree-of-freedom. It has one joint with a different Part. It has a Blue Part-Outline.

Completely Free :

A Free-Part that does not have a joint with any other Part. It has a Blue Part-Outline. It has three degrees-of-freedom.

JOINTS

Pin-Joint

Revolute Joint :

It makes a Point in two separate Parts align; the Mechanism Planes align. -

Identical to a Revolute-Joint

Slide-Joint

Prismatic-Joint :

It makes a Line is two separate Parts coincide; the Mechanism Planes coincide.
Identical to a Prismatic-Joint

Ball-Joint

Spherical-Joint :

It makes a Point is two separate Parts coincide; the Mechanism Planes do not coincide.
Identical to a Spherical-Joint

Magnetic-Joint

A joint to force a circular Profile to contact an irregular Profile (or Curve derived from a Point-Cloud).

CAMS

2D-Cam

A Cam that can be shown on one Mechanism Plane.

3D-Cam

A Cam that cannot be shown on one Mechanism Plane.

Cam-Plate :

The parent to a Cam in the Assembly-Tree. It can be a parent to one or more Cams.

Cam-Follower :

The Profile/Extrusion* of the sketch-loop that defines the shape of the Cam-Follower, which is in continuous contact with the Cam surface. The Profile/Extrusion is a child to a Part.

Cam-Shaft :

A Part, with a Cam-Plate, that usually rotates continuously in one direction.

Cam-track/groove / Cam-Rib :

The space between Cam-1 and Cam-2 (the internal and external Cams).  may be a groove, slot or rib.

GEARS

Gear-Pair

The pair of gears that you edit to modify the number-of-teeth, the module, and the mesh.

Geared-Rocker

The kinematic element at the output of a gear-pair that is operated by the gear with a motion at the input to the Gear-Pair

Rack Driven Pinion :

Pinion Driven Rack :

The Rack and Pinion element is joined kinematically. Either the motion of the Pinion is found by the known motion of the Rack, or the motion of the Rack is found from the known motion of the Pinion.

Hence, in the Kinematics Tree, the terms are 'Rack driven Pinion', or 'Pinion driven Rack'.

BELTS

Pulley

A Rotating Part (Pulley) that either drives a Belt, or a Belt drives the Pulley.

Belt Driven Pulley :

Pulley Driven Belt :

The Belt and Pulley elements are joined kinematically. Either the motion of the Pulley is found by the known motion of the Belt, or the motion of the Belt is found from the known motion of the Pulley.

Hence, in the Kinematics Tree, the terms are Belt driven Pulley, or Pulley driven Belt.

DIMENSIONS

Dimension

A distance, angle or length

'Static' Dimension :

A Derived Name. To imply the dimension does not change with time or machine angle.

Motion-Dimension

The Motion-Dimension identifies the Part we will move with a specified motion. We call the Part a Motion-Part.

Measurement Dimension

A driven* dimension between two sketch-elements. You use a Measurement FB to measure in the Mechanism-Editor. (*Driven: we can only observe and analyse its value). The Measurement also gives its first and second derivatives.

Reference Dimension

A dimension that gives a measurement between two sketch-elements that are in two separate Mechanisms

FUNCTION-BLOCKS : FB

Function-Block ( FB )

Each Function-Block has an output-connector that provides motion-values that can be connected to the input-connector of a different FB. The motion-values at the output-connector are a function of the motion-values at its input-connector, the MMA or the measurement taken from a different kinematic-chain.

We use the acronym FB for Function-Block in the help text.

Linear-Motion Function-Block

'Clock'

A FB whose output mirrors the Master-Machine-Angle (MMA). You can change the phase of its output relative to the MMA with the Linear-Motion dialog-box.

Motion FB

A FB linked to a motion in MotionDesigner. The motion-values at its input-connector correspond to the X-axis of the Motion with which it has a link, and the motion-values at the output-connector correspond to the Y-axis of the same motion.

Gearing FB

A FB to apply a simple mathematical function to the input. You can also add a number before and after you multiply the input with the ratio.

Motion-Dimension FB

The Motion-Dimension identifies the Part you will move with a specified motion.

Motion-Path FB

The Motion-Path FB identifies the Sketch-Element in a Part, to which we add a Point at the origin of the sketch-element. A Motion FB will define how the motion moves along the sketch-element.

Point-Data FB

A measurement of a Point – it gives X and Y coordinate motion-values. (Position, Velocity and Acceleration) and also the Magnitude of the Point's motion. The Point-Data can also be used as an independent variable for other FBs.

Measurement FB

A measurement between sketch-elements; to give motion-values. You can use Measurement FB data as an independent variable for other FBs.

Cam-Data FB

A FB linked to a 2D-Cam to calculate Cam-Coordinates and provide data for Cam Analysis.

Graph FB

A FB to show data during a machine cycle

Spring FB

A FB to apply Force between two Points

Force-Data FB

A FB that provides Force or Torque data, at a Point or a Motor.

Design-Set FB

A collection of Dimensions and Motion-Dimensions from different Parts.

Maths FB

A FB to do mathematical functions based on the input variables and parameters.

Stats FB

A FB to do Statistics based on the motion-values at its input-connector

Polynomial Fit FB

A FB to fit, mathematically, with polynomial functions.

3D MODEL ELEMENTS

Solids

The name for the Profile/Extrusion we add in MechDesigner, and also a Solid we can import from 3D-CAD.

Profile

Two contours that are offset from the Mechanism-Plane. The shape of the contours mirrors a sketch-loop in a Part.

Extrusion

The filled space between the Profile contours. The extrusion also has other properties: colour, transparency, density, moment of inertia, mass.

Auto-Profile

A convenient Profile; a sketch-loop and a Profile added to a mechanism with one command - Add Auto-Profile.

Hole

A cut through an Profile/Extrusion

TOOLS

Element-Properties

A dialog to show the exact element properties.

Trace-Point

The locus of a Point that shows on the Mechanism-Plane

Briefcase FB

A tool to put other FB inside - to make the model easier to manage.

DXF ELEMENTS

CAD-Line

A Line used to link with a DXF Drawing or STL File.

DXF File

A file that you import (open). It has the standard DXF format.

DXF-Element

A DXF element in the Assembly-Tree, put there after you open a DXF file

DXF Outline :

A complete DXF Drawing in the graphic-area. You cannot edit it.

DXF Entity :

A single line, arc or circle entity in a DXF Outline. You cannot edit it.

DXF Drawing

An external DXF Drawing. You can edit it with other CAD.

DXF Layers

A 'sheet' in a DXF Drawing. You can show or hide each DXF Layer.

DXF Origin

The origin of the DXF drawing in the original CAD drawing.

CAMLINKS MEC

Camlinks Outlines

DXF, or Polyline, that was imported into a Camlinks model, and subsequently imported into MechDesigner. You cannot edit a Camlinks Outline.

KINEMATIC TERMS

Kinematics-Tree

One of three trees in the Project-Explorer

kinematic-chain

Parts joined with Joints, with a minimum of one joint to the Base-Part.

Kinematically-Defined Part :

A Part in a kinematic-chain with a Mobility of Zero. It has a Green Part-Outline

Kinematically-Defined Chain :

A kinematic-chain with only kinematically-defined Parts. All of the Part-Outlines are Green. Each kinematically-defined chain has mobility of zero

Kinematic-Pair

A Joint: Lower-Pairs, Higher Pairs and Wrapping Pairs

Part

Perfect Rigid Body. It has an exact length.

Rocker

Motion-Parts: A Part joined with a Pin-Joint, and its motion is specified by a motion-values at the input-connector of a Motion-Dimension FB.

Slider

Motion-Parts: A Part joined with a Slide-Joint, and its motion is specified by motion-values at the input-connector of a Motion-Dimension FB.

Geared-Rocker

A Part whose position is determined by the motion at the input gear (drive gear), the number-of-teeth on each gear, and the mesh (internal or external)

Revolute-Joint (Pin-Joint)

Pin-Joint: A Joint with a Point in two different Parts that are made to be coincident

Prismatic-Joint (Slide-Joint)

Slide-Joint: A Joint with a Line in two different Parts that are made to be coincident.

Spherical-Joint (Ball-Joint)

Ball-Joint: A Joint with a Point in two different Parts - that can also be in a two different Mechanism-Editors - are made to be coincident.

Dyad :

Each Dyads has two Parts and three Joints

R-R-R Dyad

Planar Dyads

The two Parts in a Planar Dyad lie on one Mechanism-Plane.

The joints are Pin-Joints or Slide-Joints.

R-R-P Dyad

RPP Dyad

RPR Dyad

PRP Dyad

SSR Dyad

Spatial Dyads: One Part lies on a Mechanism Plane; the other Part in the Dyad joins Parts in two different Mechanism Planes.

SSP Dyad

RAM-R

Dyad that uses a Motion-Point to guide a Point.

RAM-P

Dyad that uses a Motion-Point to guide a Point.

Kinetostatic Force Terms

Force

The force needed to drive Parts with the motion given to them, given their Mass, and inertia, and any external Force applied to them.

Torque

The moment that is needed to rotate a Part with the motion given to it and any other Parts joined to it.

Project-Explorer

Project-Explorer

To the left of the Graphic Area

Selection-Window

Identify the elements you select in the graphic-area or the Assembly-Tree

Command-Manager

It provides hints or instructions for the active command. It may also open a short dialog, where you need to select one or more elements, to complete a command

Element-Explorer

List the Elements in the Model in various formats

Assembly-Tree :

A hierarchical and chronological List of the Elements you have added to the model

Kinematics-Tree :

A list of the kinematic-chains with Motion-Parts, Dyads and Geared-Rockers that may be in each Kinematic-chain

Geometry-Tree :

A list of Constraints and Dimensions in the sketch-elements. It is only available when you use the Part-Editor.

Feedback-Area

Message Area

The Area below the graphic-area. It gives you information, warnings and errors for each command that fails to complete.

Hints and Instruction

The hint, with a short instruction, of the active command, or the command as you move your mouse-pointer above a command or tool.

Animation Speed Slider

Tool to speed up or slow down the animation

Force Vector Scale

Buttons to increase or decrease the length of Force Vectors

Torque Vector Scale

Buttons to increase or decrease the length of Torque Vectors

Velocity Vector Scale

Buttons to increase or decrease the length of Velocity Vectors

Acceleration Vector Scale

Buttons to increase or decrease the length of Acceleration Vectors

Master-Machine-Angle

The Machine Clock.

'Revs'

Number of revolutions of the Machine.

ELEMENTS IN THE Part-Editor

Dimension

A 'Static' Dimension. Note : it is possible to make a dimension to be a 'Motion Function'.

Dimension Tool

Use the dimension tool to add a Static Dimension: between Points, two Lines, three Points, a Line and a Point, the Length of a Line, the radius of a Circle

Sketch-Elements

Line

A Line has a point at each end - the start-Point, at the Origin of the Line, and the end-Point

Arc

An Arc has a Point at each end, and a centre-Point.

Circle

A Circle. It has a Point at its centre, called the centre-Point.

Point

A point is a Point!

start-Point :

The Point where you mouse-button-down at the start of a Drag to add a sketch-element or Part

end-Point :

The Point where you mouse-button-up at the end of a Drag to add a sketch-element or Part

centre-Point :

The Point at the centre of an Arc or a Circle

Blend-Curve

A 'spline' that you can edit, at each end, its angle, curvature and rate of change of curvature.

CAD-Line

A Line that you can use to link and show a DXF Drawing, a SOLIDWORKS, or STL files.

Polyline

A shape that mirrors the shape of a 2D-Cam or Gear-Pair.

Spline

A shape defined a series of 'nodes' with curvature continuity at and between the 'nodes'.

Reference sketch-element

A sketch-element copied from a different Mechanism-Editor. It is orange.

Sketch-Element Constraints

Coincident

To make two Points, two Lines, a Point and a Line, or a point and X-axis or Y-axis to be at the same location or along the ray of the line or axis.

Concentric

To make two Circles, Arcs, or a Circle and an Arc, have the same centre-point.

Equal

To make two Circles or Arcs, or two Lines, have the same radius or length.

Parallel

To make the Points at the ends of two lines, or a line and an X-axis or Y-axis, to be equally far from each other.

Perpendicular

To make two Lines, or Line and an X or Y-axis perpendicular.

Mid-Point

To make a Point join to the mid-point of a Line

Tangent

To make a Line and Circle or Arc tangent, or a Circle and a Circle tangent.

Horizontal

To make a Line or two Points Horizontal.

Vertical

To make a Line or two Points Horizontal.