學習要點 :
Lesson on degrees of freedom
An introduction to assembly Mates
Mate Connectors
Manipulating part position with the triad
Explaining Mates and Relations
Animating Mates
An introduction to Linked Documents
Applying limits to a Mate
Assembly and Mate Connector
For designing and manufacturing an assembly, it is important to know which parts go into the assembly, how many of each, how they are assembled, and how they should perform.
A Mate in Onshape fully describes how two parts will interact with each other by specifically controlling each degree of freedom through the use of things called Mate Connectors. You can think of a Mate Connector as a small, local coordinate system (an x, y, and z axis) for a joint between two parts. The Red line is the X-axis, the Green is the Y, and the Blue is the Z.
Animations
Animations are a great way to view the motion of your Mate before accepting it. Onshape will automatically move the Mate in a way that will exercise the Degrees of Freedom. In a Revolute Mate the part will rotate, in a Slider Mate, the part will slide, in a Cylinder Mate, the part will slide and rotate, etc.
Relations and Limits
A relation is a way in Onshape to constrain degrees of freedom between two Mates. Where a Mate controls how many degrees of freedom a pair of parts has between them, a Relation can control how those degrees of freedom move with respect to each other. There are 4 types of Relations in Onshape: Gear, Rack and Pinion, Screw, and Linear. These relations rely on preexisting Mates to define the type of motion that will occur between two parts.