Q : What is draft(拔模), and for what manufacturing purpose is it mainly used?
A : Draft is when you add a small angle (1-3°) to any surface so that it may be properly(正確) manufactured using Plastic Injection Molding(注塑成型) processes. The draft angle is measured between the the surface and the direction of pull.
Q : Why are small radii common in parts that have been designed for plastic injection molding?
A : Adding small radii to sharp edges allows for the plastic to “flow” better during the molding process, and facilitates(有助於) easier removal(移除) of the part from the tooling after molding.
Q : What is a “Split(分裂)” feature?
A : It is when you cut a single part into multiple parts using a surface or plane.
Q : Explain a typical use of a Variable(變量) in Onshape.
A : A Variable is used to establish(建立) a design parameter, for example the thickness of a plastic part, that may be referenced throughout the design; in multiple features and parts.
Q : Explain what is going on in the “thickness(厚度)” entry of the dialog box below:
A : We are defining the thickness of the rib feature as an expression, 0.7 X “thk” inches, where “thk” is a previously defined variable in our model.