CAD Craft

A resource to CAD Craft specialists, and a showcase of my work — in both material and virtual worlds

Archive for CNC

CAD Tips: Sweeps

In engineering design of machined parts, there is often a misunderstanding of meaning when someone uses terms like ‘economical or low cost design’. Conditioned to think of cost in terms $$, many often overlook the factor of time, most significantly in the context of machining steps — operations, iterations, repeated passes, etc. Whatever we can do as designers to reduce the number of operations & iterations in the machining process saves $$$. This is what time study engineers do — analyze ways to streamline a task process. For instance making a series of circular features concentric — even when this may not be crucial to the design — can significantly assist those in the machine shop & inspection area to more swiftly and effectively complete their tasks.

One of the features which sometimes befuddles folks is the Sweep(in SolidWorks), whether an extrusion or cut. I will address some tips in this area. However, it is important to keep in mind that it is a mistake to presume that just because you can design a 3D model, it can be machined. It is also true that a feature you apply in a CAD design may not be able to be machined in an analogous process. For instance, a sweep along an edge of a circular part is a fairly simple lathe operation. However, a sweep along a polygonal part is more complex.  For some machining systems, working their way around a 4, 5 or 6-sided part is not so challenging.  For others, it is a harrowing issue. Allow me to reiterate: CAD is not a stand alone tool/premise/concept — it was always conceived as a partner in CAD/CAM = “Computer-Aided Design” & “Computer-Aided Manufacturing(or Machining)”.  Once you have completed your model and submitted it to the shop, they must go through a process of conversion to their CAM software to program their CNC machines to actually do the work.

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