SolidWorks 2014 introduces the ability to find and use virtual sharps on the on-the-fly while creating dimensions.
- Start any dimension tool.
- Right-click on model or sketch geometry
- Choose “Find Intersection”.
- Left-click on any model or sketch geometry that intersect the first selection.
- The Virtual Sharp element is automatically added, the point is automatically applied as a selection for the dimension tool.
See the attached video below (AVI will open, not an embedded video).
On-the-fly Virtual Sharps (AVI video)
The names for dimensioning methods within ASME Y14.5-2009 often do not match the common names. For example, what most of us call ordinate dimensioning is officially labelled as rectangular coordinate dimensioning. This can make finding information about certain dimensioning methods hard to find within the standard.
One dimensioning method that is particularly difficult to find is point location. A point location is where a point is located by the intersection of extension lines only. The method is known by so many other names.
- theoretical sharp corner
- theoretical corner
- theoretical sharp
- intersection point
- imaginary point
- virtual sharp
- and likely others as well
SolidWorks uses the term virtual sharp. SolidWorks offers a list of options for the delineation of virtual sharp (i.e., point location), which is found at Tools pulldown>Options...>Document Properties tab>Dimensions heading>Virtual Sharps subheading. The only method supported by ASME Y14.5-2009 is the use of intersecting extension lines from two surfaces; so called witness in SolidWorks.
The standard does not require any other identifier or labelling. Yet many of us do feel compelled to add some sort of label to the dimension, using one of the above terms or their initials. A label does add clarity, particularly when the scale of a view makes display of a point location hard to read.
I covered this topic once before from a slightly different perspective in this article: Virtual Sharps. That article includes instructions on how to create a virtual sharp in SolidWorks drawings.
In the past, I’ve settled on using the phrase “TO V.S.” after a dimension which is to a virtual sharp. I’ve seen this type of referencing used elsewhere. Another set of initials I’ve seen used is TSC, which I guess stands for theoretical sharp corner. I think this is likely older wording. I used to like the shorter “VS” myself because it refers to what I would consider a more common term. However, none of this matters too much since the standards say nothing about what is proper. ASME Y14.5-2009 uses the term Point Location, but doesn’t specify any identification symbols or abbreviations for this concept.
SolidWorks graciously offers a multitude of marks to create an identification of a virtual sharp. The main problem I run into with SolidWorks and this function is that I’m working in drawing scales or with radii sizes that frequently make such marker nearly invisible without a magnification glasses. The other problem is that none of the marks are identified in any standards. Heck, a third problem is that fact that the functionality is extremely hidden. You have to know how to make a virtual sharp mark because there’s not button, or icon specifically for it. It’s a short series of steps that would be nearly impossible to guess at.
Those steps being (within a drawing): 1) Select each of the two object lines that intersect in space. 2) Select the Point function. How is anyone to know intuitively to select the Point function? Hmm. Anyway, at least SolidWorks offers some method. That’s more than can be said about the standards.
I guess I should ask what are others doing to identify dimensions that are to virtual sharps?
Here is an updated article about Virtual Sharps.