Foreshortened Diameter Dimension

Foreshortened linear diameter dimensions are not specifically supported by ASME Y14.5M-1994.  I don’t know if “ASME Y14.5M-2009” will have such support added.  Even if not, there is a common practice of showing foreshortened diameters.  SolidWorks supports the two most common delineations for these.

To have a foreshortened diameter dimension, the diameter being dimensioned will have to be cut off in the view.  This means effective use of these is pretty much limited to detail views, since this is likely to be the only place one would normally use such dimensions.  I may try to experiment in the future to see just how far I can stretch SolidWorks functionality in this area, but for this article, I’m going to stick to the basics.  Please note that these instructions are SolidWorks 2009 based.  Steps will be similar in older versions, but may not be exactly the same.  They will be close enough to make this a good guide, though.

Preparation

To employ a foreshortened diameter dimension, there is some preparation needed within the model.  You cannot just insert your model into a drawing and add a non imported dimension onto a circular feature.  Because of the way Hole Wizard functions, foreshortening will also not work for holes created with it. Why?  I’m not sure as to the reasoning.  I just know SolidWorks only enables this function for imported dimensions (dimensions inserted from model).

  1. Start a sketch in your model.  This sketch will become your feature.
  2. Draw a circle.
  3. Dimension that circle as a linear diameter dimension.  This will not work if the dimension is radial.
  4. Make sure this dimension is set as mark for drawing.
  5. Create a feature from the sketch.

On the drawing

Insert the model onto a drawing.  Create a detail view which cuts across a circular feature.

Cutting the Detail View

Detail A

Once the drawing is set up, here are the steps.

  1. If the center of the circle appears in the detail, select the detail view by LMB clicking it.  If the center does not appear in the detail, then select the parent view instead.
  2. Insert model items.  This can be done by Insert pulldown>Model Items.  One of the dimensions to appear will be the diameter of the circular feature.
  3. Click OK in the PropertiesManager Pane to accept and close Model Items panel.  If already in the detail view, you are done.  The dimension will appear as a foreshortened linear diameter dimension.  However, if working in the parent view, a few more steps are required to get the desired effect.
  4. Hold down the SHIFT key.  Select the diameter dimension by clicking and hold the LMB over it.
  5. Drag the dimension in the detail view.  Let go of the LMB and SHIFT key.  This will copy your dimension into the detail view. The dimension will appear as a foreshortened linear diameter dimension.
  6. Delete the dimension from the parent view.

What’s next?

SolidWorks is very particular about how it allows foreshortened linear diameter dimensions.  These steps must be followed exactly in the manner described here.  I wish SolidWorks made it easy to implement foreshortened diameter dimensions, including allowing them for non inserted dimensions.

Future articles on this topic will discuss styles of foreshortened delineation (how to get double arrows instead of the zigzag dimension line).  It will also discuss one work around so foreshortening can be applied to other types of linear dimensions, producing a result sometimes called clipped dimensions.

SolidWorks Technical Summit – Los Angeles, CA

The SolidWorks Technical Summit is coming to Los Angeles, CA on December 16, 2008!  A Technical Summit is a day long event that is is kinda like a SolidWorks miniWorld.  Included are sessions covering a wide range of SolidWorks topics to help users expand their knowledge and experience.  Technical Summits are held once a month at various locations throughout the United States and other countries.The line up of presenters for the Los Angeles Technical Summit beings promise of yet another powerful conference!

Presenters

One inside heavy hitter is Hari Padmanabhan, who is experienced in presentations for CosmoWorks, now called SolidWorks Simulator.

Another insider is Patrick Rainsberry, Territory Technical Manager, SolidWorks.  Mr. Rainsberry has been on the Summit circuit before, so he’s an experienced veteran.  He also can be seen at local SolidWorks User Groups from time to time, with demonstrations about the greatness SolidWorks’ current release.

As icing on the cake, several blog squad members will be presenting sessions about various topics.  These include (in no particular order) Mike Puckett, Devon Sowell, Matt Lorono (oh wait a minute, that’s me!), and Anna Wood.

Then, of course we have the serial presenters Casey Gorman, Phil Sluder, and Richard Doyle, whose tireless contributions make SolidWorks User Groups and Technical Summits even possible.

Return on investment

The great thing about the Technical Summits is that they are official SolidWorks Corp events.  They are only $40 to attend.  Attendees get to pick which sessions they will join.  Breakfast and Lunch are included (worth the price of admission alone).  If you are within the Los Angeles and San Diego areas, I highly recommend attending the LA summit!  If you are even within a 2 hour flight from Los Angeles (such as: San Francisco Bay Area, Sacramento, Las Vegas, NV, and Phoenix, AZ), I still recommend attending. If you are a supervisor with staff within these areas, I highly recommend sending the entire staff for the day.  They will easily come back with enough new knowledge to pay for the $40 and for the 1 day gone (and even the flight and one night hotel stay, if applicable), many times over.

I’ve mentioned in the past that similar type summits in other industries can easily cost $800 for the day, and the quality and diversity of those presentations may not even equal what you will find at a SolidWorks Technical Summit.  This is likely the best bargain available in the industry.

Sign up on the SWUGN website.  Click the black Register Now button near the bottom of the screen.  See you there!

Matching game

In the meantime, let’s play a little game.  Match the head shot below with each name here:  Richard Doyle, Mike Puckett, Devon Sowell, Phil Sluder, Anna Wood, and Matt Lorono.

Foreshortened Radius

Foreshortening a radius dimension on a drawing is easy.  The option to foreshorten a radius is found when the radius dimension is highlighted by looking under the heading of Display Options in the PropertiesManager pane.  (Note: this foreshortening option will not be available if dimensioning a full diameter within the view current view, even if the dimension is shown as a radius.)    Once this option is chosen, the radius dimension will appear foreshortened with a zigzag radial line.  The user can then adjust the shape and location of the zigzags, as desired.

 

Options

 

This is easy enough.  I am covering this basic how-to tip as a lead-in for the more complicated task of foreshortening diameter dimension in an upcoming article.

Foreshortening Dimensions (Radial, not linear)

[Updated to address changes in SOLIDWORKS 2016]

SOLIDWORKS provides for the foreshortening of diameters and radii dimensions.  Older releases of SOLIDWORKS didn’t allow for the foreshortening of linear dimensions (or clipped dimensions), except in break views where both ends of the dimension are visible.  When I first encountered this limitation years ago, I was concerned that SOLIDWORKS developers just simply overlooked this functionality.  After all, if one can foreshorten a radius, then why not a linear dimension?  I was even sure I could find examples of this already being done on other drawings in detail views.  I was trying to use an open ended dimension line with double arrows on the open end.  I may have actually used this method a couple of times back in my AutoCAD days.

But what didn’t SOLIDWORKS support this for many years?  The lack of foreshortened linear dimensions can be understood by reading ASME Y14.5M-1994 paragraph 1.8.2.2.  This paragraph established the foreshortening of radii.  Its title Foreshortened Radii seems to preclude these methods for linear dimensions.  But why?

The clue is the intent.  1.8.2.2. states that if the center of a radius is outside the drawing or interferes with another view, the radius dimension may be foreshortened.  Strangely enough, paragraph 1.8.2.2 does not specifically describe the just how foreshortening is demonstrated, other than to say the dimension line is radial to the arc.  It does reference a figure that shows radii centers repositioned with zigzagged radial and coordinate dimension lines.  The key is that the center of the radius is still within view.  The dimensions have known termination at both ends.

Allowed foreshortening of radial dimensions

There is an issue with using this methodology on any dimensions where the termination of both ends is not clearly shown.  Without both ends of the dimension in view (or known through some other way), there is no established way to determine where the dimension’s open end terminates.  It is an incomplete specification.  In other words, if I have a detail view and attempt to dimension to a feature not in that detail, the fabricator does not know the location of the other end of that dimension.  SOLIDWORKS previous limitation was not really a limitation after all.  It follows the drafting standards in a very logical way.

Disallowed foreshortening and diameter forshortening

Another thing SOLIDWORKS allows is the foreshortening of diameters.  Although this is not directly supported by the standards, it is common practice.  Unlike the foreshortening of linear dimensions, foreshortened diameters make sense since the other end of the dimension is known, even if it is not shown.  I’ll address foreshortened diameters in more detail a future article.

As of SOLIDWORKS 2016, foreshorten of linear dimensions is supported without restriction.  This was added for customers who still need methods to clip dimensions regardless to the issues mentioned above.

“Brand New Car”

In case anyone is in doubt, but not over finances, right now is a GREAT time to buy a car.  I cannot overstate this fact.  With the economic woes causing our system to collapse all around us, there are many opportunities for which to take advantage.  Stock market is one, if you don’t mind the rollercoaster ride.  Another way is in using one’s buying power for the big ticket items (cars in particular, but yeah, I’m sure boats and such are going for huge discounts too).

I recently traded in my old 2003 Acura TL Type-S for a 2009 Pontiac G8 GT.  As I began on this strange move months ago, I got asked “trade in an Acura for a Pontiac?”.  Yes, without reservation.  I waited to make this exchange until the end of Sept, and I’m glad I did because I got great pricing.  (OK, the reasons why I readily dumped my Acura for a Pontiac are best covered some other time.  I’ll just say that no one asks why once they see my G8 GT and ride in it.)  Anyway, the point is, right now is a great time to get some really great deals on the cars.

This isn’t a message to tell people “Hey, go out and support the American economy.”  This is a message saying “Now is the time to strike; to get the really great bargains.”  The consumer advantage is not limited to GM.  All the car companies are in pain right now.  As I shopped around in recent months, many of the dealers put on a brave face, but there is an air of desperation.  I guess a better way to put is that they are willing to actually deal.  No more dealer mark-ups.  I’ve actually seen quite the opposite.  Some brands are selling 2008’s for WAY under even the invoice price (prolly close to what is actually paid by the dealer).

Of course, if you invest your money, you might score a 3.0% yield CD, which is running at about 1/2 the current inflation rate.  You can try to time the stock market, but much bigger money is likely timing you instead.  If you are going to lose money, you might as well enjoy the ride (literally).