13 Replies Latest reply on Apr 6, 2015 4:23 PM by Mike Pogue

negative dimensions in sketchs or mates

Tom Mathieson Sep 17, 2007 7:08 PM

i'm sure this has been brought up before, but why does solidworksnot allow negative values in dimensions? this is somethingPro/E has had for years. it is frustrating, for example, ifyou want to flip a hole center about say a center line that it isdimensioned to.

in PRO/E, you would click on the dim, enter a , say -1.25,and the hole would move to the other side of center by 1.25.

in solidworks......... open the sketch, right click dimension,change to driven, move to approximate position, right click dim,change to driving, double click dimension, input new value, closesketch, rebuild

much simplier in Pro/E, IMHO. i've been trying to figureoutfor teh last 7 years why SW doesn't have this....

negative dimensions in sketchs or mates

Designer Designer Sep 17, 2007 7:44 PM (in response to Tom Mathieson)

Hi TOM...

I don`t know why solidworks not provide negative dimension. But in solidworks, you can use reverse direction. Or if you have solidworks 2008, you can use instant 3D. Instant 3D provide "negative value"

Regards,
DD
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- negative dimensions in sketchs or mates
  
  Tom Mathieson Sep 17, 2007 11:02 PM (in response to Designer Designer)
  
  Hi DD,
  
  thanks for the reply. i don't have SW 2008, but i wastalking more about dims in sketches. construct a simple holelike this, then flip it about center. in Pro, if my memoryserves me well, you would click and enter the neg number, andrebuild.
  
  in 2008, can you just drag the hole to left of center?? or enter aneg value?
  
  neg-dim.jpg 26.1 KB
  
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  - negative dimensions in sketchs or mates
    
    Designer Designer Sep 19, 2007 5:49 AM (in response to Tom Mathieson)
    
    Tom Mathieson wrote:
    
    Hi DD,
    
    thanks for the reply. i don't have SW 2008, but i was
    talking more about dims in sketches. construct a simple hole
    like this, then flip it about center. in Pro, if my memory
    serves me well, you would click and enter the neg number, and
    rebuild.
    
    in 2008, can you just drag the hole to left of center?? or enter a
    neg value?
    
    Hi Tom...
    
    In sw 2008, we can move the handle of a dimension.
    So not drag the center, we can drag the center only if the sketch still under define.
    I suggest you to call your VAR and see the demo of sw 2008.
    
    Sorry for the late reply.
    
    Regards,
    DD
    
    Note : dear sw 2008 users, please let me know if I wrong...
    
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negative dimensions in sketchs or mates

Kelvin Lamport Sep 17, 2007 11:50 PM (in response to Tom Mathieson)

I agree it could be handy, but till that day comes, you can constrain the hole to an offset plane. The planes offset can be reversed.

In Pro/E did the dimension show as negative when brought into a drawing view?
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negative dimensions in sketchs or mates

John Lhuillier Sep 18, 2007 10:20 AM (in response to Tom Mathieson)

You can drag the hole sketch to left of center with the dimensions intact if you have the OVERRIDE DIMENSIONS ON DRAG set to on. This is accessed under TOOLS>SKETCH SETTINGS. Then all the sketch entities will act like they do in Pro E until you locked the dimensions.
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- negative dimensions in sketchs or mates
  
  Tom Mathieson Sep 18, 2007 11:41 AM (in response to John Lhuillier)
  
  Kelvin,
  
  the negative sign does not show up in the dim. it just flipsthen shows up as a regular number.
  
  John,
  yes, you can do that, but you still have to open the sketch. inPro, you would just double click the feature, then change you dimthen rebuild.
  
  at least, that's how i remember it. any pro users out there?
  
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  - negative dimensions in sketchs or mates
    
    Mark Matthews Sep 18, 2007 1:50 PM (in response to Tom Mathieson)
    
    Yes, in Pro you can enter a negative number to modify an existing feature without having to edit the sketch. You can also enter zero.
    
    In SW I edit the sketch and drag an entity to the other side of the dimension root to flip it. Another thing I would love to see in SW that Pro does is to lock selected dimensions while editing a sketch. This way you can drag entites with critical dimensions as a whole.
    
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Re: negative dimensions in sketchs or mates

Ronald Plummer May 31, 2011 6:10 PM (in response to Tom Mathieson)

Hi Tom, I have also been waiting / asking / hoping for this feature.
As you all may see just like I can, the following enhancement requests (search: negative dimensions) are outstanding on this topic:
SPR 462735
SPR 464191
SPR 7055
SPR 415248
SPR 402112
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- Re: negative dimensions in sketchs or mates
  
  Kelvin Lamport May 31, 2011 11:27 PM (in response to Ronald Plummer)
  
  The negative dimension functionality was introduced in SW2009.
  
  http://www.mikescadblog.com/2008/08/solidworks-2-18.html
  http://www.javelin-tech.com/newsletter/tech/2008/august/article_zero_value.htm
  
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  - Re: negative dimensions in sketchs or mates
    
    Ronald Plummer Jun 1, 2011 12:39 AM (in response to Kelvin Lamport)
    
    Thank you Kelvin,
    I was somewhat aware of these techniques while sketching and I think they're useful.
    However, my ultimate request or hope is that I can use a design table to drive dimensions.
    And as of today (SW 2011 SP 3.0) I still get the error msg: "The vaule must be between "0.000000 and 39370.078740"."
    If you know of a work around I am interested, thanks again for the reply!
    
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    - Re: negative dimensions in sketchs or mates
      
      Matt Bracht Apr 3, 2015 11:43 AM (in response to Ronald Plummer)
      
      It's been some years since this post but....
      
      Has any solution been found? I am running into the same issue and I'm shocked this functionality isn't available.
      
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      - Re: negative dimensions in sketchs or mates
        
        Jody Stiles Apr 6, 2015 1:27 PM (in response to Matt Bracht)
        
        Hi Matt,
        
        It looks like there is a bug in the system when it comes to maintaining the negative values in a Design Table that has not yet been addressed. You can enter the values as negatives but the Design Table then makes the dimensions positive and changes the previously positive dimensions such that they are positive on the same "side" as the previously negative dimensions when changing between configurations.
        
        Please see SPR 471285 and vote for it if this is the issue you are having.
        
        Jody
        
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    - Re: negative dimensions in sketchs or mates
      
      Mike Pogue Apr 6, 2015 4:23 PM (in response to Ronald Plummer)
      
      I started a post on this a few years ago. I don't think it's a bug, I just don't think SW supports it. Also, if you have a zero in a design table, the results are very unpredictable.
      
      Reverse dimension direction in design table
      
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