×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Reference Dimensions

Reference Dimensions

Reference Dimensions

(OP)
What is the best way to implement reference dimensions? I use this term cautiously, but I want to use a dimension that has been changed to reference to define some other component of my model. I cannot provide a file with an example, but I have attached a picture as a simple example. Note that I realize there is an easy solution in my example, but it is just to convey my issue.

Say I draw a cone with a base radius (P1 = 100). Then based on other criteria, somewhere along that cone, I need to use the radius. If I take a vertical constraint at that point (P2), it returns the radius. The model is now over-constrained unless I make P2 a reference constraint. Now say I want to have some line offset from the cone by P2. I set a constraint (P3 = P2), and it gives the correct offset. My issue comes occurs when the radius (P1) is changed; the P2 displayed value updates but the P3 offset does not. I'm not sure why I can put reference dimensions in a formula if they do not update, but it seems that is the case. So what is the best way to reference a value that is not explicitly defined?

I thought maybe this scenario is the purpose of having an option to "use measurement" in the formula definition. However when I try to use a distance measurement in my constraint for P3, I cannot select any lines in my current sketch. The only thing I have been able to do is duplicate all of that information in a separate sketch; then when I use the distance measurement, I can select the lines and get my radius. It does update when changes are made as well. It works, but this seems to be a very convoluted way to perform a seemingly common action. Is there a better option?

Thanks in advance

RE: Reference Dimensions

Rather then create an actual constraint dimension go ahead and create the point where you want is in the sketch and then leave the sketch and use a Measure Distance (with 'Associative' option toggle ON) to get the height of the point from the axis of the cone. Now you will have to create a second sketch for the parallel line, but then use the expression created by the Measure distance to control offset of the parallel line, as I did did in the attached example.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

RE: Reference Dimensions

hi..
thanks and this is best for it..

Mimnesh,

RE: Reference Dimensions

(OP)
That works out well. Thanks for the advice

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources