sketcher equations...

[design-engine]

I have a need to drive a dimension in sketcher to an overall distance. Problem is I don't know how to dimension an existing distance in Solidworks. In Pro/E we call it a known dimension and it's relation (equation) would display a K for Known. I would just make my dimension equal to say 30 percent of the overall distance.

Help


Edited by: design-engine

 

[mjcole_ptc]

Hey Bart this one I do know.

In solid works it's called a Driven dimension and one nice thing about SW is that it lets you convert Driving Dimensions to Driven Dimensions and Back with out removing the dimension ID which might be used in other relations.

In Solid Works you just create the dimension to the Model Geometry outside of your sketch and you can select edges and other non sketch geometry and it will automatically be created as a Reference or Read Only dimension with a RD#@Annotations as it's ID.

In Sketch you cannot reference external geometry with out projecting it into the sketch first so select the edges you want to dimension to and hit the Convert Entities Tool. This will add these references as solid curves much like Use-Edge works in Pro/E and unlike Pro/E you can not use the edge for a feature by making it into construction geometry.
Convert Entities to dimension

Then to drive your 30% length you can use either of the following but I'd suggest using the annotations Read Only method
"D#2@SketchA" = .30 * "D#1@SketchA" 'Add Description
Driven Dim in Sketch
"D#2@SketchA" = .30 * "RD#@Annotations"
Known Dimension Annotation

Entered Relation 'In Solid Works you can add comment on Same line using a single quote followed by text. It sure beats /* in Pro
By clicking [Comment] button in the Tools > Equations window this will be done for you and it's quite convenient.

While in Sketch you can select the relation you want to drive then Click the Σ icon on the Tools bar or select Tools > Equations and hit Add. This will automatically type in the Dimension ID and enter an = sign and you can select the Driving Dim on screen for it to type in that dim ID with the quotes before and after the id which SW requires "". The quotes are kind of a pain when typing relations in but That's why I choose to select them on screen.

Visibility of the Reference or Known Annotations dims can be set by right clicking the Annotations folder in the Feature Manager.

To change the Driven or Read only states or Dim IDs in the Sketch select the dimension or hit Alt+r when the Dimension Tab is up as a shortcut to More Properties.

Michael




Edited by: mjcole_ptc

 

[design-engine]

well thanks so much mjcole_ptc. I knew how to do that one. I want to do it in the sketch.

How do you copy a sketch in SW and get the feature to retain the dimensioning scheme with dimension intact?

 

[design-engine]

and it takes two times to regenerate the model with equations. That kinda sux

 

[mjcole_ptc]

I had not tested the following out otherwise I wouldn't have recommended it.
I edited my original post to explain more completely how to do the dimension in the same sketch.

and it takes two times to regenerate the model with equations. That kinda sux

Bart,



Are you talking about the Read Only Annotations Dimension method or the other one I described. I assume you mean that the Annotations update after first Regen and then the equation updates the second time. Or have you tried the Convert Entities option.


Does the length you are looking for exist in another previously made
sketch? You can use that to drive your relation or create the
dimension in the same sketch using the Convert Entities icon which
works much like Pro/E except SW requires you to use Object
Action for the command and gives you an error if you don't select your
references before choosing Convert Entities.

Select geometry you want to dimension.
Hit Convert Entities
Change geometry to Construction Geometry.
Create driven Reference Dimension to construction geometry.
Enter equation to drive the new length by the Known Dimension that you just created in the same sketch.

If that requires 2 Regenerations then I'm perplexed.

Michael

Edited by: mjcole_ptc

 

[design-engine]

ok... leme see