Driven variable in driven dimension?

andy_cate

Hi, I am a beginner in Onshape.  I have been experimenting with variables in my sketches, and have come across a problem.  I want to have a variable that is in a driven dimension.  Any help would be appreciated!

NeilCooke

You could also use the Measure Distance FeatureScript feature to automatically create your variable. 

Jake_Rosenfeld

Hi Andy,

You can use dimensions in sketches the same way you use them in feature dialogs, by using: #whateverYouNamedYourVaraible (a pound sign followed by your variable name)

3dcad

So you need variable that changes according to other changes in the model?

This is something that Onshape could improve a lot, you need to run also other dimensions with variables and calculate the missing value from those. You can't directly reference to existing dimensions and you can't change parameter value by adding parameter name to driven dimension (which would be pretty awesome though!).

So if you need to know where is midpoint of line. Add parameter L for line length and create another parameter Lmid= #L / 2

thomas_kozak

There is an improvement request which sounds like something very similar, see here: https://forum.onshape.com/discussion/comment/23570/
This would be a HUGE improvement in my opinion, especially for parametric designs.

NeilCooke

You could also use the Measure Distance FeatureScript feature to automatically create your variable. 

thomas_kozak

Ahh, Measure Distance is a rather nice workaround for this, thank you much!  - for linear measurements.  Any insight into how you might do something like making a line equal to a measured arc segment?

Jake_Rosenfeld

Hi Thomas,

There is also a Measure Length FeatureScript that works similairly

https://cad.onshape.com/documents/3b94cb37940c65d6eb867804/w/37d878fd02dc9e537e399972/e/2532eb32e49f33d7e990100b