Length of a curve

lloyd_snell

So I need to drive the design to a specific belt pitch length for a series of pulleys. There are 3 arc and 3 line segments. I need to get the length of all of these elements. 
1) Would be to select and get a value. Worst solution but I would get there.
2) When a change is made the new value is displayed. This what I did in Creo.
3) Would be a variable that is driven to maintain a certain value. Best Solution

ilya_baran

Here's a document with a custom Measure Length feature that will do #3 -- I adapted it from my Measure Distance FeatureScript example.
https://cad.onshape.com/documents/3b94cb37940c65d6eb867804/v/caa6335cb53dfae6f0cd3e33/e/2532eb32e49f33d7e990100b
Click on the plus-in-dashed-rectangle and select the Measure Length feature to add it to your toolbar.  To use the feature in your part studio, type the variable name and select the curves.  Post here if you run into trouble with these brief instructions.

connor_shannon

It would be really great to be able to add a custom constraint that sets an arc length equal to a straight line's length. I have been scouring featurescript, but it doesn't seem possible. This would basically solve all my problems right now. I am routing a belt around complex geometry, and I am having a hard time defining the length of the belt as it rolls off an irregular cam.

Is there a way to set line length equal to arc length as a custom constraint?
If not, can you think of a different way to approach this problem?