# Relation in sketch: to dynamically update in pattern?

Question asked by Roy Derks on Aug 11, 2014
Latest reply on Aug 12, 2014 by Jamil Snead

Dear Sir / Madam,

I'm not a real CAD engineer (I am actually a system architect), but use SolidWorks to validate some concepts / principles. Now I have a rather elementary problem, for which I would like to ask your help:

I have a problem regarding a relationship between two dimensions in a sketch, which I want to dynamically update in a pattern feature, see the attached model. Here, I have sketched a fiber with diameter 0.145mm, where the horizontal and vertical "radius" is equal to 15.350 mm from the origin (so this is the 1: 1 radius). Now, I would like to create a pattern of this "bent fiber" with a pitch in X of 0.25mm, where the Y position will shift 0.17mm. In order to realize this, I already have drawn the fiber as  quarter elipse, where the y-radius is made dependent on the x-radius.

See "sketch 1" in this model attached ("first fiber"), the above idea works (vary the horizontal dimension to a value > 15.350 mm, then it runs nicely along the vertical proportional to the 0.25/0.17 ratio, also see model "last fiber"). Then the following steps seemed simple to me: just make a sweep, and then "pattern" in x-direction and "vary sketch" so that the y-dimension is changed dynamically during the pattern formation. Unfortunately, this does not work, the vertical size remains at the initial starting height of 15.350 mm and does not increase according to the relation I have put in the sketcher

From my past, I am quite experienced in the application Pro/ENGINEER (Wildfire, all possible courses done) where the below issue was easy to solve this problem with the above method. Unfortunately for SolidWorks this method does not work. Any suggestions to make this work easily in Solid Works?

Thanks for your efforts!!!

Roy.