While doing my Curves presentation at SolidWorks World, Iexposed a problem with constraining to projected curves. Here isthe entry that I put into the PowerPoint file and the link to thevideo to show how to do it:
When constraining to projected curves on surfaces or faces, wecurrent (in 2008 SP2) have a problem with overdefining whenconstraining 3D sketch splines to them. This occurs becauseprojected curves don't meet the ends of the faces that they projectto with sufficient accuracy that the 3D constraint-solver needs andit applies both a constraint to the end of the fore-shortenprojected curve as well as the edge of the face causing anover-defined condition. If you zoom in very closely on theconstraint, you will see this.
It is best to convert them to a 3D sketch curve that will overcomethis problem, or you can do the following:
Go ahead and create your 3D sketch spline to the projected curve/s.
When it goes over-constrained, zoom in on each end of the splineuntil you can notice the mis-match of the projected curve with theedge of the face.
Simply delete the dual constrain to the edge (not to the end of theprojected curve), and on either end if necessary, and this willremove the over-defined condition.
You can now successfully add tangent and equal curvatureconstrains.
To see thisClickHere
To play this video you might have to download the Techsmith codecfrom:http://www.techsmith.com/download/codecs.asp
SolidworksSketching
When constraining to projected curves on surfaces or faces, wecurrent (in 2008 SP2) have a problem with overdefining whenconstraining 3D sketch splines to them. This occurs becauseprojected curves don't meet the ends of the faces that they projectto with sufficient accuracy that the 3D constraint-solver needs andit applies both a constraint to the end of the fore-shortenprojected curve as well as the edge of the face causing anover-defined condition. If you zoom in very closely on theconstraint, you will see this.
It is best to convert them to a 3D sketch curve that will overcomethis problem, or you can do the following:
Go ahead and create your 3D sketch spline to the projected curve/s.
When it goes over-constrained, zoom in on each end of the splineuntil you can notice the mis-match of the projected curve with theedge of the face.
Simply delete the dual constrain to the edge (not to the end of theprojected curve), and on either end if necessary, and this willremove the over-defined condition.
You can now successfully add tangent and equal curvatureconstrains.
To see thisClickHere
To play this video you might have to download the Techsmith codecfrom:http://www.techsmith.com/download/codecs.asp
SolidworksSketching
