The Online Community About Exciting CAD Technologies
After consulting with R&D, it appears that it's not possible to make that change in one operation in SpaceClaim 2011 SP0. I trust they will make that easier in the near future. Will keep you posted.
In the mean time, your best bet is to delete and recreate the bend or use beam elements to model it.
If the bend axis was pickable, the issue could be dealt with.
-- Moving cylinder(s) would just move the bend position, keeping bend radius
-- Pulling cylinder or torus faces would change minor diameter, keeping bend radius
-- moving bend axis would change bend radius, keeping min.dia. and cylinder position.
The torus has always been a bit of a challenge for direct editing. There are several parameters that are involved with the torus; the angle, and the major and minor radius. With direct editing most tools can access and modify the angle, as Blake shows. Some can also modify the minor radius. It’s the major radius that gives some systems problems. When changing the “bend” radius in your example, you are changing the major radius of the torus. The reason that it can be difficult is that the edit will force other parameters to change at the same time. Either the adjacent faces have to move, or the center position of the torus has to move.
In my video example, Creo Elements/Direct (CoCreate) has the ability to work with each parameter in the torus independently. The user can also control whether the adjacent faces will move or the center of the major radius will move. To change the bend radius of the bar, I must fix the two adjacent faces, and then adjust the major radius. Basically in this example you have to be able to constrain geometry. Most direct editing tools don’t allow for this. Elements/Direct does have Cable and Piping functionality that makes this very easy. What I am showing is the manual method – something that would apply to any geometry – the part could be IGES, STEP or whatever, and there can be as many bends as you want. You can also group bends together so they always match.
Thanks for the video that was exactly what I looking for.
For the minor radius use the Offset function. To change the major radius requires some constraints - which are not available in the Personal edition - unfortunately.
So if it requires some constraints, this is not exactly a direct modeling approach any longer, is it?
Good question. I guess it depends on your definition of “direct modeling”. I think being able to control geometry is important in any CAD tool. Constraints in a direct model are very different than in a history-based model. In direct modeling constraints are applied directly to the 3D geometry and require a synchronous solver. They can be applied to any geometry regardless of where or how the geometry was created, and they can be added anytime. Constraints in a history-based system are applied in the feature/tree structure at the time of feature creation, not directly in the 3D geometry, and they are solved linearly. I think constraints that can be embedded directly in geometry any time and are solved synchronously fit very nicely with the direct modeling methodology.