Axis system versus Planes

[vsawye2]

i'd like to know what you all prefer and why. using mostly axis systems or planes to sketch on. i've been using catia for a few years now and have had several classes, i come from an I-deas background. i've been told in one class to use planes and never use the axis systems because they are unreliable, on the other hand, in a recent class i was told you should always sketch on an axis system. i'm curious, whats your two cents?

 

[jackk]

Where I work, we follow these guidelines.

1. Only use Positioned Sketches, because they provide associativity. They can be based on Axis Systems or Planes.
2. Use multiple Axis Systems to identify major components and features, because they can be repositioned.
3. Never use the primary planes (XY, YZ, ZX), because they cannot be repositioned.
4. OK to use user-defined planes

We have never experienced problems with Axis Systems - that instructor didn't know what he was talking about! A single Axis System provides 3 planes, 3 axis, and an origin point.

We do use a "skeleton" methodology for relational design, but we do not use the contextual design features in CATIA.

 

[PeterGuy]

Axis systems are not unreliable in my experience. However when you use a plane or a direction from an axis system you are making a reference to a sub element of the axis system, which is by definition less stable than a reference to the whole object. That said as you cannot change an axis system other than moving it about it is very unlikey to rename its internal elements and therefore links made to its sub elements are unlikey to fail.

 

[m1mason]

I find myself using planes more than axis systems as they are easier to create and manage.

I will, however, use Axis systems extensively when detailing aerospace parts. Because most of the components have a master axis system that they tie to (which can be a mile away), I need to create a local axis system on the part to generate proper holes tables and coordinates in 2D drafting workbench.

http://mtm-cadtutorials.blogspot.com/

 

[tbuelna]

Both have their uses.

To me, planes seem to keep the model a little less cluttered. On the other hand, having multiple axis systems is very handy when you are setting up loads in an analysis file.