Sketching NURBS on foamware models?

How many designers out there sketch directly on their foamware models prior to building in CAID?

I have an idea for a set of shorthand editing notation that could be used in conjunction with the boundary curves to help communicate surface details (ie. more than just the curves) things like:

Right angle ( _| )
Tangent ( -T- )
Trim (- - - -)


These symbols would be drawn over the boundary lines or in the center of particular areas to help the designer (or separate CAID modeler) better understand the design intent and to pre-plan construction. 2D sketches could benefit from this notation as well. Other symbols could define parent-child relationships for parametric modelers.

Anyone doing anything like this now?

As an extension of the idea, If a standard set of symbols were adopted by the industry, CAID software could include the symbols in the wireframe as well.


shorthand huh? How’s that going. did it ever develop into something?

Solid Edge has small symbols in the Sketcher similar to what you are asking.

When using the sketcher however, it is really tough to get the design intent to work correctly. The intellisketch functions can often give a math error.

Sometimes it is easiest for me to have only a portion of a prototype made and then do exactly what you are asking. Draw directly on the material to be removed.

Bouncing back and forth from a sketch on paper to a roughed out prototype is easier said that done.
I find it really is more about relationships. Some guys in shop are good with programming the lathe. Some guys are good at copying a curve from a pre-existing part, Usually I just need to know the right guy for the task I need done.

But back to your proposal of a standardized nomenclature. I think you are on to something. Adding it to a CAID package would help make sure the end result is achieved.

I think it is important to recognize that you are describing something bigger than old school GD&T drafting skills. It is the way a curve is made or transformed in the computer.

A recipe of sorts to control the parent child relationships in greater detail. This is very important because whem a computer part file has been through the fourth upgrade in the same brand of software, there is no recipe of when, where or why a curve is tangent or not.