CAD: Direct (Explicit) or Parametric?

[McAndy]

Evening. I've recently had a demonstration of a direct modelling CAD software, SpaceClaim, and I was very impressed by its speed and ease of use. It seemed like a mature product with toolbox libraries, a close working relationship with a workflow and PDM management system and GrabCAD integration if workflow isn't required.

I have been user of SolidWorks, Inventor and most recently Creo for a good few years now and I am wondering what parametric brings to the table that modern direct modelling cannot do?

I have read reports regarding it not being good for doing many configurations of one part: is this still true? A few places seem to combine both practices, direct for concept modelling and Parametric for Production, but I haven't been able to see why? I am in a medium size assembly business that subcontracts sub-component manufacturing.

Any recent (last 2 years) experiences would be gratefully received! I like to scenario test as much as possible before committing to a trial period. (I know that the trial software is free, but the IT and personnel time isn't.)

Let the debate begin!

[McAndy]

Insanity Magnet said:

Since this is still a bit quiet... I am a long-time user of SolidWorks (98+ onwards) that was getting a tad narked with the lack of product improvement and consistent quality. I ran a trial of Solid Edge last year to see if it could deal with the wide range of crud I deal with. This includes complex surfacing of consumer products, machine design, furniture and arty stuff. It took a little while to get my head around the basics of the synchronous modelling approach but started to make some headway with it (I had some time free so tried to recreate various past projects, or at least the challenging bits). I generally couldn't see many major issues with it, other than trouble adjusting models with complex filleting and some problems with how it dealt with extending and offsetting irregular surfaces (SolidWorks will fudge stuff in a manner that may or may not be acceptable). Didn't like the interface much, either (I know, I know SE is more "grown up").

The big(gest) problem I have with SolidWorks, and where I can see direct modelling being a god-send, is dealing with other people's models. The number of modellers that are incapable of creating a robust, easily understood and easy to debug model is quite worrying and damned irritating. "Too busy" is the excuse I frequently hear...

Indeed. We are also considering SW to replace Creo but the compatibility (or lack of) is a major issue. A direct modeler would remove any legacy issue there, as long as drawings can be handled, too.