Re: Vectorcam, bobcad, rhino3D, which one??

--- In CAD_CAM_EDM_DRO@y..., pavel59@y... wrote:

> John, I don't want to enter the dispute about the stand alone CAM
> packages, I agree, there're a few of them and the majority of them
> are very expensive.
> But about the 3D side, I want to make one thing clear: CAD doesn't
> necessairly mean 3D and viceversa. Drawing exchange doesn't mean
> surface exchange and so far.
>
> C.A.D. means Computer Aided Design (Drafting), usually mechanical

or

> architectural drawing, modeling and detailing
> A more recent definition like C.A.S. (Computer Aided Styling) and
> C.A.I.(D). (computer Aided Industrial Design) label those
> applications - like Rhino, Alias Studio, SolidThinking, Form-Z and
> few others - which are specialized in 3D modeling. These softwares
> usually support specialized features for advanced surface modeling
> and evaluating which are not available on general purpose or
> mechanical CADs.
>
> Some other high-end applications like ICEM and Imageware Surfacer

are

> also used in the automotive industry for C.A.S. but they actually

are

> Reverse Engineering applications.
>
> Rhino isn't a CAD package (ask McNeel if they would consider it a s

a

> CAD), it's a 3D surface modeler (with oustanding capabilities at a
> very low price).
>
> DXF isn't a format you would rely for exchanging consistent 3D
> surfaces, IGES, STEP and other more exotic formats are better

suited

> for this.
>
> If I was Mr. Tauseef and I had no access to the packages I actually
> have, but - at the same time - I really needed serious 3D work, I
> would consider a professional package like Rhino and would look
> around me for a CAM able to read any IGES, STEP or even a STL file.
>
> I remember a japanese site with lot of impressive examples of jobs
> done that way on small personal CNC mills, modeled in Rhino

(mostly)

> and processed into some inexpensive CAM software.
>
> In 3D, the quality of the source is the most important step: if you
> don't have a reliable surface to work, it doesn't matter which CAM
> package will process it.
> STL exchange format could be a good compromise, it gives you the
> choice for resolution/speed/time/precision you can afford and let

you

> use one of the affordable packages available today. Don't forget -

it

> has been developed for the high precision Stereolitography
> prototyping process.
>
> Finally, about those specific CNC operations and cycles you
> mentioned, I suppose you could machine your free-form surfaces the
> way I suggested and then, import those mechanical features into
> another apllication which better handles them.
> I feel this is a quite common procedure (at least I could see it
> being applied several times in professional machining).
>
> I hope my words are understandable, this isn't my first language

and

> I apologize for the mistakes.
>
> Paolo Velcich
> industrial designer

Paolo,
Thank you for the reply and I had no trouble understanding it. Your
english is 10,000 times beter than my Italian?
You are not entering into a dispute at all, that's what discussion
groups are for. I've left your post virtually intact and I'll try to
cover the replies in order.
Firstly though I don't want to appear to be knocking Rhino I am only
trying to give general answers.
I was lead to believe that DXF files can give 3D information hence
the DXF3D tag on some file names, Millwizard is one I believe.
Obviously not all prgrams can ouput these files.
Your remarks about CAS, CAI[D] and ICEM whilst being very valid are
really out of the scope of this list which is very hobby based.
The use of Rhino and a STL based cam system will give very good
results as you point out but this combination will then deplete Mr
Tauseef's funds leaving him nothing left to buy another package to
handle the other milling cycles, most of which will cost the same as
his initial purchase. So instead of paying $800 which I think was the
mentioned figure he will finish up paying twice that for four
programs, duplicating in cases what he needs.
You mention that in professional machining this is done but I've als
seen where a company has paid $15,000 for a CAD/CAM package, realised
that it doesn't suit them and are looking for another one.
I don't think anyone on this list falls within this scope.
We are all stabbing in the dark because Mr Tauseef laid down a very
open ended question. Until we get clarification on his proposed uses
we will be split between those offering Rhino / STL Works /
Millwizard / Rams/ Ampari and what I call full blown 3D CAD/CAM

Come on Tauseef we are fighting on your behalf and you aren't holding
your end up <BG>

John Stevenson
Nottingham, England.