Hello Jerry,
06-Nov-96 14:05:21, Jerry Myer did write to Ian Underwood
      Subject: SDRC
 JM>> SDRC - just another overpriced, overdone program that is
 JM>> never a finished product.
 IU>> Interesting - the 3D version or their 2D version.
 IU>> It's a big commitment to buy one  3D package "over"
 IU>> another - evaluated a few.
 JM> Didn't know there was a 2D version.
  (That was where my reference to "Navigator" came in)
 JM> And they are "pricey".
 Appertaining to all 3D modellers and their wretched maintenance
 terms ?   (not sure where your comment fitted - just checking)
 IU>>  If anything I'd have thought the "never finished" bit applied  
 IU>> to all major programs including Acad but especially the their  
 IU>> modeller rendition ;-)
 JM>    Yes, so I look for tools that are as simple as possible.
 JM> Already been burned by Computervision.
 I see from the rest of your message that my wants are quite
 different - The main aim is to speed up the design cycle
 So good "publicity" type pictures show the marketing guys
 what the design looks like much earlier than "cutting metal"
 and I can send them "wordwide" easily
 And given a parametric modeller or equivalent, the "What if"
 and late design inputs can be readily tried without the pain
 of the major redraw suffered with conventional 2D like the
 Acad 9 to 12 we have used
 No need to visual difficult interfaces or worry about wall
 thicknesses as features are put in. Sections are a doddle
 As more prototype services become lower priced I will probably
 add the rapid prototype features to my desires, but that's not
 where the time (well MY time :-) is wasted at present.
 IU>>  The biggest (commercial) pressure came from ProE and it
 IU>>  wasn't nice to use at all.
 JM>  I thought ProE was a good demo, very powerful for making 
 JM>  pictures/design, but manufacturing is a completely different story.
 The strong area for me is in making design changes, also an
 important feature is being able to confidently pass a drawing
 to someone else. On some modellers this is fraught with danger.
 Unless the steps are able to be re-run and changes made
 (without having to re-model from the point at which the
 change is introduced......) It's worse if the "shape"
 was created in a novel way and the new operator cannot
 get his head round it, IYSWIM.
 IU>>  Now are you saying that I should consider Acad as a serious 3D  
 IU>> modeller? I want something slick and polished with a nice  
 IU>> interface that knows about surfaces, etc.
 JM>  Well, yes, I say you should consider it, depending on what your
 JM>  requirements really are. As for the slick interface, well that may 
 JM>  be what you want, but maybe not what you need. I got my AutoCAD R12 
 JM>  for $200 or so as a bona fide student in a night class. The whole 
 JM>  college tuition and all was about $1400. That got me into AutoCAD, 
 JM>  some instruction, and a couple of college hours. I tried to do some 
 JM>  work with DesignCAD 2D but it was more trouble than it was worth, 
 JM>  and I paid the same price ($200) for DesignCAD. In some respects 
 JM>  AutoCAD R12 surpasses Computervision capability that cost probably 
 JM>  about $1,000,000 a decade or so ago.
 I regard Acad R12 used for 3D work with loathing - I wont use it.
 I have no problems "driving" Acad in 2D - but I do want a 3D
 modeller
 Their (Acad) 3D modeller product is in it's infancy
 IU>>  I'm fed up with 2D modelling and having to draw complex 
 IU>> surfaces  and sections (particularly in side view) far better 
 IU>> these views  are auto drawn as soon as the depth information is 
 IU>> given.
 JM>    I don't follow the phrase "auto drawn". You may mean parametrics. 
 JM>  That is a nice design feature.
 I do, although the name and implementation varies from one
 package to another
 IU>>  Far better that a late design change doesn't mean a nearly  
 IU>> total redraw of /all/ views.
 JM> I have yet to see a convenient way to go from 3D to a 2D drawing.
 Nearly all the packages reviewed readily gave 2D "manufacturing"
 drawings the let down in the demos was the auto dimensioning etc
 and what tools were to be found if the auto features were not
 used.
 
 JM>  Fortunately, I usually just import geometry and machine it, rather
 JM>  than need to dimension it myself. But I have done some design work 
 JM>  and it takes considerable forethought and additional layering in 
 JM>  different views to do the right kind of modeling that appears as a 
 JM>  2D object in each view.
 That's saying that you pick up where I leave off 
 JM>   Solids make super pictures, very quickly. Blending of fillets is 
 JM>  often a nightmare, and sometimes just not supported in certain 
 JM>  cases. Unless you need mass properties, the solids representation 
 JM>  may not be of much real help. But this depends on the kinds of 
 JM>  toolpaths that are required. If you just need some "canned" routines 
 JM>  for running around mold surfaces it may be just fine. But if you 
 JM>  need 5 sided machining where you flip the part around on the table, 
 JM>  the graphics concept of copying and flipping the part geometry to 
 JM>  the machine reference system is not copacetic. What you get is 
 JM>  duplicated geometry, and as you mentioned, a problem in the case of 
 JM>  design changes. I prefer to use a single part representation, upon 
 JM>  which the tool path can be verified as a single setup
 Have to stop you there :-) That's not my line at all 
 JM>  being to check out a toolpath in a solids verifier program apart 
 JM>  from AutoCAD. The trick to me is to get a variety of programs that 
 JM>  do the individual functions well, (design, drafting, toolpath 
 JM>  generation, feedrate/auxillary function calculation, toolpath 
 JM>  verification, etc.) but that work together. When I couldn't find a 
 JM>  program to perform a function, I wrote it myself. For design and 
 JM>  drafting, and with a good bit of customization and lisp routines R12 
 JM>  is not bad.
 Forgive me - that sounds like a real slog, I admire what it says
 tho' all the bells and whistles with absolute minimal outlay -
 but it's not a direction industry can really follow ;-)
 -=> Ian >=-
Kind regards,
Internet : ian.underwood@esoftc.seuk.com
.!. Careful planning will never replace dumb luck.
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