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Is 3D any good ???. I’m losing the faith

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Just been having a rather heated debate with my manager regarding 3D CAD. I'm trying to push more seats of 3D into the company. He thinks we should shelve 3D and update the Autocad 2D systems.


I brought pro-engineer in to do a development project which envolved extensive use of sheetmetal, surfacing etc. Bitof a steep learning curve for a new user!!. Anyway, development project done, and I'm starting to use pro-engineer on project work.


The problem I have is that we are an original equipment manufacturer; therefore most project work relies on legacy data and using bought in items. I seem to be spending more time modelling legacy data and standard parts than actually doing any design. Therefore projects are taking longer than on the 2D system.


Is there anybody out there that is going of have been through the same situation?. Examples of ROI etc maybe.


Is it any quicker?.


Is pro-engineer (3D) suitable for OEM companies?.


Does anybody have any details of tips inmaking pro-engineer run slicker in a OEM environment?


Can anybody help?. There is now way I'm going back to 2D.
 
We just bought a division of Dana Corp and got all their design data in AutoCAD. 460 BOM, thousands of drawings.It was such a total disaster! Expolded dimensions with the text changed but the geometry not updated, missing dimensions, overconstrained features, out of date assembly drawings, contradicting drawings, etc. Many of the drawings were not even physically realizable, there is no way a real part could be made from these drawings! Not all these faults can be laid at the feet of the CAD system, a lot of it is up to the opperators, however, a good CAD system like Pro/E will prevent most of the errors.

I have spent nearly a year getting these parts redrawn in Pro/E. It has taken a lot of time but it is very much worth it. In many cases I had to reverse engineer the parts because the Dana prints were so bad. For the first time the machine operators have accurate process sheets and assembly drawings. We know up front how all the parts fit together, how much material is in the part, surface areas, clearances, etc. Is it a lot of work? Yes. Is it worth it? Absolutely.
 
Just to add some bottom line justification to my post above, quality is much improved, scrap is reduced, output is increased and we make money on a product line that lost money for Dana! It is not all due to Pro/E but you can not make a good part if you don't have a good drawing.

We had a similar internal experience when we converted from AutoCAD to Pro/E. Our AutoCAD drawings were in much better shape than Dana's but we still had out of date assemblies and all the other problems that come from just putting a bunch of dumb lines on a sheet of paper. Once you get over the hump of getting a majority of your components modeled in Pro/E the benifits start piling up.
Edited by: dr_gallup
 
Maybe another angle on the 2D vs 3D discussion here...


A large number ofour parts / assemblies were traditionally designed in 2D, since they're mainly pipes & cylinders (offshore completions). We've been on 3D for 3 years now, and a lot of ouractive assemblies arenow in 3D.


However, when new jobs come in, engineers/drafters tend to think in 2D & draw check layouts in 2D (autocad/sdrc) - then transfer onto Pro/E 3D. I'm trying to help people learn the 3D-first thought process... The current plan is to get involved in new projects and try to guide folks onto Pro/E earlier.


Any help +advice would be appreciated.
 
I LOVE these arguments, I have lived them first hand and somewhat hardened to them.
The argument that I always have with the 2D guys is that it is rare that these drawings are 100% correct when it comes to dimensions being actual and not fudged in. Most draftsmen are interested in creating pretty drawings and not parts that work.
I did 3d convert work for a company where the manager kept insisting that the ProE drawings I did for them were not correct because they did not match the 2d drawings. Allofthe dimensions on the drawing were impossible, such as holes that were off the part mostly due to the guy drafting was doing it in some scale and did not draw it correctly and forgot to fix the dimension. My favorite line from him was "we have been making that part since 1967 (or insert some year here) from that print so it has to be correct", yet when he would follow through with MFG found that the guys scaled it from the print. This I believeadds to the previous guys posted. Here is your bottom line argument:
The reason you use Cad is REUSE and SIMPLE Modification, by doing them in ProEngineer I have something I can easily reuse on future designs and we can modify the models and drawings very simply. Having a crappy 2d Drawing does not allow us to do so, espicially when the data is incorrect.
Count the money saved on re-work and time lost on bad drawings and it pays for itself. We calculated that we were able to save hours when it came to Engineering Changes if the models were in ProEngineer, you can change the drawings quickly and save hours a year in these costs. We tracked the ECNS before we started ProE and after and the number of hours ECNs took dropped well over 100 hours year. I think this is somewhere to start.
 
This story is the most redundant topic discussed in design departments. If you wanted to make your life easier, download AutobuildZ from thePTC website and read the manuals concerning the issue. It will enable you to convert from 2D to 3D easier and faster without the need for the whole process of sketching; holes; etc.<?:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" />
 
My example


I use Proe for DEsign conception and Mastercam for machinning.Never my detailled drawing was complete....WHY?.Because i prefer to concentrate my energy to design the new products


I always put in the drawing only the tolerances and the important dimension and transform the part in IGS and after send to machinning operation


100% parametric nature is needed to develop the new products


Let Autocad for the architecture....... and maps


I also totally agree with Dr Gallup


smiley36.gif



Cristelino
Edited by: cristelino
 
To Cristelino


Autocad is just as bad for architecture as it is for engineering. There are true architecture modelers such as Chief Architect from ART (Advanced Relational Technologies) that allow you to conceive spaces directly in 3d and do all the detailing and construction drawings in correct 3 views derived from a full 3d model.


The only reason Autocad is the industry standard is that it started early and eventually removed its copy protection thus making it at the same time the most widely pirated and the most widely sold GDS (General Drafting System).


Now that it is the de facto industry standard for architecture we find ourselves working in true 3d modeling systems and then converting drawings to DXF or IGES format that my be accesed by bleedin Acad in order to satisfy client requirements.
 
Good discussion. However, the CAD system is only as good as it's operator. Drawings in Pro-E can still suck. You must commit yourself to using created dimensions as a LAST resort. Models should be dimension driven not visa versa. The best investment you can make when buying a new CAD system is hiring (or contracting) a trained user and educating your current users. And by all means, don't forgo common sense in the name of expediency. Realize that quality work takes time. WYPFIWYG (what you pay for is what you get)
 
BTW


Autocad happens to have an excellent 3d modeling capability with an immensely improved user interface. Just for the heck of it I did a model airplane with Coons surfaces to define a very correct propeller and variable section wings. Piece of cake.


However, it's huge limitation is that it is not parametric in concept. That means that you can't go back and edit the section after you're done detailing the part. Can't reuse and modify. For that reason essentially, it is no competition for the solid modelers we consider adequate.
 
Here's a revolutionary thought.


Howabout letting the user decide on a case-by-case process.


I work turbomachinery and 2-D to develop engine cores (axi-symmmetric therefore essentially 2-D) is definitely the way to go. Engine dressing definitely 3-D.


In core engine 2-D is achieved by rotating or projecting out-of-plane geometry into the viewing plane. 2-D is definitely better for conceptual stuff.


Bottom line is I want the choice between 2-D and 3-D and I want software that supports this choice...


PS What are "Coons surfaces" ???
 
Pommares



I started with Autocad and i m proud i made in very complex model in 3D

But the limitation was hughe

After that i was mould designer using Euclid...........

Simple good mathematics but
no model tree .;; dificulty to save,rudimentary etc

But an excelent may be the best Machinning module until Matra Datavision was buyed by Dassaul System

So imagine all my frustration when i found finally Proe18........

7 years ago



But if you need very complicate schetch IN 2D Autocad is the best

ME 10 is not bad



I m sure for complicated instances of design Proe is Better in Architecture than Autocad



If you must realize a colonade in Ionic,Doric,or Corintic style is not easy in Autocad





OK?



But Autocad is the best for maps
smiley36.gif






Cristelino
 
Personally I'm all 3D (real life too). I come out of the PVC-profile business which was (and still is) essentially 2D. Looking to bring parametric modelling into this I finally developed ways to start with a 3D profile, making intelligent use of thin shelling, rounds and ribs. I'm pretty sure that my profile section is at least ready in the same time a 2D-er would do it, if not sooner. And when modifications are necessary, the 3D-model just reacts faster and more reliable than a draughter can move lines and recreate fillets and parallels.


As to dimensions : I favour the logic where the model drives the drawing. A model that is finalised shouldn't be modifiable by the draughter. And since the model is known to the drawing it is only a small step to open the model, apply changes and return to the drawing and let it update. The use of model dimensions directly in the drawing is preferable, particularly when it allows getting tolerances in. But I know from experience that the rules of robust parametric modelling not always coincide with dimensions on a drawing where you want them. So for the model you might need to dimension from a datum or from a certain edge,whereas the drawing needs a dimension from another edge, or does not have a visual reference for a key datum plane.


If ProE would have a decent way of doing simple drawing you wouldn't even consider mentioning Autocrap.


Alex
 
One benefit of using a poplular modeling software is the available resources from standard part vendors. You might be able to get Pro/E and/or IGES files for your standard parts, that would take some of that work out of your hands.
 
Jeff


Oh boy. I'd have to search my files a bit. That was a while back. It was just at the beginning of evaluating the options for solid modelers. And when I went with ProE, I never looked back. My positive comments on Autocad were just for the sake of being fair. Bottom line: ProEngineer any day.


But I will try to dig it up and post it.
 
Doug


A Coons surface is named after Steve Coons (a really nice guy, I'm glad they still honor him by using his name for that family of surfaces) who developed them at MIT in the late sixties, just when Sutherland was creating the first simulators. It is essentially the minimum curvature surface (think soap bubble) that can be stretched between four edges.


So to create a Coons surface, you create 2d or 3d curves for each one of four sides, and let the modeler define the surface for you. For instance, to create the upper half of a wing, you input the curve for the top side of the root, the trailing edge, the upper part of the tip and the leading edge; and you get the top half of your wing in return.
 
Jeff


Here are a couple of pictures of the aircraft and a construction connection detail that I did in Autocad to check out the capabilities of that system. Pretty decent 3d.


No way I would undertake a serious architecture project in that environment however; or in ProE or in SW. For that, there are real architecture modelers out there. If the client demands DXF, we just convert.


I'll try to get you an IGES file of the model. It's a bit involved as I no longer run Acad on my system and would have to borrow some time ona friend's machine. Also have to remember how that environment works. I'll give it a try. If not, is DXF any use to you?


Guy


2005-03-31_111725_T_40_trainer.zip


2005-03-31_111514_Anchor.zip
 
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