3D CAD Problems

The story below is from Ralph Grabowski's weekly newsletter, upFront eZine, The Business of CAD.

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A Short History of 3D CAD at Our Company by L.A.
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Our medium-size consulting engineering company in South Africa specializes in mining work. We produce 2D drawings in AutoCAD, but accommodate client requirements to use alternative software.

My first project at this company was a platinum concentrator. We used the 3D mechanical CAD software required by the client. We battled massive file sizes: it could take hours to open a model, and even longer to produce a 2D draft. We had guys working night shift to use quiet server time. We found a continual problem with linking the model to the draft; when we broke the link (to give more flexibility on the drawing), then all further model changes were lost.

As the job moved into the construction phase, the 3D CAD software was installed on-site, but the site crew hardly used it -- preferring the paper drawings. I worked on-site for a few weeks. Whenever I opened the model, a crowd gathered around my monitor, but tended to wander off when it took 20 minutes to do a refresh. It proved difficult to convince the site guys to buy-in to the 3D concept; it did not help when head office made the site's system read-only. The project was finally completed without too much trouble, apart from the normal hiccups like the electrical guys running cables through the pipe reserve.

Around this time, our company decided to offer customers a 3D package as part of our services. After much debate over the best software to suit out requirements, we chose Intergraph's PDMS. An authorized training center sent teams of trainers to train eight of us in all aspects of the program. (I was designated for 2D and isometric drafting training.) We spent three months in non-stop training -- not a good idea, as after three weeks we suffered from information overload. Unfortunately, the local training office closed down shortly after our training ended, and now all communication is from the United Kingdom.

At this time, the big project we had been hoping for was postponed (and eventually canceled). The projected role for PDMS was curtailed, and we all ended up back on a project with the former 3D CAD software. Our company installed the latest top-of-the-line IBM black boxes, which did help with modeling time. It also helped to have a cup of tea while waiting for the model to update.

The company wanted to try out PDMS before our skills were lost, and so a client was offered a portion of the job to be completed on PDMS at no additional cost. The client accepted, but as we started this project we realized just how little we knew. The training never seemed to cover the problems that arose. Simple stuff, like trying to insert the client's logo. After days of effort, we traced over it with 2D lines. Database setups were a black art that took us weeks to sort out.

We managed to get the model looking rather good. We used the Review module to put together a flythru that really impressed the client. We attached textures and colors to the model, and even got the client to signoff snapshots of the model as Approved for Design.

As we progressed from modeling to producing 2D drafts, the wheels fell off. Our 2D drafts were of such poor quality that the chief draftsman would not allow them out the office. We battled to put together a set of decent drawings. It took us weeks to build a general arrangement. In the end we ran out of time; we had to hand over the drawings to the AutoCAD guys, and they knocked out the drawings within a few days.

The Isodraft package was better -- at least our isometric drawings were issued for construction -- but some of the final isos were touched up with black pens, because I couldn't get the package to do what I wanted. We spent hours on the phone to the UK help desk, but they rarely gave us a solution. Usually, we got a workaround or a question in reply: "Why do you want to do that?"

The job is now in construction phase, and I'm emailing JPEGs to the site office. We offered the next phase of the job to the client (again for no charge) but they declined. Of the eight guys that took the original PDMS training, four have left. Of the remaining four, we tried to take over their portfolios, but unless we get a job that dictates we use PDMS, then it looks like it will be shelved.

>From my experiences, I have these questions:

Q1. Do 3D jobs still need to follow the normal route of producing general arrangements, and then 2D details and isometrics?

Q2. Do companies using the 3D concept produce 2Ds from the model, or do they use AutoCAD (or similar) for the drafts?

Q3. Has anyone ever produced a good PDMS 2D general arrangement comparable to, say, an AutoCAD drawing?

Q4. Do 3D modelers have to be multidisciplinary, or does a piper only do piping, and a structural guy only structures?

I always wonder if the best 3D guys are IT specialists with a bit of drafting knowledge, or "drafties" with a bit of IT knowledge. I fall into the latter category: I can spot the difference between 150# and 300# flanges at 20 paces, but I don't know how many zeros there are in a tetrabyte.

(L.A. is a drafter at a South African consulting engineering firm whose name he'd rather not make public.) Received on Tue Sep 28 01:33:00 2004