Stratagy for dealing with complex plant drawings

Joe Dunfee

First a bit of background.  I first learned CAD when there really were no standards.  Paperspace didn't even exist yet in AutoCAD. Of course, progress happens, and things change And, I am not too proud to say I don't know the best approach to everything.

Over the next year or so, I will be doing a lot of drawings for industrial food storage warehouses featuring frozen and cooled foods.  This will require perhaps 30 pages of drawings, and many layers of information. And while I have tried many approaches, I can't say I have been truely satisfied with any of them. 

In the past, with simpler projects, I simply put everything in one drawing, and had many layout pages and many layers. But, the larger projects are now making this a bit cumbersome.  I currently have 70 layers, and 25 pages, with at least another 10 pages and another 20 layers still to come.

Xrefs would seem to be the main approach to solving the problem. So I experimented with using Xrefs, but ran into the issue of dimensions not having anything to truly stick to.  I know all about associative dimensions  how they are only sometimes associative, and you cannot visually tell when it is no longer associative. At least when everything is housed in one drawing, and you need to stretch or reposition something, you can see the dimensions that are involved, and be sure to grab their nodes to stretch them. That alone made X-ref's undesirable.

Perhaps I should stick it out with Xrefs, since that is the main way people do it, and just manage the problems.  Or perhaps I should stick to my original approach, and accept the more complex drawing.

Does anyone care to share their own experience with drawings like this?  What is your approach?

-Joe

Joe Dunfee

 Once you hit "post" on this forum, you are forever committed.  I caught the misspelling of "strategy" in my title too late. Also, one occurrence of truly is also misspelled.

Actually, I think I can blame my spell checker, since it seems to lag behind quite a bit, and the fonts are too small for my eyes to catch the lettering of many words. 

-Joe

Knut Hohenberg

I also started quite a while ago (ACAD r10), and of course we kept different views and levels in one file back then.

But this was a real pain on the weak hardware, and switching to xrefs helped a bit. Nowadays, performance considerations are often not needed any more (at least for drafting), but I would still not switch back to the former approach, for a number of reasons:

- I like to be able to stack levels of a building quickly on top of each other for check-up.
- when drawing section and elevations, I can conveniently place the xref plans, no need for rotating the view etc.
- all drawings can have a common origin, also facilitating the overlay of drawings from other disciplines.
- teamwork is somehow possible (on a very rudimentary level, though).
- after small changes, no need to re-transmit drawings that stayed untouched.
- sometimes, performance still matters (I am traveling with a netbook)

The problem with dimensions is of course real, and not easy to solve. But I never came to like 'true' associative dimensions anyway - in AEC, you mostly dimension points where two or more objects meet, so the association is not always intuitive. For external chain-dimensions, I still use a script I wrote a long time ago, which generates defpoint-driven dimensions, and I keep dimensions in the same file as the geometry wherever possible.

As to the unchangeable posts and small fonts: I mostly write my comments in my editor of choice, and copy-paste them once I'm done.

Roy Klein Gebbinck

@ Joe:
Are you using xrefs for each building level (as Knut described) or for each discipline (structural steel, exterior walls, interior walls, ductwork etc.).

Joe Dunfee

My trial with an X-ref involved putting the geometry of the building and the refrigerated chamber in the X-ref, along with the dimensions for the building. Then, my intent was to create a separate DWG with more details added.  I might only add 2 or 3 of these extra DWG Files, so that if I need to edit them because the geometry of the building was changed, then I would only need to do it a few places.

But, in my case, I abandoned the attempt before I worked much with it.  I was hoping someone here might describe a method that I had overlooked.

As I think more about it, the ability to save layer states, and add a large number of layout tabs is manageable  even if it is is a bit cumbersome. I have not had performance issues yet.  So, a single large file is still viable   It may actually be a draw, in terms of the ratio of benefits/problems if I compare it to using Xrefs.  But, since I am more familiar with working without X-refs, that probably keeps my vote in favor of my existing method.

-Joe