Saturday, September 4, 2010

Revisions...the last post...I promise! and Working with XREFS

Revision File Naming

About a year back I raved on about revision problems created by the fact that a drawing file might contain many layout tabs, where sheet 1 might be rev B and sheet 2 might be rev D.

My approach for the last year, which I now admit is one that has a major fault, was to remame the actual drawing file name so it reflected the fact that it was a later revision. For example 150283D.dwg. The "D" would represent the most advanced revision. Into a folder marked "History" went the old files, for record purposes.

This worked well until the man in charge of maintenance requested that we go back to the old format of 150283.dwg, because he had that number listed in his database package called Mainpac.

My new system, from here on, is to saveas the drawing into the History Folder as "150238 as at 12Aug2010", and keep the current one always as "150238.dwg". Always a brain strain to remember to saveas!

As well, the principle of Xreffing goes astray if you start changing file names. Xreffing is something I had avoided because people in the future would come unstuck if the masters of IT ever changed a name of a drive. (They would never do that....would they?)

If they replace me in the future, then part of that person's job is to understand the concept of xrefs and how to fix them if the drive is reanamed. With this in mind, I have started to use them sparingly.

A Different Way of working, using xrefs

We have a 3D models of the plant in a folder marked "Plant-3D Models". Each major building has a name, eg "Melthouse" and the file name is the same as the building name.

My idea is to gradually build these up so that they represent a true and more or less accurate model of what is currently there. In these models, there are section tools, which write out 2D sectional views to the appropriate folder.

Our setup is further complicated because we have 2 sets of drawings-One for proposals and one for things actually built. So if something went from a proposal to reality, I would have to change my xref paths. A further gotcha is my 3 step method:

  1. Model with section tool.
  2. Outputted section file.
  3. Presentation drawing with outputted section file xreffed in.
The benefit of this seemingly overly complex method is that the process of updating the Presentation file is quick and easy: Change the model, write out the section file, reopen the Presentation file and everything is updated more or less automatically.

I have mentioned this in previous posts, but not in the same format!

At the moment this system seems to work, but sometimes the model gets cumbersome. For instance I might be working on the basement area, and you tend to trip over all the other stuff just looking at that. I'm thinking of a lisp routine that freezes layers according to their names- for instance Level1-Plant might get hidden when I want only level2 stuff showing. Yes, this can be done with layer filters and the layer manager. The trouble with the layer manager is that it seems to choose to turn off layers and not freeze them. As well, if you create new layers, you have to update the layer definition in the layer manager.

There are other problems: The detail required of a large plant layout is usually better to be of a low level, whereas for say a tank, I usually make this quite detailed. How to mix and match the two? I don't have an answer as yet. Possibly the answer lies in a 64Bit machine with 12Gigs...?

No comments: